Leaderboard

Hello, Another post and another year of self building. Since my last entry we have made some progress in a few areas. I previously mentioned some trouble that I had with the treatment tank. We choose a Tricel model as it is widely installed on Skye and the local merchants all suggested it. The alternative was a rotating one with moving parts which I was keen to avoid. Other models were getting costly to be delivered and would require some form of mechanical unloading at my end. After my post I had a fair bit of communication with the manufacturer and the merchant. I didn’t back down and didn’t pay, in the end they backed down and sent a replacement. This went via Inverness and the merchant wanted to inspect before delivering to Skye, guess what they found? Three tanks later and it’s now in the ground. Discharge will be to a ditch, which at this time of year is wet but for most of the year is usually dry, this runs off to a wooded area at the bottom of the croft. Our original warrant and SEPA approval was for a traditional septic tank and soakaway (amended installation was agreed with both parties). After some posts on BH it was clear that a treatment tank would be the better option all around. I should say that a traditional septic tank and soakway is still quite popular in the Hebrides, two recent self builds both installed this set-up. Whilst the digger was here, we decided to get some further work done. A gravel drain was put around the back and is working well. Rotten rock which was at the front of the house was used to bring up the level around the house. A big pile of clay and top soil (or mud mountain as some called it ?) from works back in 2015 was then landscaped around the site. We are pleased with how the house sits in its surroundings. Finally, here is one from the Broch. People have been self building here since the Iron Age! Although this one is down to foundation level with the rock reused multiple times in various self builds during the last two thousand years. We now need to put the fence back up around the site to allow our sheep to come back on the croft. Today’s job has been digging and fitting four posts. The electricity connection was moved from the temporary supply box into the house. The cost for this work was cheap at around £200 and done by two very tidy and polite SSE workers. This simple homemade box was constructed from scraps and has lasted four long Hebridean winters but will now be recycled for another purpose. Talking of recycling, I don’t have a skip on site and everything apart from dust is stored and will be used for another job. Internally all our efforts have been on the upstairs of the house. Upstairs is an easy win to get completed as it’s just our two children’s bedrooms and an upstairs living area. A bit of time has been spent with our MDF skirtings, architraves and cills. We used real wood in our last build project and it has moved slightly over the years, MDF won’t do this and is cheap, but requires work in sanding and painting. Carpets are due to be fitted at the start of January and once these are down it will just be electrical sockets, lights etc to finish the rooms. Internal decorating can then commence downstairs. That’s about it, the kitchen has been fitted and downstairs flooring is done but both are covered by copious amounts of cardboard and I’ll upload some photos once this is removed. Thanks for reading. This will be the last post for 2019, hope everybody has a great Christmas and best wishes for your projects in the New Year!

Have a look at this sort of place https://www.dreamdoors.co.uk/kitchens/doors

Stunning!!!

It’s not so much that they won’t let you It’s ideally ground conditions Mine being lots of trees What you need to consider is with BB you will have to add a screed afterwards Where as with a slab you can usually tile or floor straight on top

You don't have to be cynical to get that this is exactly what will happen because the profit motive will drive it - something like this... "Which charge option would Sir / Madam like, we have the always full model where you pay a small monthly premium on your standing charge and a charge anytime rate, for your connection so that we allow you to charge your car anytime and we never use it for load balancing OR you can have the hope it will be all right where we can stop your car charging if the grid is overloaded you pay slightly less for the electricity you do get but we cannot be sure you will get it all the time" as we, he says under his breath, can charge people on rate the always full tariff more for it." The alternative, where the power of the consumer really comes into play, so when he grid is suffering the DNO gets into a bargaining position with you about how much they will pay you to flatten your battery - imagine the trading algorithms, won't be allowed so you can forget that. Better off building yourself a power station and doing your own thing - suddenly off grid becomes more attractive if you can generate it and store it.

@Russdl I know this was 18mths ago, but I was just looking at exactly his in our PHPP model, and I think I can see your issue. It seems you modelled a single stud wall with 300mm of timber at 600mm centers, rather than a twin-stud wall. The 6.4% applies to the two 89mm sections, but not the 122mm section. The 122mm section does have some timber (the noggins with nail plates), but its a lot less than 6.4% I beleive. I'm not sure if this brings it down to 1.2, but certainly not as high as 1.37. I was a bit concerned when seeing your 0.137 intially, as I know MBC use a "foil/membrane" product in their u-value calculation for their closed-panel/PIR system which has (I'm told) a questionable impact their u-values, giving an advertised 0.14 with the foil vs. closer to 0.18 without the foil! Based on @Jeremy Harris's numbers, and assuming his external cladding isn't particulalry insulating, it would seem this isn't the case with the 300mm sytem though, I hope so anyway! Dan

