Gus Potter

In almost all cases for a domestic dwelling (not flats which often share a common stack) it is a BC requirement. Here is some info which I hope helps BH members. In Scotland for example the regs point you to BS EN 12056 part 2 which is to do with drainage inside buildings. Comply with this code and you are well on your way to complying with the regs. There used to be great stuff and diagrams in the regs to help self builders /renovators but these are getting progressivly stripped out. Here are a few thoughs / observations. If you get a feel for the principles then you can adapt to suit your needs. Often you see a drain pipe poking out the roof..with a grill on top to prevent birds nesting and so on.. the top of the main stack. This open vent serves two purposes. One is to prevent excessive suction building up in the main drain line serving your house the other is to prevent over pressure in the line which will blow the traps.. and worse. Pressure can build up in a main drain line; if the wind is blowing the wrong way down stream (other folk doing daft things like facing a vent stack into the wind), if you have a blockage and a build up of gas (could be a gas leak too and the gas migrates into the drain! nice to vent outside than into your house) down stream if say your neighbour has been putting nappies down the drain. They get the drain folk in and they put a pressure washer down the pipe.. I'll leave the rest of the description for now as to much information can be uncomfortable. Commonly though it's suction that causes the issue. There are a number of ways you can design a drainage system. Some work on what we call "full bore flow" this is more common in the EU except for some roof drainage systems in the UK... you often see these full bore roof systems described as "syphonic systems" in the UK, some toilets work this way but just within the "bowl". Mainly though in the UK we design the drains in our houses (system iii) to not run full bore and thus they don't generate this true syphonic effect. But they do still generate some negative /positive pressure. When you pull the plug on the bath the water flows and pretty much fills the pipe. As the water moves down the pipe it compresses the air in front of it. If you don't relieve this compression it can blow the traps on say a sink in another room and thus fumes will enter that room. Some air passes over the top of the water in the pipe as it is not running full bore but often not enough. Commonly a sink trap has a shallow seal of water so we are only taking about a small amount of pressure, much less than say a car tyre or you blowing up a balloon. Once the bath is nearly empty if the pipe run is long then you have this body of water still moving down the pipe and this creates a suction effect behind it which keeps drawing water. This "residual suction" can be enough to stop the bath trap from filling properly at the end of the drain cycle and not creating a proper water seal. This means that when you say next flush the toilet the smells come out the bath trap rather than venting out through the stack. If the seal is completely broken (the trap is not filled enough) then you invite "lingering" odours from your own house and that of your neighbours unless you have your own private sewage system, in which case it's you own personal "gas". One way we get around this is to fit an air admittance valve on branch lines, say on a long run to a kitchen sink or ensuite bathroom. This works a bit like a snorkle in reverse. It is sensitive enough to let air in but not pressure (smells) out. This allows the trap to fill properly from say the last bit of water in the bath and create a seal. Now one problem arises with AAV's is that the regs require them to be set above the level of the spill over point. For example in a bathroom the idea is that the home owner will see the sink spilling over if they have a blockage rather than the AAV leaking and causing hidden damage. Now that all makes common sense. Some of the building regs are really good! But this does not fit well with modern bathroom and kitchen design as no one seems to want a "box in the corner" of their new sleek vanity unit or kitchen work top. I mentioned adapting previously. Sometimes you can implement an old solution that was commonly found in tenement flats. This is called a "loop vent". Here you create a circuit of pipe in a loop. The top part of the loop does not carry water, it just lets air circulate. Have a look on the internet for loop vent design.. kitchen designers with island units have picked up on this, reinvented the wheel and are punting this as some kind of great new invention. Ashthekid.. hope this give you and BH folk some background info. Oh, and there have been a few other posts on BH about pipe gradients etc...

Can you turn the cross walls into load bearing walls? It already sounds like you are intending that the cross walls should provide lateral stability to the external walls. i.e they are shear walls. Build these in timber frame if you like. Roughly where the ceiling ties join the rafters can you stick in a purlin running in the direction parallel to the long walls? The purlin is supported on the cross walls. The purlin can sit above or below the node point to the ceiling tie / rafter. These purlins take out all the spread out of the roof and carry the majority of the vertical load. Not you have relieved most of the load off wall that is causing problems and you can work on it as and when you like. It's (the ropey wall) pretty much left to carry it's own self weight and a small portion of rafter load from the bottom two or three feet of slates / sarking. The same principles can be used for loft conversions where the roof is required to carry heavier loads. This may work fine or you can often adapt the principle to suit the layout.

