saveasteading

Understood. And you've got the gas pipe there. If that was me I'd just ensure that you can change over in the future without too much disruption.

Yes, I think the current rule of thumb is to keep gas or oil if already in place but use ashp if all new. That may change according to what happens re the Iran situation. But putting in a gas pipe just in case makes some sense. Have you laid the yellow warning tape above it in the trench? If in doubt, bring it through a 110mm pipe bend and close both off with plastic and sticky tape.

Sorry about the nonsense speak in my first para above. I don't even know how to get that px character. I'm guessing this all happened in my back pocket. Ie I didn't edit and post consciously. What does it even mean? Ignore first paragraph.

It's very tempting to avoid any friction, but you di have to deal with it. The formal letter could be simpler I think.. if they are hard of reading it might just be binned. I believe your proposed works come under the PWA and you could cease all works and commence the PWA process up to you, but certainly get formal now. The friendliness, if you must, can be that you say your insurer requires that you send them this letter. They are liable for all PWA costs and the surveyor is impartial. You pay nothing and do not have to concede land, access, anything. The letter needs to be addressed really to them and dated. And you need proof of delivery so probably recorded delivery. You'll never be friends with them, but they will know not to mess with you. The consequences of not doing this would be much worse. Ohhh. And take lots of photos ASAP of the existing situation. I'm talking of 30 not 3.. from all angles and with closeups.

The cost difference can be significant. Two layers with staggered joints is better than one for insulation and stability. As it is softer eps will compress over any lumps in the floor and reduce gaps and hollows. With diminishing returns as thickness increases the lower eps works quite well. I got the best prices from the local BM, and 100mm was the best value £/mm. Get prices for 100mm and 150mm for both materials, then cost out whether the saving is worthwhile. I'm an expert in cutting it now. Handsaw only useful for 50mm or less. Stanley knife is very quick for 25mm. For 100 and 150mm , jigsaw with blade cutting within 5mm of the thickness, and complete by saw or knife. (Going fast the jigsaw blade wanders off line and verticality: for a few seconds more, the cut is straight. Pir is useless to cut with a handsaw. Eps easier but lots of dust. The professional who did most of the floor used a reciprocating saw but it was rather approximate.

Unless it is likely to be very wet there, I'd consider painting in bitumen. Use Blackjack starting with a diluted (water) coat as it will penetrate cracks and crevices. Then a slightly diluted coat over joints and then everywhere, and then a full gunge one. An extra coat over mortar and at the base too. A tar brush is often best.

Old boy surveying enhineer here. Age can help. Grounds how he uses þx terms aurveycand engineer (overused and oftenvabused, I say protectively.) All the advice above is very good. You really do need expert advice, and what you have so far seems sensible. You may be able to dig new foundation inside the garage slab. Breaker and some very hard work with a spade but a good labourer can dig 1m3/ hour.... if you can find one that accepts hard work. Thar way the wet end if the beam will become redundant. Big IF. I'm assuming the beams are not supporting the structure above. The wetness is another matter and there are cellar solutions.

Thanks for this. I'm not convinced on this argument but as i don't know much about these screeds I need to do homework. It does not have fibre. I've gone off fibre anyway as it clumps and is very inconsistent. It is a gypsum product, pumped. 49% club... I don't understand. Brilliant info: I was going to look into this principle. Cracks will be about 0.1mm and will refill with dust. Even if they did somehow open or close again, it would need a minuscule movement in the adhesive... and the grout should give way first. Quite right. In such cases I would often explain the perceived risk with the client, and often they took the saving. It could still be awkward if there was a problem, whatever the contract says. But it's for ourselves using the pension I've saved by making such decisions for decades. i. e. Questioning almost everything, especially the standard ways of doing things that nobody can justify. These are usually "trade" things where they say its best but hsve nil justifiication. Most radical experijents have been on ourselves. Some haven't been ideal but no dramas and usually it's fine. Strangely I see that the ufh pipes are mostly visible by having 1mm or so ridge over them. I'm thinking this has been by displacement of the screed after partial setting, and being walked on. But cracking is only visible in one place I've noticed, though if it's like concrete, there will be millions of tiny cracks/crazing. They didn't put crack inducers at doors and there are no cracks there, which suggests shrinkage is miniscule. I will research further.

