Roger440

Ive used it, and your description of "shoggled" is about right. Its nothing like whacking down type 1. Significant voids or gaps remain afterwards. A geotextile membrane was then laid before concrete/lime crete. If you didnt, the voids are such that the concrete would fall down into the voids, negating its insulating properties. The main reason i used it aside from being "breathable" (old house) if i can use that term is that it reduced excavation as it is both the sub base and insulating layer combined. Im not one for taking pics, heres a shot with geocell, membrane and heating pipes down

I think looking for logic isnt likely to get you far. Its government. Worse still, its the scottish government. One does have to conclude that the wood burining stove lobby are highly effective.

Foamed glass is easy to move as it weighs next to nothing.

Its 15 mins work to fit an isolater. Though you do still need to remember to isolate the incoming before you turn it on.

Exactly what i am doing. Boiler is oil, but clearly, still needs power to run. So a small diesel genset does that. If i ever get my forklift to be my battery bank, thats more than enough to keep the boiler running. My primary reason for sorting all this stuff out isnt power cuts, though we do a get a fair few usually no more than a few hours, its protecting myself and not being a victim of Ed's bonkers ideas and the inevitable power rationing that follows.

Good summary of the madness of road laying.

Government signals and actions suggest it is. I think you will find the public at large think it is too. Everyone who comes to our house, which now has the original fireplace opened up, ask if we are fitting a wood burner. Without exception, when i say no, they think we are mad, if i try to explain why, they think im madder still and some sort of conspiracy theorist. There is literally no understanding or concept of the consequences of burning wood inside your house.

Ive got this now. Surprisingly effective. But only in the living room, not the kitchen. Can have carpet in the kitchen! Nothing matches UFH for comfort. The costs are negligible, some UFH pipe and £200 or so in hire for the machine. Not doing it doesnt stop the heat loss through the uninsulated slab, though, accepted it will be less of a loss than with UFH.

I did the whole excavation thing at my last place, though primarily for other reasons, but insulated and fitted UFH along the way. To do this to my current place, even with me doing a lot of the work i reckon it will be circa £5k by the time im done. Significantly more if i paid to have it done. Thats an awful lot of heating oil.

Id suggest it will be fine. Yes, i didnt want the shallow step. On the face of it, its not much, but you do notice it in use. Bizarre really, your wouldnt think that would happen.

Very interesting. Thanks for posting.

Ill be doing it myself. You can hire the slot grinding machine, so straight forward enough, if tedious. Ive looked at an overlay, but given id be doing the whole ground floor, it causes to many issues with doors, thresholds and the stairs, so ive discounted it. My house is 1800's solid wall with no DPC, so im not overly concerned about "warming" the wall as it will help push the moisture outwards, but im gussing yours is rather more conventional? Im not convinced it will need to run at an overly high temp, but clearly it will be a slow to respond heating system. The one i did in my last house was semi insulated with foamed glass, but pipes right at the bottom of the slab. It worked really well and ran at 35 degrees.

Im in the same position. Without ANY insulation under. I intend to do likewise, just set it into the existing concrete. Of course, its a long way from ideal, it will cost more money to run than if it has proper insulation. Quite a bit more. Its all very well people saying dig up the floor, but that costs. A lot. I ran some crude numbers. Id need to live to well over 100 years old to see payback. Not happening. Got better things to spend my money on. The reality is, its makes no economic sense. Unless you are 12. Dont take my word for it though, crunch the numbers yourself. Use the Jeremy spreadsheet on here to help figure it out. Id imagine with 25mm insulation under, your payback will be even longer. Of course, it will be better done right. If i had unlimited funds id do it right.

You make a good point. Wasnt aware i can hang it out as long as it takes me. Which would indeed be quite a while! I do still have the issue of cost and risk of doing it with approval, which, seems, unless someone says different, inescapable.