Progress on site has been a bit slow so we have combined the last two weeks together, and also the guys packed up early on Friday for their long and well earned Christmas break. Over the last two weeks you can see them taking down the last of the shuttering and getting it off site. So that is the end of the poured concrete for us which is a big milestone and you can now see the full extent of the basement / foundations. The next step was to put a fillet of mortar all around the outside of the kicker to get a smooth edge for the membrane, and then prime the outside of the concrete in black. Then they have started to put on the external tanking membrane which has been a real challenge in the wet and cold. At one point they resorted to putting the membrane in the digger cab and running the heater to get it flexible and warm. They managed to get the left hand side wall completed and the first job next year will be to put the French drain around that side and backfill with clean stone so they can get around to the back and continue the tanking. They then need to build the internal walls out of blockwork and then the beam and block floor ready for the Timber Frame. So given a really wet autumn progress is pretty good; the guys have worked really hard and though it has taken longer than we thought, we are pretty happy. Now it all depends on the weather in January! The waterproofing guys inspected the concrete and declared it 'near perfect' so looking good for the warranty. Also the BCO and Structural Warranty folks all seem happy so that is comforting. They seem impressed, as we are, with the quality of the work and the attention to detail - which, given the weather, is a huge credit to the guys on site. And whatever the weather they are cheerful and work really hard. Are there any convention out there on how you treat your contractors? - we make sure to drop off cake or cookies to them about once a week, and even mince pies for Christmas! It also looks like we have finally got some drawings to sign off from the TF company so just waiting on our SE to agree and we can push the button to get it into production - so likely to see it in Feb. Similarly with the windows - we have a complete schedule that looks good and though it has taken ages the window supplier, the TF supplier and our Architect all see to be in agreement - fingers crossed they all fit!!!! And they are on 12 - 14 weeks lead time so likely in March! So wishing all of you following our build a Happy Christmas and we are looking forward to further progress and an exciting New Year! On the video front see https://www.dropbox.com/sh/th9f6e3cel5dm1q/AAAfsWdAH184J75bCNUUtzVra?dl=0 for the weekly videos (Week 12 & Week 13 just added - but not too exciting). And as an extra special Christmas treat the entire 13 weeks of 2019 Groundworks videos are compacted down to a 3 minute video summary named 2019 ( https://www.dropbox.com/s/jbvjhdxn1dyrufm/2019.mp4?dl=0 ) Its much too quick to capture the detail but it give a really rapid view of the progress we have made this year - starting after the demolition in October. So still a way to go - but moving forward is so much better than having your soul ever so slowly destroyed by the Planning process! So From This To This

Greetings I am in the early stages of building a single storey oak framed outbuilding around 90m2. I intend to do everything myself to keep the cost down and as I have always wanted to build a cruck frame, indulge and try and enjoy the process. The ground has some clay content and is close to trees so I was thinking about going down the route of an insulated slab which doubles up as the envelope to form the raft. You may be familiar with passive house foundation stuff. The problem that I am finding is that despite being ‘just a large shed’, building control will need to be satisfied that structural calculations are done. To this end I have had some some quotes done and most are eye watering, or reasonable with the proviso I then spend a small fortune on a bespoke polystyrene system. Is anyone aware of any generic calcs for rafts (after all there are tables for timber beams!). Any help of any kind would be very welcome Cain assembly.pdf

I'm afraid I really struggle to see any advantage in using beam and block. Thermally, it's poor, as no matter how much insulation you install, there is always going to be a higher heat loss than a ground bearing slab with the same insulation, just because the air in the undercroft will be cold in cold weather, colder than the ground by a fair amount. What's the rational behind anyone using beam and block, as I'm genuinely puzzled?

just done my b&b floor, wouldn't do it again. expensive and quite a bit of deflection, live and learn. section IE has thermaliteblocks and IF has marmox. TBH i wouldn't bother with either as @ProDave says, make it simple - lay a slab.