Hello Rob. There are no daft questions, it's daft not to ask in fact. I hope this helps to add to your research knowledge. To add to the great informative comments from other posts I'll touch on the structural side of things. I'll do a bit of general stuff first (tell a story) and then focus a bit on what you have. A bit of background on agricultural buildings... lets go "back to the second world war" Very roughly.. and there are a good few bits missing from the following but I've written this to take you hopefully on the "Build Hub Journey" When this war started the steel industry were a bit more advanced in the quality of the material they were producing. They went to Churchill (well not him really but it sounds good) and said.. look we need steel for the war effort. We have moved on from making steel in our back garden and now have "quality control" so our steel is more reliable and less varaible in quality. As it is less variable allow us to reduce the factors of safety we need to apply. This way we will use less steel for building domestic structures and there will be more available for making tanks etc. I will stand corrected but the Gov said OK. Now the concrete folk said...hang on that's not fair as we are all at war.. let us too reduce our safety factors..but they were still making concrete in their "back garden". In essence in a war situation Chuchhill said OK although there was no rational safety basis for doing so. The only basis was that we were in a war.. frankly, if we had lost it we would have much more to worry about than safety factors of concrete and steel design. Moving on..Rationing was still in place after the war and for a while folk still had ration cards, eating powdered eggs and so on. Folk wanted to see some improvement.. There was a push to mechanise farms, improve production. farmers made hay. Barns were needed to house grains and live stock. No one gave two hoots about the quality of the barn stuctures as the populase were restless and demanded a higher standard of diet. The demand was immediate not least politically. Over the next few decades the insurance industry clocked that they were having to shell out for barns say that were say "falling down" too often. Maybe they woke up to the fact that farmers are quite canny, were stuffing them and "having a laugh".. One part of the solution was to start to bring agicultural barns into the "building regs" They started to codify the design. One other driver for this was also that a lot of kids / young men were getting killed on farms back then. It was what we would call today "carnage" What then happened to some extent was that the farmers went "mental" and said if you impose these regs on us the food price is going to go up. I think a compromise was reached where the farmers got a half way house and this manifests today in the modern agicultural code BS 5502 part 22.BS EN 5502. A key thing about this code is that agricultural building design is based on lower loadings, a lower what we call "occupancy rate" , and have no proscribed deflection limits..the amount it sways / deflection. Deflection is critical if you want to use the same frame for a house. It may not fall down but it will move so much that it will burst your cladding fixings and the place will leak like a sieve. Have a look at modern cladding systems, they all have caveats on deflection. If that is not enough then go back to the loadings and occupancy rates.. they are often not compatible with the regs for modern housing roof loads and so on. As an aside jump now to 1980's. Here (and it still happens from time to time) we were getting a lot of "fake sections" from Asia. They are hard to spot, they look like a BS standard sections.. put a micrometer on the flanges and they are thin! Also they had a lot of impurities in the steel which compromises the welding. They are a "shoogly peg" to hang your new house off. Rob and for all. In reality nine times out of ten you''ll find that the frames are of no use structurally. If you want to delve down an SE will want to look at the base connections, have to make safe assumptions on the quality of the steel / oak frame / timber / concrete degredation / the size of the founds. Then the SE has to look at whether they can sign off on the fact that what you have will last for another 50 years which is often a lender requirement. Also remember that in the case of timbers when you alter the ground level, moisture content and let in air you can promote decay in timbers. timbers buiried in the ground will last for hundreds if not thousands of years.. look at some of the old oak piles etc found in the Thames.. all good until you let the air get at them. To sum up. I would start out by investigating the ins and out's. It's a pity that the planners in some cases insist on the retention of a building frame that has no historic value and is no longer serviceable. They fail to recognise that by trying to retain a frame that has outlived it's service life is actually bad for the environment, can prevent young folk getting on the housing ladder and so on. Rob. Lastly you have a fair mix of frames and different constructions. If you want post some photos of the concrete clad frames.. would be interested to see what you have to work with. Oh and if you are converting an old barn there were just as many chancers cutting corners in the past as there are now so proceed with that in mind.

Hi Blynchy. BH is a huge resource. It's stunning how much real practical info is here. There is a great mix of folk here. You'll always learn something here. I do each time I visit. Sounds like you are starting out on a journey. Best thing to do is to try and get familiar with the search function on BH..it's not google.. not commercial (so far) so you can find some really eclectic and valuable stuff. You'll need to spend a bit of time raking about but in doing so you'll pick up info on a pile of stuff and the next steps once you get moving on the build. A bit of time spent here will probably save you a fortune. Don't forget that building something yourself should be fun too. All the best.

Hello all. A lot of the following is general info which I hope will be of help if your builder has not done what they should have, or "done what they think is helpful"..some builders do this.. believe it or not. There are a lot of young (still some older ones too) builders that are really keen to please and keen to do the right thing. Their heart is in the right place. Yes it's an interesting subject this..for a good number of reasons. Unfortunately for Loz.. it's Loz's house we are talking about / discussing. Loz.. I was prompted to make the post about the timber grade as for me this takes you back to basics, can take heat out of any potential situation. No point in looking at load span tables etc if you have done something that has changed the intergrity / "provenance" of a component on which the load span tables rely on. Loz.. you mention that the SE is friendly with the builder. This is a normal occurence. SE's / Architect's / Designers / M&E specialists and so on like to work with good builders.. and builders like to work with good designers that can resolve; unforseen on site issues, be able to design and specify easily available materials and so on. That eases the way for everyone.. Also remember that builders can often be members of professional bodies / have extensive professional knowledge. Just because they may wear "shorts to work" does not mean they are unprofessional or lack knowledge! In fact the last few designers I've talked to have all been in shorts! .. COVID you see. For designers and builders (major contractors too) trust and professional respect for each other is built up over time and this has value. In particular, it often drives down the cost to the Client and this is how you get repeat work and recommendation from a Client. Every one is a winner to some degree. In summary don't worry at this stage that the builder, SE, BC officer may have a good friendly relationship. This is far removed from what we would call a corrupt relationship..for which you can not only be stuck off a professional register but also invite a holiday for yourself at a location chosen by our Monarch. Loz and all. Often you find that you know something is not right.. you just know this as a lay person.. you don't need to be an SE say.. trust your gut and ask questions, as you are doing. Loz, the builder may know that too. At one end they may know about the timber grade etc and just tried to pull the wool over your eyes. If they do know about the timber grading it would be a new thing for me though.. Your SE should have some awareness. At the other end they (builder) may have thought they were doing a good thing and solving problems.. helping you out. @saveasteading "Agreed. Mistakes happen and it is sometimes reasonable to find a solution that does not inconvenience the builder. " To add a bit to saveasteading's point. I'll use an example, corollary here. You can often deal with a home warrantly provider who is giving you the "run around". Often you encounter arguements such as "well the cracking you see is visually acceptable" or "some amount of settlement always happens". Dig deep into this and the modern Euro codes introduce a way of designing where deflections and settlements are more open to interpretation provided the structure remains safe! What this means is that often the domestic home owner has an expectation that is not met.. the developer/ builder is off the hook to a large extent unless the home owner is willing to spend a lot making a counter argument. Loz..you could find yourself in the position where the onus falls on you to make the case showing that you may have a "bouncy floor" and or a ceiling that cracks in a few years time for example. One key to unlocking this is to find something that you can point to that has compromised the structural safety. This is non negotiable as it is a UK legal requirement. Nail this and you often find that all the other arguments made become mute. This gives you the big stick as often to fix a structural safety issue you have to strip out and reinstate. Basically you cut the feet from under them. Loz in your case this timber grading thing may be the key to resolving this. Now you have the big stick and you can decide how to use it. But go gentle, particularly if it's been a genuine mistake. Always remember that if you use the stick half way though a project then if you make a mistake later then the builder etc will probably return the favour with a bit extra! Always ask yourself "what is fair and reasonable behavour? Be wise. Loz..Here are a some choices the SE may have. 1/ Be competant to visually grade the timber in it's cut down state (old school stuff but can be done still), recheck the strength / deflection which will now probably fail on overall deflection and look at the vibration. Then produce the calcs and evidence followed by sign off. 2/ Get a certified person from a timber merchants / producer (grade it and then perform the above checks) to do it for them.. the rub will be to make sure that the visual grading will still also be CE compliant.. good luck to the SE on that one. 3/ Chuck in the towel and look for another solution. Loz.. as promised.. here is something worth exploring. If you can accept a small reduction in the ceiling height then bolt onto the sides of the joists you have new 195 x 45 timbers. Alternate which side you bolt the timbers to. Bolt them all the same, say on the left hand side and you will get a rolling effect which is not desirable. Your SE should know this but the builder possibly won't. For the technically minded this rolling effect will happen as you shift both the centre of gravity of the section and the shear centre of what is now a composite section. Loz looking at the floor you have the joist sizing is probably governed by what we call the bending moment and deflection. In other words are the joists strong enough in the middle not to snap under load as they get bent and are the joists stiff enough so that the floor does not bounce too much. Where the joists frame into the supporting walls then you have what is called "shear effects". There is a good chance that the SE can show that at the ends of the joists they will still be ok in shear even though they have been effectively notched on top. Simon mentions this too but unless you have some other loads acting on the floor from above it all may be fine when the SE checks the shear at the joist ends. To expand on other posts on doubling up joists and so on. On the practical side when you offer up the new joists put plenty glue on the top side so they stick to the flooring . Now get the builder to run upstairs and screw the flooring to the new smooth surface of the extra joists before the glue takes up.. this will mitigate the squeeks. Yes, you'll need new noggings mid span (dwangs) but that is a small price to pay. I think you could resolve this fairly easily. It won't cost too much cf knocking holes in the masonry, potential disturbance to the masonry, lifting the floor and so on. Often the key here is to find the big stick. Show you have one and avoid using it, mainly because you often still need to finish the job. Also, if your builder has just made a genuine mistake then it's a fair and moral thing to do. Lastly Loz if your SE comes back and says the joists are failing at the ends due to shear then there are other options open such as using a ledger piece and so on. To finish on a positive note. Many projects encounter problems which can be resolved with a will and in an equitable way.

