Gus Potter

In the spirit of BH... you may need to offer up a bit more than an apology! maybe an "abject apology".. or a bottle of something in the post!

Hiya @LaCurandera "Kitchen in the "new" 60s extension - good idea which I'll explore. There are services over that side (currently there's a bathroom roughly where the snug is) although boiler isn't. One consideration is that we are unlikely to go back further in that corner (where office is) as that's right on the boundary already and possibly much extra would be within 45' of a rear window of next door. Hence stepping in the extension. So we'd be taking out that left side wall where the stairs might go up which is internal now, but originally external. I'd tried to work with as many currently walls downstairs being unmodified (or at most doors filled in etc). Maybe being a bit braver would be good, although presumably costly. " Don't get too hung up on the services for now, keep an eye on the where the electricity comes in though as shifting this can be an issue. Good point about the boundary issues, daylight and over shaddowing. You also have fire protection.. fire boundary conditions. I would get an SE on board that your Archtectural designer has a relationship with. The SE will just keep a watching brief and give the Architect pointers as to where a small layout can be changed if need be that will save a fortune / bring the job within you budget. Remember that this design is going to be an iterative process. To avoid wasted time and expense get the design team you need together early and let them bed in.. and get to know what you really want out of this house as you live in it over the coming years.

As always Steamy you are spot on! and elegant points made. For all, hope this helps the keen tecky. Take a timber floor joist, or a ruler at home. Support it at each end an apply a load in the middle. The ruler bends down so the top shortens and is in compression, the bottom stretches so is in tension. Masonry ( brick walls) are not good at resisting tension.. so if you add enough load to the top of the wall then the masonry never gets to the tension stage. Steamy is spot on.. this is the one of the basic basic concepts of prestressed concrete design. Steamy mentions what is called "buckling".. again correct. Put the ruler on it end and push down from the top. Suddenly it will give way.. this is a buckiling phenomena.. Euler circa 1700's the mathematiccian developed the theory behind this and is a fundamental principle underpinning what SE's do today. So yes Steamy, if you add to much load you risk buckling.

Grian.. remember if you make something like this fly, enjoy building it and make some money then you got a leg up from BH.. so a small donation to BH would oil the works! I do think that if you have a local joiner on hand you could build a safe structure for holiday accomodation out of timber frame for not a massive outlay. You could almost have detachable cladding.. in effect the structural TF sits there and the outside cladding acts as a rain screen.. could be just recycled pallet wood at the very basic. As this is a temporary moveable structure not a house that you get a mortgage on that has a life expenctancy of 60 years you can afford to change the cladding and appearance if you wanted to suit you target market. I don't know where you are but the saw mills do some real rough but cheep timber off the outside of the log that can be used for cheep rain screening. You could use all sorts of material depending on what visual impression you want to give out.. I love this stuff. You could have great fun exploring what you can do and how you tailor the appearance to your intended holidaymaker market. My sister has a B & B on Tiree so the market there is split between commercial clients coming to serve the radio mast, fix the fridges in the coop ect and at the other end folk going for a holiday that want to stay in a nice place. Keep posting!

Thanks @SteamyTea Much appreciated. Inverted roofs are something not much touched on on BH. More commonly you see them on larger refurbishment development and commercial stuff. They do have their issues but this for something like what @Grian wants to do on a limited budget while mitigating the financial risk, the constraints i.e moveable.. it could be an elegant, cost effective and environmentally positive solution. On the technical side I mentioned TF. You can increase the stiffness of a TF panel (thus better able to resist the sideways wind loading) by adding compression from above so the slabs perform this function.. it's all about getting the different elements of these small light weight buildings to do more than one job.. you look to get your pound of flesh out of them. Yes in a windy spot you will probably still need to tie down with cables for a bit of robustnees but the in the round I think this is worth a look at concept wise.

@LaCurandera Well done, colour coding can be really helpful. Persevre with the gridlines if you can, it will pay divdends later when you get further down the road when you get your Architect on board etc. Also, well done for making a start on the layout.. if it's not your day job it's a often ahard .. and even if it is your day job.. it can be challenging (but enjoyable) to come up with a good concept. On the layout my first impression is that I would want to explore shifting the utility, and GF bathroom to where the snug is.. that is the "working part of the house". I like your idea where you come in the front door and you get a line of sight right through into the back garden. Much will depend on the aspect of the house and where the sun rises and sets etc. To get the best out of Bh also mark how your plans sit relative to North.. there are some real innovative folk on BH. I see you have a big landing up stairs, but a modest stair case. When you come in the front door you almost enter a corridor.. I would look / explore to make the rooms upstairs bigger, reduce the upper landing size and spend the money creating more of a wow factor as you come in the front door. On practical point .. sounds great having a bathroom close to the main entrance.. but..! If you like the idea of a "grand entrance, upper landing then you can sometimes achieve the same effect but the use of a roof lantern and some well placed mirrors to create the same effect while increasing the usable space in the rooms. All the best and keep posting.

