saveasteading

Yes, but does the floor screed move or crack under the foot of Xander Fagerson? And will the tv packaging be strong enough?

This is getting into science fiction. I need a lie down. What is the cube root of time anyway? Or is it a way of proving that that entropy isn't what it used to be?

They have the best of the quoted prices online at present, along with Insulation Wholesale. Some others say they will match any quote but I resent that attitude and will tell them that they must quote their best price first as I don't give second chances. If they are too scared to do that then I don't fancy their service or security will be great either. What is the point of matching another quote unless their is some other benefit? @Susie was this recent?

I meant after a winter of the ground source pipes removing the therms. They look like this but with arms and legs: That needs an Ancient Greek letter. You mean deeper to the perimeter? It makes sense to have deeper insulation round the perimeter, and shallower to the middle, but that isn't happening. It's just going to be a less efficient area of the building, balanced by the centre of the slab being over-insulated. Perhaps PIR to full depth around the perimeter and 2 layers eps centrally is the pragmatic (and finicky) decision. It is intuitive rather than proven, but I'm confident I could write a page of 'proof' for the building inspector if it was necessary... but it isn't and will just be our decision.

We were discussing what to do with rooms that should be cool. Larder/ cupboard etc. and does the Utility room need to be warm? The current decision is to put the ufh pipes in anyway but not connect them, so we have full flexibility if (when) there is a revamp. I think the same logic can be applied to the whole house if ufh is a likely addition in future. If diy'ing the cost isn't great at this stage but simply wont be done at a future stage.

where, where, where please?

that's great to get real figures. Thanks. We have the constraint and advantage of an existing 175mm slab, and the insulation will be 200mm thick. Because of its HP/A being 0.2, we start with a U value of 0.35 with no insulation, with 100mm pir this becomes 0.21. For 200mm I haven't looked. It is from a very old manual with 'never throw this out', scrawled on it, because the 'uninsulated' graph is not often published. Interestingly one of the graphs shows that 25mm or 40mm are almost equally effective when hp/a reaches 0.15. Also that 60mm and 200mm converge at about 0.07. With beam and block, which I like in certain situations, the hp/a does not apply. I've just been reading a rather superficial article in 'Build-It' magazine. It happens to have an advert for ground-source facing it. It does mention the very high area of ground required for a surface system (3 times the house size) and the high cost of boreholes. But it doesn't mention that some ground is worse than unsuitable and that the pumping takes a lot of power. It says it never needs defrosting but I know that to be untrue for all cases.... or maybe the issue has ben sorted. In reality, surface systems are not heated by the ground, but by last year's sunshine. Slinky coils seem to have disappeared as they aren't mentioned. I wonder how much the temperature at 1m depth drops by the end of winter.

So far, simply using online published rates with no allowance for quantity.. celotex or other names all seem to be the same price as listed below, since when I've found cheaper but must check the spec. eps varies by vendor and many don't do it. please excuse that the Tab key doesn't work PIR thickness £/m2 £/m3 25 4 161 50mm 6 121 75 8.4 112 100 10.4 104 Now found approx £88/m3 120 12.7 106 EPS 25 2.16 86 50/75/100 all 86 unfaced pir 90-100 £8.51 £85/m3 as you will see, this bears out what some of you clever people have said about 100mm being the most competitive.

Apologies for an oversimplified discourse. I meant 'we' as the simple requirements of the regs for a new build, but with BH level of care and supervision. So it will satisfactorily airtight but with the resulting dribbles of air through the fabric, and more at fans and any vents. Good pun on manor/manner. Draughts was a deliberate over-statement. I meant airflow that isn't designed. Every time the front door is opened there will be a few m3 of air in or out, however well mvhr is designed. I don't suppose we will ever know the reality unless we here of a newbuild without MVHR that is failing on air quality, or someone builds 2 otherwise identical houses for comparison... and that won't happen. Plus cynical me says that there is an industry that sells mvhr, but not one that suggests not adopting it. Included in the decision are the weaving of ducts through the structure, the ease of maintenance , and the unknowns. Me? It remains debateable and I have plumped for 'not'.

I'm aware of that but reminders are no bad thing. I wonder how well a soft packaging eps would fare beneath 100mm or more of PIR and a grand piano on top. perhaps with a big enough dish under each wheel it would be ok. This is whimsical: I am not saving amazon packaging to try it.

Something else I didn't know. Seems to be a saw tooth but with a wavy profile to avoid sticking, and produces less dust. Between a saw and a knife. £22 The Bahco insulation saw has been specially developed for cutting various types of insulation material

Sorry I don't understand the question.

Best wishes everyone and esp thanks to the moderators.

Excellent graph thanks. May I ask it's origin? That's for an infinite area or based on some HP/A assumption? Theres a bit of a kink at 100mm ish thickness which seems wierd and that really underlines how worthwhile 100mm is. Severely diminishing returns after, I'd say, 200mm PIR. And no significant benefit after 0.3? ie a complete waste of resources.

I have awarded hearts to people I agree with.... which is contrary to good logic of listening to all views. But my prejudice, or is it exierience and intuition, is that mvhr is grossly over-rated. We build to control air leakage, then pressure test at high pressure with all fans and vents sealed. Then we remove the seals and allow draughts to flow freely from each wc and kitchen. Unless they have automatic shutters but they seem rare. Stuffiness can only raise from habitation, but then the fans are used which draw air from everywhere, to be replaced by whatever leakage there may be. Nobody suffocates. I've only had old draughty houses but the steading (family owned) has no mvhr and has no issues of stuffiness or condensation. I promise to report if that changes. In business I did no homes, but offices, nursing homes and school classrooms* would have the same issues..in all cases we agreed with the client to "chance it" without mvhr.... no problems reported ever. That's x 20 applicable projects at a guess. So I think I'm right. Still listening of course, but we don't intend to fit £20k on mvhr at the current project. * This seems extreme, with 30+ kids in a room. High ceilings help of course but window vents and door openings appear to suffice. Perhaps the teachers open windows sometimes.