Hello Loz. Sorry to hear about you dilemma. Your starting point here is to take another step backwards and understand what the implications are in terms of what happens to the declared strength of the timber when you rip a bit off the top / bottom / sides along the length. Typical structural timber for extensions and the like comes in grades.. you'll often see it stamped C16 or C24. When it is produced each length is put through a stress grading machine which applies a force. Sensors measure how much the timber bends or if it just snaps. If it comes out the end of the machine with the correct reading it gets a stamp to say what grade it is. Now timber has knots / wane / the grain weaves about and so on. You could say have a piece of timber with two knots near the centre but good grain top and bottom which passes the grading. Cut 40mm off the top and now the knots are in the high stress zone for bending so the timber can fail. In summary if you rip a bit lengthways of a stamped piece of timber the grading is no longer valid. You can notch it but there are rules which apply to where and how much you can notch timbers. Point this out to the SE / BC officer and see if they will still pass the joists given that the stress grading is probably invalid.

Hello Pierrick. Welcome to Build Hub. Here are a few thoughts. Are you sure the walls you want to take away are "non load bearing". A key thing here is to recognise that although the walls you want to take away may not be carrying any direct vertical load from above they may be providing lateral stability to the walls that are carrying vertical load. For all. If you take a ruler, stand it up on and press down from the top then the ruler bends. Remember how hard you pressed down. Now get someone to hold it steady in the middle and press down again. You'll find that the ruler will take about four times the vertical load. The maths of this can be attributed to the mathematician..Euler.. a pretty famous guy if you are an SE. Now if you look at how many bits of wall are to be removed to form the open plan area you have to ask the question.. are any of these walls contributing to the stability of the vertical load bearing walls? The next thing to do is to look to see if the non load bearing walls are contributing to what we often call the sway stability of the building. When the wind blows for example it pushes the building sideways. This has to be resisted by the walls or structural frame which could be say a steel frame working alone, or a steel frame with stiffening panels between the columns or a brick building with internal stiffening walls. Pierrick I think you need to establish this first. If you don't at some point someone like me is going to ask the same questions. If it turns out that you can demonstrate that your proposals will be structurally safe then you have taken the high ground. This seems like a case where you are in dispute with say a home warranty provider. They partly rely on a war of attrition to grind folk down, hope they run out of money etc..if you get the structural side sorted then you can turn this around..run up their fees and this can concentrate their minds. Once you have the structural stability side sorted then you have the fire regs. Now an SE should be able to deal with this also. If they can show that structurally, even though the walls are "non loadbearing" that they have maintained/ remediated the fire protection between the floors for example.. by say producing drawings that show how they have maintained the fire protection where you have removed the non load bearing walls. In other words when a non load bearing wall is removed it can leave a gap in the ceiling which needs filled in properly. Make sure you can comply with the rest of the regs before paying for an SE. Once you have this SE support in place you can then press then for a proper response.