I would go ahead and get the MVHR up and running. If you compare the cost of your flooring cf regular replacement filters then.. if the flooring goes wonky then.. big disappointment. It's also all the other finishes such as doors, facings, say you kitchen cabinets etc.. start "breaking" them in now and if issues arise it's easier to address now than later?

Hiya @LaCurandera Interesting project. To get some structural feed back it can help a lot if you put some gridlines on the drawings. Put a grid over the new layout and transfer onto the old. Now you can easily see where the old walls and founds below relate to the new. Sometimes when you want to put an extra storey on you find the old founds can't quite take the increased load. Before you throw in the towel you look to see if it's possible to spread the load out a bit and make the internal walls carry a bit more. Also, if you can put a grid on it make it easier to refer to when making comment on the Architectural design.

Hello Grian. You could have great fun with this. I've been lucky enough to have dabled in this on the structures side on and off over the years; light weight cold formed steel / TFstructures, high end man caves etc, it's enjoyable. In terms of proving it is "movable" then if you made the main section no wider than 2.9m then this would fit on the back of a low loader without being classed as an abnormal load as I understand? I wonder if you could also build it with extra modules, like those mobile homes that once parked the sides extend out. This would allow you to detach the side modules. Yes, you would need more trips to shift it you started with two modules that are a similar size to a 40 container you could then add bits to provide an improved layout, less corridor and more living space? In terms of how you build something like this.. it looks like you are near a sea loch. I would explore doing it as a TF. You could do it as metal stud ..dry wall idea or thicker cold formed steel sections both with limited life expectancy but TF is more suited to a local builder, (or say a joiner) and more survivable in a marine type environment as it does not corrode. Also, easier to insulate. You could almost panelise it so rather than transporting the modules you diassemble and transport it flat pack style, like a fully serviced module construction. Ideally you want to see if you can keep some residual value in it in case you later want to flog it (to say a self builder here as temporary accommodation! and do something else.. at least any residual value should cover the cost of getting rid of it or upgrading? I'm not a guru on the caravan regs but as I understand it so long as the structure is capable of being moved from one place to another then you are on the right lines. I don't think it's a massive engineering challenge to do TF modules that you shove lifting beams under and crane onto a low loader. If flat pack then four folk can man handle them on and stack. In terms of structural wind loading with a bit of thought you can design and build a strong TF easily capable of standing up in the wind. The big thing is you need it to be light weight so you can man handle it.. but then it wants to fly away in the wind! Also for simplicity and to keep the cost down you probably want to put a flat roof on it.. which is hard to insulate and ventilate. But.. the roof can be an inverted warm roof. Here you have a roof as follows;.. could be exposed timber on the underside (saves the cost of the ceiling) , then say 18mm marine ply, the water proof layer (say EPDM single ply membrane a pondliner almost), then the insulation and say paving slabs on top. The paving slabs act as the sound proofing so folk don't get woken up with the hail, the rain and birds tramping about on the roof at 5.00 am in the summer. The slabs also help act as ballast to stop the whole thing lifting in the wind and the insulation flying away. When you want to move it you take off the slabs, recycle.. either flog the insulation or recycle.

If it was my wall.. which of course it's not I would hack off the render and give the stone a wire brush. Then leave it for a year. Provided it's not holding back something that could, if it moves, pose a safety risk or fall on someone. During that time see where water seeps out, if it does. When you have time, investigate behind the wall to see if there is some drainage too. Then once you have worked out what is going on behind the wall you can then decide whether to point or render and where you maybe need to install weep holes. The render at the moment is probably doing more harm than good. Re rendering with mesh or not, lime based mix or cement.. is just kicking the can down the road.. and could be a waste of time and money. Take the render off and let the wall breath and relax!

Good stuff. Sit down with your SE and look at your options now you are starting to get a feel for the cost. From time to time having to value Engineer can throw up other design options you may have not considered before. You may get a pleasant surpirse and save some money along the way. If you want post some cross sections so we can see the shape of the roof etc. Good luck.

