Thorfun

the groundworker made a mistake with the size of the insulated slab for our entrance hall porch. the design is for a 200mm EPS300 raft that joins with the basement walls as follows (hopefully it makes sense): the green bit in the screenshot above. We measured it out but the mistake is that he thought the measurements we did were to the outside of the slab but they were to the outside of the 100mm insulation and so I am left with 100mm on either side that is now a cold bridge. hopefully the photos below show what I mean with the blue areas in spray paint being the timber walls that should sit just over the insulation. the slab has 2 layers of A393 mesh in them which is supposed to have the usual 50mm cover at the sides and is 200mm thick. potential solutions: 1. use a disc cutter to remove some of the slab and put some insulation in, maybe 50mm? but this will go through the top mesh sheet resulting in there not being any cover for the mesh on the sides for the top sheet. 2. remove the 200mm thick concrete slab on the outside of the blue line entirely and put the full 200mm deep insulation in there but, again, I'm worried about the lack of cover for the rebar. 3. another solution could be to simply put some insulation on top of the slab but I'm not sure how that will fit in with the timber frame sat on top as it's obviously not been designed to have 100mm insulation there but as there's 75mm mortar and coursing block and then the soleplate it would probably be ok as 100mm insulation would then cover up to the top of the sole plate. e.g. so that could potentially work and will reduce the impact of getting rid of the cover on the mesh. We're planning a 75mm sand and cement screed internally so there's no height for insulation internally. Can anyone recommend a course of action listed above or something else I've not thought of please? the groundworker is coming back tomorrow and I'd like to have a plan of action for him.

today I learnt a very important lesson that I hope will assist others reading this in the future. this is important so please pay attention...... ....KEEP ON TOP OF YOUR WASTE MANAGEMENT!!! I decided that I thought it would be easier to get to the stage when we were out of the ground and then I would spend the time getting rid of the waste rather than getting a skip on-site early and clearing up as the build went along. that was a BIG mistake! just spent the whole day going through mounds of waste sorting it all out ready for skips to be delivered next week. ? moving forward I will ensure there is a skip on site at all times so the trades can put their waste straight in to it rather than just piling it up for me to sort out later.

my understanding was that the benefits of an air permeable roof membrane like the Tyvek Supro is that it allows you to remove the need for the air gap between the insulation and the roof battens as long as you have counter battens in place. that way you can fully fill your rafters with insulation.

shame no one told me that. I'm sure I'll figure something out!

I agree with @Declan52, it really just sounds like a sales pitch. but I am a cynical b*****d.

I hadn't even got that far in my thinking yet! the basement will be the last thing that gets done as the above ground takes priority but I will need to build a false ceiling to conceal the MVHR, plumbing, electrics etc. maybe I should start thinking about it as if I need clips like that there's no way I can install them after I screed on top of the block and beam. thanks for the prompt.

here's our block and beam finished. but I've been in the basement taking down some of the scaffolding deck that was for fall arrest and noticed that there are a few block that are cracked down the middle! so they'll have to come out and be replaced as well. nothing is ever simple.

I feel your pain. our brickie couldn't work yesterday as his car had broken down and today he turned up but the groundworker didn't have anyone to labour for him and with his dodgy knee he couldn't do it on his own so he left saying he'll be back tomorrow. I've got the scaffolders coming Monday to start that and the timber frame the following week so I really need to get this done! good luck and I know how hard it is to swallow those delays and the only consolation I can give is that those 2-3 weeks will whizz by and before you know it it'll all be done and the delay forgotten about.

hi all, just to resurrect this thread briefly as our coursing blockwork is starting tomorrow. The groundworker is now proposing that we run the membrane as follows: so with the VCL membrane going outside the block and then in on the underside of the coursing brick and then up to join the timber frame walls internally (previously I had the membrane on the inside of the block running between the hollow core/block and beam and the block). anyone with a better knowledge of physics able to tell me if this new solution is an issue? I can't think of it being one but thought I'd check on here first

congratulations! we're just going through this at the moment and hoping that they'll be finished tomorrow. I completely understand how great it feels! ?

counter battens aren't required *if* you have a gap between the membrane and the insulation. it doesn't have to be 50mm with Roofshield though, just enough so that any water than runs down the membrane isn't in contact with the insulation (I think Proctor say 15mm but believe my BCO said 25mm iirc). I believe this is obviously only an issue if you're insulating between the rafters. if you're insulating at joist level then no counter-battening is required I guess https://www.proctorgroup.com/products/roofshield this page has detailing for different roof types for the product.