Hello saveasteading. That's interesting what you're doing so would like to hear more! I was wondering if that stone you have is Chert. Not sure though, but the way the face splits looks a bit conchoidal. If so it will be pretty hard as you know. Also, the surface is smoother so the lime mortar gets less of a grip thus although a hard stone each piece can come loose easily once you start say coring with the associated vibration. I've read a few of your posts (and responded after a fashion) and appreciate your knowledge. I wonder. If you have seven holes to do then it's sods law that some will locate under parts of the wall where you are changing the loading a bit and thus introducing more concentrated loads.. say by widening doors, near piers between windows and so on. "We will be protecting and filling that eroded edge." Have you worked out how you are going to protect the exposed edge of the wall? This could well be your starting point so if you nut that out a solution for the service penetrations may just offer it's self up. In an ideal world you want to leave the origonal stone in place.. maybe just because it's a good moral thing to do and keeps the ethos of saving a steading? Here is a few thoughts for all. Often on BH you hear much about clay soils which shrink and swell, they can be prone to long term settlement and so on. Trees for example can remove moisture from the ground causing the clay to shrink. When you cut down a big tree the moisture content of the soil can rise.. the clay swells up, often with great force which can lift things in an "undesirable" way. Sands and gravels are a different animal. Being simplistic (big subject) they are not generally prone to swelling and shrinkage. I'll leave frost action out as this is also an expansive subject but important if you have a BC officer who insists on a certain foundation depth to prevent frost heave.. So sand and gravels..can be good news but there is often no free lunch, well there can be but.. Sands and gravels derive much of their ability to bear load, say from a house foundation by the "friction" action between the particles. Each particle has a mass and this rests on the one below and presses / interlocks against the one each side so friction / interlock is generated. In the ground the stresses act in three dimensions, up.. down, left and right. If you fill a glass with sand and push down from the top it will bear weight. Take the glass away and the sand column will collapse. This is often called "confining" . In other words for a foundation the ability of the sand / gravel to bear load is partly determined by not just what is below but also to the sides and above. Importantly if you lower ground level you loose the dead weight of what is above (surcharge) and this can have a significant impact on how much load you can put on the soil. Now to generate friction between the particles we need mass and this comes from the density of each particle. But we know boats float..hopefully.. Archimedes. Now if you have a house and the water table is well down then you get the full mass of each partical of sand acting on it's neighbour. Raise the water table and now the relative density of each particle is roughly halved.. thus half the bearing capacity. SE's use this as a rule of thumb and it's one of the first questions asked.. where is the water table (and where could it be in the future) if building on sands and gravels. That's a bit of theory but applicable to say an old steading and also virgin ground. You also can get a bit of a "cementing effect". Here for example minerals will weave their way between the particles of sands and gravels and create more of a bonding effect so you get friction and bonding. It's very hard to test for this as testing is often intrusive and breaks the bonds and by the time it reaches the lab say it's lost it's mojo! We know these old buildings have stood for years but it's harder to prove why from basic tests. But we know they stand up. On a positive note.. a building will use every alternative load path to stay up before it falls down..but don't erode this factor of safety.. it's last resort stuff. Turning back to the practical side and in particular a typical Scottish steading construction. These were buildings to house animals / sometimes folk too and thus you can imagine that when they were build no one could forsee that they would have the value they now do. You have a "water proof" outer skin, random rubble interior and an inner leaf of stone that is less dressed and often less well bonded. The walls vary in thickness depending on their height and amount of buttressing from the interior walls. For these walls to work in simplistic terms they have to function in a number of dimensions. When you load the wall from above the load spreads out sideways. Often the vertical load is not central on the wall head so this causes a shearing effect between the layers as they work to share the load. When the wind blows the walls bend and this also causes a shearing effect between the layers in both a vertical and horizontal direction. For the keen this is sometimes called "complimentary shear". Remove material from one side of the wall and you loose the surcharge.. you invite movement between say the inside and outside of the wall. Vertical shear effects are introduced and the wall may protest. To quantify the above.. fairly recently a Black House fell down on one of the Islands. It was built on sand / gravel and lets face it although they sound great they were built with the few resources available at the time. They have an different way of dealing with driving rain permeating the walls but it's a good example of what you need to watch out for when doing up old steadings. Here apparently the builder had excavated out the inside down some 400mm, just to the level of the stone found. But removal of that small amount of surchage caused the sand to weaken on the inside, vertical shears built up in the wall, the layers delaminated and the thing fell down. Maybe the builder had a machine in, maybe there were some big boulders that were "eased" out when no one was looking" Who knows the whole storey. Luckily no one was hurt. If you've read this far then thanks and if you are thinking about doing up a steading in Scotland then I hope this helps. If you can grasp the basics it's a great journey and can give you confidence. Saveasteading.. sounds like you have a fairly robust structure so you may be fine. Would be interested to see how you are going to protect the exposed part of the wall and so on. Maybe as I said earlier it's a case of starting at the end, edge protection for frost / support and working back from there? Oh and do you know what stone it is and where it came from?