Plus One

Yes I read it that way, the intent is to decouple to protect the ceiling. The term sistering can be interpreted in different ways... then the different types of connections take on a life of their own! All good fun though. Converting lofts can be quite a challenge! .. but satisfying. Simplysimon has great point. This can be done provided you have the height to play with in the loft. It can work structurally but here is the rub. While you can as a designer can prove it all works and produce a specification, in real life unless you know the Client is going to need to have you supervise the work on a daily basis as the chances of a builder doing it properly are low.. and that is a safety risk. Thus I often avoid this elegant and economic approach for safety reasons on domestic projects. I do have a pal that wants to convert his attic and this is something we will look at as I know he will be absolutely dilligent and do it correctly. The secret and elegance in Simplysimon's potential solution lies in the concept that the screws only provide the compression of the longitudinal joint while the glue cures. After that the screws become essentailly redundant. For the glue to work the faces of the timber need to be a little rough, flat for a good mating surface and absolutely clean. The glue needs to be a structural glue such as Cascamite two part resin. What we do (and now have) is to create a 2 ply glulam beam and use the same analysis techniques.

Jenki Lot's to look forward to. Looks like you are pretty close to the sea so check the plastisol specification regarding corrosion near the sea and where you stand on that re cladding warranty on the pods. All the best.

And really difficult to get off tools and all the other unwanted places it seems to get! Good idea by the way for Onoffs flints.

Let us know if you try the SBR. Worth a shot I say.

I suppose it's a question of terminology. Some folk think that sistering means doubling up the joists and connecting the two together along their length so you create a joist twice the thickness of the original one out of two bits of timber coupled (bolted say) together (the old and the new).. thus roughly you can double the load without a bad outcome. But remember that the old timber will have creeped a bit and seasoned so will probably pick up a bit more load first before the new "bendy" timber starts to pull it's weight. Something to consider if you have a period ceiling below. Or sistering can maybe interpreted as adding another joist in between the existing? making it a bit higher and thus you create a floating floor..have done this where you really decouple the new floor / attic loads from a ceiling that is sensitive, say an ornate ceiling. There is quite a lot to think about when doing loft conversions. Often you don't want to mess with the floor / ceiling below as you are living there. Now a plasterboard ceiling often has dwangs / noggins so to sister (doubling up) you need to cut them, to get your new timbers in at the same depth as the existing joists.. and refix the dwangs / noggins. A bit of a guddle (faffing about) = £cost. Often you find that there are cables, a few pipes etc and to keep the cost down it's helpful not to have to move them, especially over the consumer board area if a lot of cables run up into the loft. A lathe and plaster ceiling relies a lot on the plaster squeezing up between the lathes and expanding (belling out) to create a mechanical key. Call these the snotters. Would be interested to hear what the local term is in different parts of the UK. If you knock them off then the plaster will become loose , particularly as the timber lathes will have shrunk over time. Often it's best to have a look at what you have early on; can you move out, do you have period features etc and then see how you do it structurally to accommodate the constriants.

Yes I was expecting a huge hike in my PI as a sole practitioner. Couple of drivers were.. a lot of folk are not making a good job of basement and swimming pool design and the big thing is the cladding / fire. As a guide an SE sole practitioner can get £2.0 million cover for under 2.0k a year with 5 years no claims provided you stay clear of swimming pools, tricky basements (deep ones) and fill in the forms correctly regarding the maximum height of building you are tackling and where you lay off the liability in terms of cladding design. Now you probably don't need that level of cover if you avoid the SE side. I would hope that you could get PI for 1 -1.5 K maybe a bit less? for say 500 K cover given that your are a Chartered Architect. Now in reality to work on your own and starting out you generally need the bread and butter work. The garage conversions, extensions and the like. Commercially you spread the risk of getting hit with a dodgy Client that refuses to pay.. all your eggs are not in the one basket and you can afford to take a hit / fight it out while still making a wage. Do a good job and you'll find these bad clients are few and far between.. but get the odd bag egg who owes you a lot and it scunners you. You could go for the high value jobs and only need one or two a year.. but the cash flow.. getting used to working for your self, worrying about getting bumped.. Also if you only do a few jobs a year you don't get your name about that much. Remember that if you do a job for a young go ahead couple they will then often get the bug, move to a larger house and phone you while recommending you to their friends.. On the upside these small jobs can be very technically challenging.You can be highly creative as to how you design so it's not boring. These small jobs can be a real test of a designers skill. Once you get up and running, or now, try and seek out some young keen, intelligent, dilligent small local builders that have a future.. make yourself the go to Architect and as their business grows so will yours.