But you don't need to spend a fortune to get a good quality build. It's all in the detail. Mine is most definitely not a high end deluxe build, it's just done right with lots of time and effort put in to get it that way. To get a house that barely passes building regs and comes in at a c rating won't require vast loads of money and time to get it to a B and even possibly an A with the addition of some pv. What score you get in the air tightness test will be a massive indicator of how your build has went. How are you sealing up the inside skin of blockwork?? At all the junctions, floor to wall, wall to ceiling, wall to Windows/doors how do you plan to sort these out?? Will your Windows have trickle vents and will your front door have a letter box?? Are you going to seal up every conduit in the house plus around all sockets and ceiling lights??? All that's above is what is the difference between a mass built house and what you hope to end up with. Not one care is given towards these. Dot and Dab plasterboard is used so you end up with a thermal tent. If you're lucky you get scrim cloth at the ceiling junction but as your house dries and and moves it cracks and then any heat escapes. You won't have anything at the window door junctions. All conduits and service pipes won't be properly sealed up. Not one of these issues will cost a fortune to remedy but each will have a massive impact on how you're house performs.

I currently have a build that is “standard” construction but has a target top B rating (not putting solar on to get an A) that is traditional build. Total cost to date - including £8k kitchen - is coming in at £775/sqm. It’s not deluxe, it’s standard construction, but it’s about attention to detail. Floor is 150mm PIR, walls are 150mm blown bead with some areas 25mm overboard, roof is 200mm Earthwool with 25mm or 50mm overboarding. All glazing is triple glaze uPVC. Airtightness is plastic membrane, foil taped joints on all PIR internally. MVHR is a commercial Mitsubishi unit, heating is UFH and ASHP. My - and the clients - notion of spending close to £1m is to get something that actually meets specification. It’s not to do with practices, it’s to do with getting what you paid for..! The reason I don’t like B&B is that unless it’s for specific ground conditions, it is more expensive and labour intensive than a ground bearing slab. The reason a lot of house builders use it is that they also don’t need to remove as much top surface generally with B&B so their muck away costs are less. On individual builds, a single slab of concrete with the UFH built in is cheaper and more effective as it is also dry enough to finish long before the end of the build unlike screeds that can need force drying. Most mainstream builders see UFH as the plumbers job and they aren’t on site until the shell is up and watertight as all underground services are completed by the groundwork teams. Having a plumber into a site for 1-2 days to fit UFH at ground works level would not be easy or cheap to schedule - hence why B&B at groundwork level followed by insulation pipe and screed at first fix is the norm. As you're building a single build you don’t need to follow this and tbh you can get a better finish for the same money the big boys play at per plot if you work hard however you need to save on the fabric where possible and work out the best way to maximize spend. Cost vs Time is the only equation a self builder really needs to focus on, quality should never be compromised.

We're finally at the point were we've reached one of my most concerning details of our build (so far): the footing between the timber frame and the foundations! As some of you know, we're going for an MBC frame but are unable to make use of their slab due to the clay on our slot mandating a suspended foundation! Hence we're going for a beam and block setup, but have been concerned regarding thermal bridging. This is what our architect has suggested, and I'm curious as to what you all think! You can see that our 300mm wide twin-stud TF (cellulose insulation) will rest at least 150mm above ground level on brick externally and low density block internally. Key component will a single course of foamglass blocks (such as Marmox Thermoblock, Purenit or Compacfoam) to reduce the thermal bridging. We’ll also add in XPS insulation between the structural supports and also a small amount of insulation (undecided what type, rockwool?) overlapping the TF and structural blocks along the inner wall. About 200mm of EPS insulation will go down on-top of the beam-and-block foundation with a 100mm screed floor on top of that. I've seen similar alternatives suggested, such as Touchwood Homes method that @bissoejosh suggested and others in the thread below which appear simpler than the above. Are we over-doing it potentially?

- here are several possible options foamglas - https://uk.foamglas.com/en-gb/applications/foamglas-perinsul marmox thermoblock - http://www.marmox.co.uk/products/thermoblock purenit - http://en.puren.com/fileadmin/user_upload/products/industrie/purenit/en/Purenit_ENGLISCH_2016_SCREEN.pdf compacfoam - http://www.compacfoam.com/26-compressive-strength.html - none are exactly cheap though.

I'm having a beam and block floor on the ground floor (apart from the garage) and this is my floor makeup from top down: 75mm screed 500 gauge vapour barrier 75mm Celotex FF4000 150mm Celotex XR4000 1200 gauge visqueen radon barrier/dpm on blinding sand 150-225mm beam and 100mm Celcon blocks. My question is can I replace the Celcon blocks with an insulated block like Tetris or Jetfloor (or the beam suppliers own thermal block) but keep the other layers, so I'm basically increasing the floor insulation? I've yet to price it up but wondered if it's a good idea or will the difference be negligible? Cheers Vijay