Hello offthepiste. That's a good size of a house! If you are inclined to take everthing with a pinch of salt then here is some fun stuff you can check out when taking on a renovation of a victorian house. Imagine you are a prosperous Victorian (or small developer).. you commision a house. The Contractor would often turn up with a pattern book with different designs; room sizes, roof shapes, ceiling heights, cornices etc. You would pick what you liked. The builder would then look up a book that told him that if he made the walls X inches thick, used floor joists Y inches thick and foundations Z inches wide it would all be ok... if the ground was suitable. The builder would then give you a cost for this. Now for the founds. These were hand dug down a bit until the soil looked about right. Then often a labourer would go round with a tamper and whack down the soft spots. But they drank a lot in those days and worked six days so if your founds were done on a Saturday or a Monday then maybe like a British Leyland car.. they used to say..avoid a Friday and Monday built car. The mason would then come along, slap down some mortar and often build a stepped foundation. The rest of the house would go on top. Remember though that the Victorains built some substancial structures and had some pretty nifty mathematical methods of structural analysis available to then .. it's just that from time to time the house building market lagged behind as it still does in some respects, particularly when considering the quality of workmanship. One key is to understand fully how the house is built and what materials have been used in it's construction. Also, what it rests on on ground wise, the slope of the ground round about how the drains work and other environmental factors such as big trees and if you neighbours have done something that may "upset" your house. Get to the bottom of this and you can you can move forward in an informed way. You know that as soon as you start introducing insulation into this old house you'll change the "moisture" regime.. and that has to be managed / designed to achieve the outcome you wish. From a SE point of view the Victorian builders used rules of thumb. One for example is take the span of a floor joist in feet. Say 14 feet. Divide 14 by 2 gives 7. Add 2 inches = 9 inches. Thus as a rough guide for a 14 foot span you'll need a 9 x 2 in joist at 18 in centres. At that joist spacing you can also add a bit of extra dead load. You can stretch them to 2 ft centres. For a rafter it's the same but you only add one inch to the depth rather than two. We still use many of the old rules of thumb when doing preliminary fag packet sizing. Now we use metric units in the UK so the preliminary sizing formula look a bit odd. If you can get a handle on how the house stays up then that will help you. Hopefully the above will give you an insight. This will then give you a feel for where you can add load, say heavy water tanks, where you maybe want to review and spend money to the best effect. There is also what we call building stability.. what stops the house from moving sideways but I'll leave that for now. Hopefully the above will give you an insight. Once you nut out the basics.. ground, super structure, insulation and moisture control you can then start to develop how you are going to mitigate the energy usage / "carbon foot print". Lastly, if you have been lurking on BH for "tooooo long" you'll know that it's time to step up to the plate and post some photos! All the best though.. sounds like a great adventure.

Spot on. One key is to make sure you enjoy the journey and have as much fun as you can. Learn as much as you can by doing your research. Post some photos and you'll get plenty input from BH members.. All the best.

Hello newby2. No it's understandable that you may have a touch of the "jitters" at first. The main thing is to do a bit of research before you jump to any conclusion. All buildings move about as they are "elastic structures".. they bend, shrink, foundations settle / move about and so on and this manifests often as cracks. This crops up very often when folk are in dispute with say a warrantly provider on a new house. One of my go to references is BRE Digest 251 Assessment of damage in low rise buildings. It's an older document but it's a great guide on cracks in houses. It's 8 pages long and written in plain English. You can buy it for £15.00 from the BRE bookshop, apparently it is also "google able"... For all.. this is a great document to have a read of, whether you are building a new house, extending or just curious. Have a read at this newby2 and it may fill in the missing piece of the jigsaw.

Peter.. your eye is remarcable! the cut ridge tile. Ryan. Technically you could get out all the standards, manufacture's info and see if it complies. That will take a lot of time an effort. Even if you do this you often come up against the phrase " visually acceptable" and that is an issue.. acceptable to whom? Just a question as the photo is not that high resolution. Are there some really narrow cuts in the roof? In other words are the side laps ok? In other words we know that up and down the roof the tiles / slates need to over lap the ones below by a certain amount. But they also need to overlap sideways.. parallel to the ridge by a certain amount. You can get this side lap size from the manufacture's data sheet. If all ok then once it's weathered a bit then it will mostly all blend in.

Sorry to hear that. Although they are both "technically " right it's a poor show. Assuming you are a domestic Client. Generally the expectation professionally, under the CDM regulations and the consumer protection act is that if you are a domestic client you are afforded some leaway compared with say a builder who is an experienced Client... They should be communicating (that is covered under the CDM regulations) with each other, that is part of their job. Even if they have gone in too low quote wise then as a Domestic Client how are you to know what is a fair rate. It's shoddy on both their parts and they are potentially leaving themselves open to trouble. If you want you can look up some of the things I mention above then.. drop them a pleasant but firm note. It's ok to say you don't understand some things.. but that you do understand that it is their job to make sure all is coordinated and safe. If no response then you may wish to consider binning them both as when it comes to the doing the work you'll probably get no support from them if the builder goes off track. If you do bin them then you'll be in a better position to ask for any monies to be refunded. Hope it all works out, it may just be a hiccup lost email or something else benign.

Hi Tom. Yes it could be something simple. Check the things you can, even just to know you have not missed something blindingly obvious, before you start spending on fees / further testing etc.

Hello Internet Known How. As a bit of background you probably know about the "45 degree rule" This is a kind of rule of thumb which assumes that any load from a party wall or foundation say spreads out at 45 degrees thus if you are 3.0m away from a party wall or neighbours found you can dig happily down 3.0m. But this is not always the case and this is where the issues arise. As a bit of background. If you tip out a load of broken jagged brick from a lorry it will form a pile. The sides may slope at some 40 degrees. Tip out a load of round gravel and the pile will spread further, the sides being less of a slope. Tip out a load of custard and the slope of the sides will be pretty shallow. This is called the "angle of repose" and it is roughly related to the shear strength of soils. Much will depend on the type of soil. You could have a stiff boulder clay / good chalk ( goodish shear strength) and this will allow you to dig deeper and closer so long as you don't leave the excavation open for too long. A soft / sensitive / high plasticity clay found often in the South East say can behave a bit like custard under certain conditions so the 45 degress rule can be no longer valid. The bearing capacity of a foundation changes depending on how much soil is above it. If the ground slips you can remove / change this extra weight on top which is confining the soil around the found. You also have to look at where the water table is for example..it can be quite complex as when you change this water level it can make the ground behave in a different way. It would be worthwhile having a chat with your SE and get them on board. They may not even charge you for this and give you good pointers. One aim here is to reign in the Surveyors, focus minds and hopefully speed up the process. Also, by doing so you can show you are acting in a responsible manner and this can carry some weight. On a light hearted note to finish.. if your SE mentions custard then ask if porrage behaves the same.