@CharlieKLP Good thread this and you are holding your own! I'm sure you will do well and enjoy your journey. On small jobs, say extensions and the like I don't provide the CAD files to a Client unless it's been agreed at the outset. I do though share my files with Architects and others that I know and trust not to do anything daft with them. They are shared as uncontrolled files and this arrangement works both ways. I often say when you let folk see the cad file it let's them see into your sole, it's you own personal work space. When making formal issue of a cad file I strip out any IP that is not associated with the job as yes you don't know where it will end up. But doing this when collaborating with folk you trust and have worked with is just sending out a message that you don't trust them! Yes you clean things up a bit so they can comprehend what they are seeing but often I splatter notes and my thoughts on the cad file so folk (and myself later ) can see what I'm thinking and where we need to go with the design. Once you get to a certain stage the design is frozen and so is the cad file. If issue is required. Food for thought. lets say you have a new build with lots of steel / industrial building. You have a set of pdf drawings but on larger jobs to give your Client a wide range of options you also provide a numerical control file called an NC file that the fabricator loads up straight to the machines. This is a text file, hopefully @Onoff and the like can fill in on the detail. Now the text file is just like a cad file in some ways... the lines start to get blurred here?

I use cold formed C sections from time to time. Couple of examples. One was loft conversion with rear dormer was really tight for height. Could not go above the ridge line and had to maintain 2.0m ceiling height on the inside. Eventually after exploring a good few options I plumped for a 140mm deep cold formed cee section with insulation on top.. a warm roof so the steel is within the the insulation envelope thus avoiding many condensation issues. In many ways it was the geometry of the conversion that forced this solution, tricky connection details, other ventilation issues and these kept closing down the more convensional solutions you see on many attic conversions. Another example.. Client requirement to minimise disruption to the floor below and maximise attic floor to ceiling height. Need to span some 5.0m with some relatively big point loads from dormers.. and the structural walls below are all in the wrong place. The existing attic joists are 200mm deep with lath and plaster ceilings.. that must be kept intact.. no cracking! The existing attic joists are supported by transfer beams mid span. See some posts on BH where the roofs have a purlin supporting the rafters. The transfer beam is just like the purlin but at attic floor level. The problem is that this transfer beam has to go as if not it will end up in the middle of the new floor. To overcome this shallower back to back cold formed Cee sections between the existing joists to span the 5.0m are introduced. This works well as the cee sections clear the lath and plaster and leave room to run electric cables and small bore pipes. Also, as the walls below are not in the right position the cees in places function as cantilevers. Now this all sounds awfully complicated but it's not. The sections are straight out of say the Albion / Steadmans brochure. One key here is also to use their standard punching pattern for bolting. Remember that these sections are used by the kilometer in industrial buildings all the time. One thing though is that you have to do your own calcs for these when say using them as cantilvers and off piste applications.. and the calcs can be very lengthy and time consuming unless you are familiar with cold formed steel design. Lastly to get the best out of you local builder it's good to provide the fabrication drawings for your cold formed sections in say the Steadmans / Albion , other formats. All the builder has to do is then send the drawings to the supplier. This is standard practice in the industrial sector. Often a local builder who just does say extensions is less familiar with cold formed steel in these applications , but if you hold their hand a bit they often engage. @Annker Keep exploring this as on option, even if to rule out at the end of the day.

Take a bit of time to digest and go back and read the other comments again from BH members. Play about on BH and read around, you'll pick up some great nuggets for later anyway. Then take a view on whether getting an SE feels right for you. I'm not strong on spelling either and get carried away as it's social media! Folk don't pay enough for a desk top study in general.. they see it as a box ticking excercise so they get what they pay for from the professionals. Nowadays professionals just provide a churn that looks good often with little value and try not to accept liability. It's a mess. No wonder there are reports floating about exploring why UK build costs are apparently high. I've done a few desktop studies and a good one takes time.. some several days / weeks to gather the info and then a day /s or so and a night/s to sleep on it. This approach has saved some Client a fortune that has well out weighed the cost of the study and mitigated the cost of the on site ground investigation.. The really hard part is to convince a Client that what you are doing is worth while! You can do an lot to help yourself here. I would put your back into it and do you own research, it's only your own time you are spending. I clicked on the link for the desk top study but for some reason it is not downloading? can anyone help?