Im intending to die here, but that may not pan out, so yes, when selling it can be an issue. Traditionally an indemnity policy is peanuts, because the risk of action was essentially zero. I bought this house in the full knowledge that nothing that had been done, boiler aside, had certification. My previous house proved that such certification, of which there was plenty, was to all practical intents, worthless. Had i relied on it as evidence of compliance i would have been most disappointed. But, yes, going forward, logically those indemnity policies will go up in cost as the risk of enforcement increases. But to get to the nub of it, if it was just the BC fee, that would be OK. But its not like i can present my sketches and say, i want to do this, is that OK? Unless ive very much misunderstood, im going to need "proper" drawings, SAP assesment, maybe a WUFI condensation risk analaysis for the walls. None of these will tell me anything i dont already know. However, i cant do any of these things myself. Things things are not £50. So i either spend significant sums on these things, with no guarantee of acceptance as i am departing from the regs, and the risk of further reports and / or changes to what i can do. Then ill have to do the same again later when i do the windows. And the back of the house, the cavity wall bit. Each time another 4 figure sum. It makes no sense to keep shelling out for things that add nothing to the house, for a project that even without those additional report costs etc is way beyond the 15 year payback period to which the regs refer. Essentially, my choices are do it by the rules with lots of extra cost incurred, with no certainty what the final cost will be, just do it with out approval, or do nothing and buy more oil (which is the financially sensible option). My takeaway so far is that i could probably get approval for my plans, but at considerable additional cost. Cost which adds nothing to the final result. Though im struggling to believe anyone will let me do UFH on an uninsulated slab?!? Im conflicted given the new penalties...........................................

Anybody have any thoughts on my random scribblings please?

Indeed, you have suggested this previously. I like the idea, though at a practical level there are some challenges, mainly the purlins that run along the roof blocking said airflow. And the roof is heavily shaded after midday/ early afternoon by 30m conifers. But ive not abandoned the idea. I did originally start a thread on how to heat the place at zero or close to zero cost.

Because im an idiot, i miscaluclated where the door would land, mainly because i changed my door solution post slab laying, but if we ignore that aspect, i put 2 inch EPS on the upstand where the door was, then cut it back at an angle so the block paving could run up to the concrete. So yes, something of a thermal bridge there. Could have put a thin sheet of something in the gap to actually break the bridge though.. Like a thinner GRP box section. Perfect, no, but light years ahead of any other garage i have had.

Yes, i mentioned that in my other thread about my house, which is why ive considered involving a BCO, where, normally i wouldnt. 2 years inside for fitting a window seems like overkill V the offence. How dare i. I should allow someone with a can of squirty foam, but sporting a fensa certificate to do a crap job instead. For my barn/shed call it what you will, trying to comply means costs approaching 100k. Its just a (big) workshop for my cars, toys and stuff. Not happening. I can of course make it much better for circa 20k, but that wouldnt be allowed. Even at £20k, its cheaper just to burn diesel. Id just prefer it stayed warmish at a more constant level, as it will be better for the stuff in there, and means it wont be freezing cold when i go in there in the morning. Takes a coule of hours for the blower to get it from zero to 12c.

With a sustained cold period very! Same as outside pretty much Walls are block cavity, so that slows things down, but is just cement board roof. Ive got waste oil burner with blower that i now run on red diesel, but that makes for expensive warnth!

In mine, with its completely uninsulated roof, its always noticeable warmer up near the roof. Pushing that air back down is almost free. Yes, OP seems to have disappeared? Shame as it looked interesting.

Yes, sadly the whole building regs issue comes up. Given the proposed insulation by the OP, im guessing thats the requirements for a commercial building as it clearly is less than domestic. I wont comply as to do so would be prohibitively expensive. The roof for mine, just the roof, came in at circa £50k. Id have to live until im 300 years old to see any payback. As always, the requirements put you in an "all or nothing" situation.

Circulation fans will be essential, and useful whatever else might be done.

I had EPS up the side of the slab. It was steel framed with insulated steel composite panels. So the panels were screwed to the frame. The inner steel layer is inside the the envelop. The insulated parts sits on top of the EPS, and so the outer steel layer is outside. Yes, the securing screws are a thermal bridge, but thats inconsequential id suggest. So no thermal break in the envelope

Hmmm, this is interesting. I too have a 3000sqft "warehouse" that is my workshop with some accomadation built in. The accomadation is insulated all round with 50mm PIR so not great, but OK. I want to keep the main area at 12c over winter. But without it costing a fortune. Ive spent ages going over all sorts of options, for insulation and heating, so far with no decision. The accomadation is currentl;y direct resistance heating which is bankruptcy inducing to use. All this talk of draughts is valid for your regular commercial building, but can be overcome with good attention to detail with the insulation. Its interesting that, almost universally in the UK, warehouses are unheated, with local radiant heat for operatives at packing stations etc. However, our owning company in Poland, their warehouses are all heated to 16c. Unsurprisingly, they are all heavily insulated. Pretty normal there. Ive also visted sevaral in germany, including a couple of huge ones. All heated. It can be done.