Hi Tom A few thoughts.. If you can taste and see the physical rusting you need to get to the root cause of it..on the upside you can be "Columbo" or Miss Marple.. Your starting point is often to look at the obvious and rule things out. Here are few: 1/ Have you done anything in the house that may have impacted on the internal plumbing..is your boiler leaking system water into the potable water?.. do you have modern or old pipework? 2/ Is pipe from the head of the bore to the house ok, is it leaking and syphoning back say and drawing surface ground water in? 3/ Is the cover to the borehole sealed ok. 4/ Is the bore cased at the top and is the casing falling apart. 5/ Is the bore hole pump falling to bits. 6/ How deep is the bore hole. Very deep and it could be in the lower aquifer, shallow maybe in a perched water table..the two behave differently as they can draw the water from far away or close by respectively. Worth a bit of time researching this. 7/ Have a walk about.. in your garden first.. have you been using any fertilisers or chemicals? next.. what have your neighbours been up to? Have any local farmers etc been "improving the soil" or using the likes of iron suplhates? 8/ Has there been development going on round about you that could have altered the ground water regime. 9/ Any factories shutting down (mines used to be an issue but not many of them left) that have been pumping the ground water. When they stop the ground water rises and can flush stuff out to your bore hole. 10/ Has anything been poured down drains you own and other folks too. Drains / soakaways leak so consider this. I'll stop at ten things but if you can rule these out and think of a few more yourself then you could save yourself a bit of cash on professional fees. Just put together a small package of info you have and this will often serve you well. All the best and stick to the bottled water until you get to the bottom of it.

CPD makes some good points and gives good advice here. Slating turrets is an art. If you want to have a word with the Slater then be familiar as to what is underneath.. maybe the first thing the Slater will do is to blame the joiner! The turret is a key feature and it needs to be right, often they are right over the front door.. not a good first impression. Ask the Slater if it would be ok on their own house? There are full turrets, half turrets and others and each needs a slightly different approach. If you have a full turret and are in a bind then sort out the bit you can see along the lines of what CPD is suggesting. As a fudge.. and only when you have little other options. On the back where it may be hidden you can sometimes get out of a hole if the side lap on the slates is too small by using a thinner slate with a code 3 lead soaker underneath.

Hello MonkeyTom. Good options above. Post what width of wall you need to build and the depth from finished ground level to top of found and you should get some more detailed suggestions. Oz07. Don't know if long terms studies have been done but I don't think it's a gimmick as the blocks should have been subject to a freeze thaw test to determine durability before being approved to sell. Aside..if anyone is tempted to buy "seconds" i.e ones going cheep make sure you know why they are cheep and that they are still ok! Fine maybe for a garden shed / green house base but your house? We know for example that air entrained concrete is more resistant to freezing effects as simplistically the air bubbles give space for the ice crystals to grow into. Aircrete block have plenty "bubbles"

Saveasteading. Thanks for posting that and your other info, enjoyable and informative reading for me. Keep going if you can as this type of info, presented in an easy to read format as you have done really adds to the quality of this forum. You give some great practical tips too! Interesting that Steamy Tea mentions carbon fibre and it's behavoir. There are few few posts on BH about folk using bassalt type meshes for crack control in slabs but as it's more elastic " stretchy" athough with a high ultimate strength then many of the old rules of thumb need careful appraisal before swapping say a traditional A142 / 193 mesh out for a carbon derived mesh. You also mentioned slab "curling". I've got a bit of this on my own house. I have a quasie "structural" ground bearing slab.. I'll leave it at that as I was experimenting. I put the day job hat on so cured it properly but I hand batched it so less quality control over the water cement ratio etc..but you have touched on this already. The slab is thin ~ 100mm with A142 mesh and the UF heating pipes are attached to this. It curled before the UF heating went on though. If you give the corners of the slab a "dunt" you can feel it's not fully resting on the perimeter supports at the corners but only by one or two mm so when it cracks the crack width should not be enough to cause a problem for my application. It's not called for example "concrete technology" for a laugh! There is a fair bit to this remarkable mixture as you say. kxi. The joint locations look respectable, the aspect ratio (length of each panel / width of panel < 2.0) looks ok too. I would imagine you have some extra loose rebar diagonally at the corners of the manhole covers as if not you could expect some cracking springing from the corner points of the manholes due to the stress concentration.