Be careful what you wish for! Firstly thanks to all for all your posts have enjoyed reading them, there are many to thank but @the_r_sole is a font of knowledge who gives it to you straight up as are many others. Charlie.. it's very much doable. A few years back I embarked on a similar journey although I came at it from the SE / Contractor side. While I do my own design stuff and some "Architectural Design" I collaborate with in particular with one really experienced Architect. I have said to him in the past.. you don't need me (SE hat on) as your design is spot on. He just sizes the building / structural envelope and main beams say nearly always correctly, but he has been doing it for nearly fifty years! But then we start to play about. I put my Architectural hat on and he puts his SE hat on.. we are like "two old grumpy men" and the result is some elegant, competant, safe, and economic design. Oh.. I use the word elegant as this indicates that it will stand the test of time. The work is flooding in and a lot of it is repeat business coupled with some interesting stuff. So yes you want to do your own thing but find some one that can compliment your skills and recognise that you can feed off each other and learn new stuff... together. I advocate that a great Architect should also be competant in structural design, not the calculations but have to a feeling for how the building works and that includes how it stays up structrally. A great SE should be at a minimum competant in the principles of Architecture and have a bit of flair / artistic bent. Over the last few decades the professions (Architects, QS' SE's etc) have diversified and you can see this on BH.. no one is talking to each other and the Client is left in the dark. From my own recent experience I have found that going back to the "old way" where we all start really working together pays dividends. Yes there are a few Clients, BH members too that think it still pays to breakdown each design element to get the lowest price. The lowest price is not always the best in the round. See Ruskin common law of business.

Hello Zak. The thing I enjoy about BH is that you can chew the fat without getting your head bitten off. Have copied and pasted you text in italic with my comments/ fat! "Does this mean given its currenlty a banglow I will be limited to banglow (no build upward) option unless I go down the underpinning option which is a not an option at the moment." No. what we look to do is to see how we can redistribute the loads to "trick the ground" into thinking that nothing has changed too much and then we design for the little extra anticipated settlement.. yes my name is Potter but not Harry Potter, but do wear glasses. So I had two full bore holes and third extended via with dynamic probe with two trial pits as marked on the plan. If I need to do more trial holes I would need to get ot sorted via a professional but what is it I am looking for which could not be done previously. Sorry just trying to clarify my understanding. You need to take a few steps back and look at what you have on site, you just missed the earlier steps? maybe call these earlier steps a walk over site study, preceeded by a desktop study. But unless you do this all the time then you probably won't know this. Don't worry though, your GI is of much value. I don't think you have done anything wrong, maybe just got the order / sequence mixed up? I would put together a little "portfolio" on your project. A summary of how you came by the property, what you know about it, what you have done say planning wise, your research and so on. Include a title plan, the sort of things that show you have done your best to get as far as you can. Then a short bit on what you want your project to deliver, make it personal. Take that to a few local SE's and ask them if they can help. Don't mention fee cost at this stage. SE's know this is coming down the pipe anyway. You may well get a pleasant surprise and an SE will drop into your lap, pick up the ball and you can work away together finding the right solution for you. You have an interesting project here that is technically challenging and there are plenty SE's that love this kind of stuff.. provided they get renumerated at a fair rate. In return they will often seek to mitigate their fee by saving you money. So that is 4tonne per sqm. Would this be enough for a banglow only or traditional block and brick two and half (loft) storey house? At 40kN/m^2 ball park you could achieve two storeys plus the loft. Just don't be gready with huge spans, beam and block for serious acoustics. You can still create a great family working home future proofed. The trick here is to get an SE in early and they can work with you to support the Architectural design, which will help avoid you going down blind alleys and racking up design cost. Definitely, I would consider that if it's possible and a cost effective solution. I had a chat with Hilliard Tanner (Ireland) as @joe90 suggested and he was to going to look at it but he mention thin steel cases concrete beam with raft ok top among one option so I am keeping fingers crossed. By all means talk to Tanners but you may want to consider a local SE that also has a black book of local contacts, brickies, sparks etc and reliable local folk.. and hypothetically a really black book of who to avoid locally contractor wise, not that they do keep such a book as this may be illegal. In terms of insulated rafts you may see insulation load bearing values of 130 - 150kPa (150 kN/m^2) at 10% compression but put this in at 250 -300 mm thick and it will squash a lot 25 -30mm.. too much. Now what SE's look at is what can the building tolerate.. say 10mm as this has to be added to any ground movement. We look at the load bearing value at say 1 -2% compression and now were are down to a bearing capacity much closer if not less than the 40kN/m^2 I have been mentioning.

Hello @CharlieKLP Been lurking following this thread. I'm a designer with a penchant for structures. If you can hold your own on Build Hub then your future is bright! Wishing you all the best and will post a bit later on my experience for your to pick over.

@Zak S Za.. an after thought. When you are comparing piling quotes check what they require in terms of you preparing the site, access you may see mention of a piling matt. Much will depend on the size of the rig and pile type. Often they will say you need to have the site preped up to X,Y,Z talk about making it hard to compare quotes.