That's a " day joint". Not a bad idea though to put a factory edge to work to. As compared to a piece of 4x2.

That's another thing that some trades-people "just do". Screed and slabs indoors do not expand. They may benefit from contraction joints/crack inducers but that is for tidy cracks as opposed to random ones.

If you could expand the logic, or instinct, please? At nil screed of course it would be impossible to tile: at 100mm you appear to agree with my logic. I have some hunch that there is a purpose for membrane at 40 /50mm but I can't grab the logic out of my head. Btw we will have 200m2 of tile (the rest timber laminate) so, at say £10/m2 plus any labour implications, it is a big cost. We're doing well on tile costs so to then add back 1/3 "for peace of mind" wrankles.

We have a lot of floor tiling to do. A recommended tiler says we "really should" have a decoupling membrane. I can't see any evidence that this isn't just an extra earner or " what most people recommend". The stated reasons online are. 1. Peace of mind. For the tiler or me? 2. Waterproof layer. no need. 3. Allows for settlement of the building. It's all on an existing industrial slab, 30 years in use. 4. a) Allows for shrinkage of slab. Ditto b) Allows for expansion and shrinkage and drying of screed. 40mm screed is already cured and isn't going to expand or contract . 5. Allows for thermal movement due to underfloor heating. I don't see that as significant. Any cracks are microscopic. 6. Ideal for Large Format Tiles – Enhances stability and strength. What difference does size make apart from the cost of big tiles? 7. Esp important with ufh due to heating and cooling cycles. I don't see 30 degrees as extreme 8. Enhances strength. I'd think the opposite is the case. To snap a tile it is bridged over soft material and point loaded. A tile cutter doesn't work with the tile flat on a solid base. So if i drop a pot I want the tile to stay solid, not deflect. My other cons. A. £7/M2 or more, plus waste, plus labour. B. We end up with a 10 To 20mm skin of ceramic, barely stuck down or restrained. C. The decoupler works both ways, and could encourage vertical movement under loads, eg table legs, and the grand piano. D. Even if the slab was poor quality, what is that membrane actually doing? Allowing the slab to move but leaving the tiles exactly where they are? I can't see it. E. The membrane acts as insulation on the wrong side. I've looked hard for any evidence and all I can find is that it is normal. Perhaps in a new build of questionable quality it is wise, and for small areas the cost seems relatively minor. I've currently got an old house with poor quality concrete floors. Large expanses of tile have lasted 15 years so far. Lucky again? And a holiday home abroad with lots of tiles on concrete. The only cracks are where I've dropped a log. I should explain. The project in question has 175 reinforced slab on dpm on stone, 30 years industrial use. Then 300mm eps and pir, and dpm. Then 40 to 50 poured screed with ufh. But I wouldn't be asking if I would not welcome opposing views or evidence. Any comments?

Worth insulating then to some extent. Bubblewrap to the structure and pipe insulation.

TLC for me too, unless I need hands-or -eyes-on. The prices are best of near to best. And heavy cable is by the m and saves waste. I think that SF and TS charge as much as they can, relying on just in time purchases on the way to the job. If it's not in stock that is a big failure in my opinion. And the likes of City Electrical charge as much as they can, relying on their trade clients using the credit account for cashflow. My most recent order from TLC was downlighters based on BH advice. Ordered one evening, arrived next morning in their own marked van. That service deserves repeat orders.

I think we are into the times of black plastic. Whatever the material, there will be a standard connector for you to take a loop off. You are going to have to gently dig an exploratory hole at some stage. I suggest now, and the ground may still be soft.