Hello TANK. A few thoughts, some explanation which may give you some pointers and another few for all who may be considering knocking down a wall say between their kitchen and dining room in a modern house to form an open plan space. "I'm wanting to install wall piers on my outbuilding as the length is 6m. Asked about this in my original thread but had no response. I wouldn't ask without first doing my own research, but I can't seem to find a definitive answer (maybe 'coz there isn't one!) either by Google or with the likes of you tube. You probably won't as there is a fair bit to it.. "My footings lie around 750mm below where the screed flooring will be. Do the piers always rise with the rest of the wall at the footings, or can they start from the screed (which will be 50mm on top of 50mm insulation atop hardcore.)? The first 5 courses are eng brick which then gives way to thermalite." Normally they rise from the footings. "Im hoping it's the latter as I have overlooked them and will need to do a little remedial work if I'm to go back to the footings... " Yes in the spirit of BH there is always hope and mostly a solution..only available on BH of course.. this can take a leap of faith but here goes with some technical stuff first then a possible solution TANK depending on what other factors come into play on your particular job. The first thing to recognise is that often a wall needs to resist both vertical (from say the weight of a roof or floor) and lateral wind loading.. even internal walls from time to time as you get different wind pressures occurring inside a building. A big set of bifolds accidently left open say on a windy day. Yes folks, we need to "have a look" at this possibility "just in case" to make sure the design is safe. In general terms if you take a brick wall (no big windows!) of say 3.0m long with a good return corner of masonry at each end, built off something solid on the bottom, say a foundation and held in place by a stiff roof at the top then the masonry will "span" in two directions.. a bit like a concrete floor slab that is supported on all four sides, you often see these descibed as a "two way spanning concrete slab". However, partly due to the way the bricks / blocks are shaped/ laid a standard UK masonry wall is stronger in the horizontal spanning direction than the vertical direction. Now at 6.0m horizontally that is a long way for a thin wall to span horizontally so it can resist particularly the wind loading.. you don't get much if any help here in terms of horizontal spanning resistance when you come to check the wall is ok. Also, you need to have a look at how the roof is supported on the wall head as sometimes this can cause an unwanted bending effect just to add to your problems. Very simplistically and just to make a corollary. Think of the wall as a series of two beams.. one goes horizontally, one vertically and they both interact and share some of the load. We "know" that a deep steel beam is often "stronger" than a shallow beam, for example a deep floor joist will often carry more load than a shallow one of the same thickness. The same applies to a masonry wall, the thicker it is then generally the more load it can carry. TANK. At the moment you have a wall with no piers so it's effective thickness is the thickness of the wall assuming it is a single skin. At 6.0m long it's strength is going to come mostly due to it's capacity to span vertically. I think you have recognised that it is probably not quite going to "cut the mustard" especially if you live in a windy area? As a starting point we often say lets put in some piers at 8ft centres ~ 2.4m and see if we can get this to fly. I use imperial units as some of the modern codes still use empirical design to some extent... we know it works! When you put in a pier it often has the effect of increasing the effective thickness of the wall..so in other words you are making the "wall beams" a bit deeper. Now it will carry more load, and this is how you get it all to work as we have made the wall " effectively thicker" by introducing piers. That's the end of the general theory bit! Turning back to TANK's issue. It look like there is no enthusiasm for digging up the floor and building up a pier off the founds. Anyway for a retro fitted pier to properly work it needs to be fully bonded into the wall. Ideally, fully bonded also means that both the pier and the wall should be build at the same time. This is because when you lay mortar you need to "tamp it down" so that the bed is evenly compressed for example and bonded to the masonry above and below the bonded in brick/ block. The bricks, blocks of the pier need really to physically interlock. Some may say.. well use a wall starter kit. Fix it to the wall that is built already and build the pier. This does not work as many starter kits have small coach screws with plugs. The ties also can slip vertically so they do not properly bond a remedial pier to the existing wall.. you may as well use wall paper paste. The reason they don't work is that you get an effect called "complimentary shear" this is a vertical force that occurs between the remedial pier and the existing wall. Wall starter kits typically can't resist this force as the ties move up and down within the profile of the wall starter kit. TANK. What about this? Rather than piers go for some wind posts. These could maybe be timbers (or steels) running vertically from the "structural slab" up to the wall head. What you are doing here is splitting the wall up into small panels.. the lateral wind loading is resisted by the timbers and the timbers also stiffen the wall so it can carry more vertical load. Sounds bizarre but.. timbers are cheep. They will stick out from the wall a bit more than steel but you can use them to support the ends of small shelves? Your floor buildup just says "50mm on top of 50mm insulation atop hardcore.)?" I'll assume you have say a 100 to 150 concrete slab under.. if not then.. ? you may have some serious issues with your floor cracking up and nothing to fix the base of the wind posts to. Assuming you do have a solid structural floor slab to connect into. Here is the lastish bits of the puzzle. The floor (structural slab) will go up and down as the moisture content of the ground changes and the loads on the floor vary (call this the "dumpling under the slab") , the walls hopefully will move not so much as the founds will be deeper. How do you connect a wind post to the slab / dumpling that could move up and down? you use a flexible bracket that is "bendy" https://www.strongtie.co.uk/products/detail/large-reinforced-angle-brackets/265 You can't use these brackets above as the the slotted hole (fixing) is too close to the bottom of the wind post if you go for timber, steel usually ok depending on what the profile is but I posted the link to give you an idea as to what might be a "bendy" type bracket! In the world of design it's ok to sometimes let things bend and recover as steel is elastic..your toilet bowl / floor tiles less so!. So long as you don't go over the score! Now that is a potential solution that will avoid you having to dig a few big holes in the floor to retrofit the piers all the way to the founds. Even if you do you can see that you will have to find a way of properly bonding the pier to the Thermalite. This Thermalite is last elephant in the room.. What you need to do is to find a fixing that will transfer the wind lateral load in the wall to the wind posts. You can often fix brackets to the sides of the timber wind post with square twist nails. You fix the bracket to the Thermalite with an under reamed resin anchor. Attached is the Fischer test report which gives you some pointers as to what fixings can be used in Thermalite blocks, the under reaming drill bits and so on. You can find the drill bits and installation instructions on the web. TANK.. hope this helps. You will probably need an SE to prove this but hopefully it can be a simple process, not too costly compared with BC knocking you back and / or digging up a big bit of the floor in two or three places then making good the DPM and so on. Even if you do this you'll struggle to bond the new pier in effectively and make a good looking job of it. Even if you don't need this retro work for BC then please be safe and get it (the wall) checked out. For all. The above issues often crop up when you want to knock down a wall along say the back of your house to form an open plan room right along the back of the house. Often you end up with a pier / column of masonry sitting in the middle of the external elevation wall . In the old day windows and doors were made of good solid wood / or metal framed and they stabalised the masonry. Now windows are plastic / aluminium framed with "rubbish" brackets that just don't stabalise the masonry up the sides of the window / door opening. Thus often you need some kind of wind post. Normally this is ok and easyish to do but when you encounter Aerated blocks (Thermalite say) or bricks with holes in them the fixings become an issue. That said often there is a solution. All the best TANK. Fischer Test Report for Thermalite_Report(1).pdf

Hello Babak. Please be very careful here. Unfortunately I have seen cases where folk have been a bit too hasty with the demolition and one case where the planners prevented them from rebuilding. There was some other history but it can be that serious! It looks like you have a fair idea of what you want and have a "design" in mind. Also, it looks like you have already put a fair amount of thought into build method, servicing it and so on. What about contacting some SE's? As you are proposing ICF for part of it there are a good few that have a grasp of the fundamentals of this and from their point of view it's often more interesting than just doing the day to day stuff, so they may think.. yes that looks like a project I would like to do. I'll also do the "Architectural side2 and building approval side" as the Client already has a good grasp of what they want and, as I'm drawing it up I'll do the structural calcs as I go along.. it's a very efficient way of doing it! In summary there are a few SE's who also do the whole package, calcs, drawings, a bit of the Architectural design and building approval so don't rule this option out. Even if you don't go this full route there are SE's who will give you a good few pointers and offer their contact base to you. There is a perception that for design you have to first get an Architect.. then an SE.. then a contractor. But all these folk often work and collaborate, learn from each other anyway. So don't rule out approaching an SE, explain what you need. You may get a pleasant surprise as they may say.. well I can do most of it but I know an Architect that can say deal with the parts that are outwith my expertise.