It's not a great deal of time if doing continuous strimming. The last time I did a lot of strimming I think the 4.0AH battery I have probably lasted 15 or 20 minutes or so (sorry I wasn't checking the watch so those figures could be out!). I then switched to the 2.5AH battery I have and that ran out when the 4.0AH battery was about 75% charged. so, in theory, if you had a couple of the 5.0AH batteries I see no reason why it wouldn't last long enough to fully charge the other one. this whole thing is caveated by the fact that I have the multi-tool and a dedicated strimmer/brush cutter might be more efficient. check out the Ego line of tools. I've been very impressed and also have their chainsaw which made pretty light work of the trees in our back garden that came down to make way for the build. https://egopowerplus.co.uk/about-ego I'm sure the Makita ones also do the job and if you're already part of the Makita power tool eco-system then you'll already have the batteries but as I'm an Erbauer user I had the freedom to choose a different manufacturer for my garden tools. hope that helps

ps. I now have an Ego battery power tool all-in-one jobby that I use for multiple tasks now. it's very good indeed but for a large job you will need multiple batteries so one can charge while you're using the other. (or just take a beer break while your battery charges)

I bought an Einhell strimmer. probably not the best but it did the job. I didn't want to spend a lot of money on something that wouldn't be used much once the growth was under control! if it's for a one off job to clear a large area could you potentially hire one for the job? not sure on hire prices though so it might be best to just purchase one.

don't know the answer but that sure looks like some nice neat plumbing on that manifold. ?

we also looked at these when looking at Internorm windows but in the end decided not to go that route for some of the reasons @ProDave has mentioned but also when doing the maths it was cheaper to get external blinds integrated into the building which we thought was a better solution.

I don’t have a site diary but I do have a time lapse footage of every day of the build so far with 1 frame every 30s. So unless someone runs on site and then leaves within 30s I think I’ll have footage of them.

Depending on the roofing membrane counter battens may allow you to fully fill the rafters with insulation. Single battens will mean you’ll need an air gap between insulation and membrane. check with building control first though as I believe some will want an air gap regardless.

Welcome. sounds like a great project. please share photos, drawings, designs etc. we love that sort of stuff. ? I'm going through this exact thing at the moment. quotes for AC are coming in at between £2k - £3.5k per room! so I've been reading a lot about Fan Coils on here and I know that @joth is going through some DIY experimentation with his at the moment and I am waiting with excited anticipation to hear about his results! I also echo the above comments about taking a step back for a short while to decide what it is exactly you want and to investigate/design the MVHR now and consider insulated slab over traditional foundations etc. yes it will add a delay to your build and as I'm about 5 months in to my build and aren't quite finished in the ground yet (we're building a basement) I know all about how frustrating delays can be but sometimes they're unavoidable and the best thing to do. my experience so far is that things come at you thick and fast and you can easily get caught up in it all and miss important details. good luck and we look forward to seeing the progress.

good luck! I look forward to following your journey if you're kind enough to share it with us here. ?

exactly how I plan to do mine!

is this really necessary? seems excessive when you can just get ufh pipe staples to hold the pipes down. maybe someone who knows what they're talking about will be along soon to correct me. ?‍♂️

it might be worth thinking about this all some more and how the SAP will fit in with the rest of the design/build of the house. for example, you might find a company to design all your M&E requirements who can also do thermal modelling or PHPP and then the SAP can be bundled in with all of that. I mention this as we just went with the architect's choice for SAP and thermal modelling and had a lot of hassle with them but we didn't know any better. A little further down the line after I started looking in to MVHR, ASHP, Solar PV design etc I came across a company called Enhabit who are doing all of those for me and they also do thermal modelling/PHPP which would've given us a much better picture of how the whole house will work together. so, maybe it's worth putting it all under one roof? I guess it all depends on what your goals for your house are.

I used https://www.landscience.co.uk and was very happy with the cost and report. based in West Sussex but they might be willing to travel to Hampshire.

I guess if you're building a simple rectangle then yes. but our architect designed something a little different and we have above ground structures that aren't above the basement so it's a little less than 1/3. more like 25% of the total area.