Jilly, thanks for the kind words. much appreciated. The main thing is that it seems like you are marching on now and hey, you probably got a load of stuff done before the material prices went daft due to covid.. so extra bonus to offset the stress. If you look at the cost of doing it now in this climate.. well you may well be in profit already! Jilly makes a good point here for all. If your designer turns round and says this is going to break the budget ask them why. You need to cut them a bit of slack but they should be able to explain to some extent and identify what parts of the job are causing the budget problem. If you just want a house too big for your budget then they should just tell you.. take the rose tinted glasses off folks and here is why.. On refurbs / conversions it's a different ball game and this is where a good designer should be able to identify the areas that are contributing to breaking the budget. Once you know this you can then look at finding a solution. Sometimes it's just not possible to convert say with the money you have, but at least you know why and be in a position to judge if the compromises you need to make may outweigh the benefits.

Hi MdeB I think you're taking a risk. As new build the substrate, founds, what is under the slab ect will still be settling in, adjusting to the ambient moisture regime and possible curing if you have masonry. There will be quite a lot going on under the screed and the supporting structure that you can't predict. The aspect ratio of the screed looks borderline. For a simple concrete ground bearing slab in an extension we consider amongst other things the aspect ratio. Here you have 5.8 / 2.8 = 2.07.. for unreinforced concrete slabs in say an extension once the aspect ratio goes over 2 then it is a flag. For a thin screed.. potential trouble. for slabs we often locate saw joints to control the location of the cracking. I would screed it, saw cut it into three sections 5.8 /3 = 1.93m x 2.8m as soon as it has hardened enough (24 hours) and leave it for as long as you can. Keep the screed covered and wet for at least 7days (preferrably a month!) so it cures, then slowly dry it out. It's a conservatory.. it could be pretty hot.. misstreat the scread and it will return the favour later! Even at these saw cut panel sizes you may still get some hairline cracking unless you are using a screed with polymer / steel fibres in it. Be safe and use a decoupling mat. You don't have to saw it all the way through. If the screed is 60mm thick then saw it to a depth of 40mm. You promote the cracking here as you have weakend the screed. What your are doing is allowing it to crack where you want it to and trying as best you can to limit the size and orientation of each crack. It's important to put a sheet of plastic under the screed so it can slip over the substructure easily as it cures. Get the screed right and the laying of the tiles should be the worry free part. All the best.

Good point here from the_r_sole. It's hard to compare designers prices. You can get a set of BR regs set of drawings and calcs cheeply, but that is all you will get. Just enough to get your approval. You can get them really cheep if you are happy with saying say.. ,x ,y and z will comply with clause x, y and z in the regs.. very few drawings or supporting info required. You'll have your approval but the info you have will be very limited..trouble ahead if you don't have significant experience of building and dealing with individual contractors. It will then be up to you to develop and communicate the detailed design information to the contractors ect who are pricing unless you are really doing it all yourself. The less info you give them generally the more heavy they will be with the pricing pencil or build in caveats to allow them to charge you for "extra work". It will also fall to you to take on the liability / responsibility if you get it wrong, BC come to inspect and say. NO! Put it this way. A good skilled trades person who will also keep you right on a DIY build (maybe by saying.. are you sure you want to do this?) may cost £250 - 300 / day as an average UK price. £31.5 - 37.50 / hour. Now chuck in some plant / van tool costs and so on. Just say 40 quid per hour = £ 1600 per week. That is just for one person. For two.. £ 3200 per week. Now an experienced Architect or designer can easily save you this and more. Go cheep and you risk getting bogged down trying to resolve buildability issues that crop up because you are just relying on the drawings you have use for regs approval, trying to source different materials that will still comply with say the U value requirements and so on. The test when comparing fees is to ask this of the designers. 1/ Your fee is this. It is higher than the others so can you convince me that this extra fee will result in an overall saving..mitigate the fee? Tell me how you are going to do this. Explain to me how say you have thought through the buildability aspects so it's easy for local trades persons to build and thus they will be less heavy with the pricing. Are you sure that the materials can be easily sourced and on time to avoid delay on site? Where is the risk in this project to me, can you tell me where the risk lies so I can make an informed descision? A good designer will think about all these things but that "thinking time" and experience comes at an upfront cost. 2/ Your fee is this. It is the lowest! Can you convince me that I'm still going to get the same service and effort of design thought on my build/ project? Can you assure me that you are giving me enough information so that a contractor is not going to get free access to my bank account while at the same time my job is not going to go off progamme, I'm not going to get into trouble by inadvertantly by doing something that may breach the regs.. go for the completion certificate and get knocked back.. ? If your designers don't like these types of questions then.. keep looking. As a last thought.. a washing machine repair "Engineer" may cost £ 60 per hour.. this is your home. While the professional fees may seem a bit steep initially, once you look at this in the round and if you don't have significant experience then a responsive and supportive designer can be a good route to follow.

Ah! Preparation is the key in my view. Clean off all loose debris, loose mortar at the wall heads and so on, even give it a hoover. This way you'll be less tempted to over spray. You save on fluid and this will maybe tempt you to spend more on the chemical spray. Long lances? well you'll get the easy to reach bits that are drafty but the worms etc will seek out the parts your "Heinekin" delivered "blind" from below has not reached. If you want to do a good job and are just not looking for the paperwork then set up some proper access and do it thoroughly. Not sure on costs but you could sequence the works so that you can use the access platform for something else at the same time, say if you need to cut out and splice the badly wrotten rafters?