Redbeard

Is that not exactly what is shown in GBS's dwg, or have I misread it?

Hmm, perhaps depends on which way the joists run and when the floor goes in. Could you saw the facing bricks to half depth, sit CF across the cavity then fix thro to inner leaf as previously suggested? Trying to think in 3D and failing, so have I missed a bridge there? Don't *think* so...

Not sure I know what you need. I think it *is* supporting (or partly so) the door-set, but it gets its 'supportingness' from being bolted to the slab. I assume your circumstances are different. Can you confirm what you would need it to do as opposed to what it's doing here?

Soudal do an air-tight foam. The one you link to does not claim to be. Decorators caulk I suppose could be, but a lot depends on adhesion, substrate etc. I think this may be somewhere where you use Passive Purple as 'belt and braces, but see if others agree.

Yes, lots more info and pics, please. How deep a reveal are they on? Is the leak all round? Is it concentrated at the top/sides/... where? Have you established that the leak is at the window-frame - timber frame joint? Could it be the opening lights somehow not sealing? Lots more please!

Forgive the Q if the answer is too obvious, but you say ''the gap between the screed and the external walls has been filled with expanding foam''. Was this air-tight foam? AIUI All air-tight foam is claimed to be air-tight (of course!) but not *all* exp foam is air-tight. I would not bother is *air-tight paint* over *air-tight tape* unless you feel some of the adhesion is less than 100%

Use lime if you can. If you want to use a fair bit of time just chop out the 'baggy' bits, fill with NHL 3.5 (or lime putty) 1: 3 with grit sand, and then re-skim the whole with 2 or 3:1 sand and lime putty (or NHL 3.5). A little more tricky on the L & P ceilings, where chopping bits out may dislodge the lot - but it may not. If you want to experiment a bit, as it does not have to be too strong, you could buy hydrated lime (available at most builders' merchants as it is sold as more of an admixture to sand/cement than as a 'use it alone' thing), soak it in a metal bucket or bin and make your own lime putty. As long as water stays on top of it it will remain usable - for years.

Youtube has gun-fettling videos. I have probably 5-10 guns waiting, and I have done a couple in the past. From memory it is a PITA, but it works.

Good! Glad that's cleared up then!

When you say 'pitched warm roof' I think you are referring to PIR board fixed *inside*, under the rafters. Strictly a 'Warm Roof' is where the insulation is *on top of* the roof structure, just below the membrane and slates, thus all of the roof timbers are within the thermal envelope. Can you confirm that you mean the former (or that I am wrong in my supposition!)? Either way, pre-June 2022 (target 0.18W/m2K) you'd have just scraped through with 125mm, provided the 'timber fraction' (the part of the 'insulation layer' which is actually wood, not insulation) is not unusually big. As far access goes for the remedial work how deep are the rafters? Common practice since 2010 regs in retrofitting roof insulation to sloping ceilings has been to fill rafter depth minus 25mm, leaving a 25mm vent gap between the membrane and the insulation. BEIS Best Practice guidance now states 50mm as the ideal, so you might, if your rafters are less than 175 deep, find that you have to fit insulation under the rafters too (which is in any case good as a cloaking of the thermal bridge - if you don't do that then add up the width of your rafters to see how much 'full-depth wood' is in your insulation layer. Anyway, yes, ceilings down - no way you could do it properly without. If you try, and can slide the insulation in easily then it is too loose. Sounds like you have a really irritating issue, and I wish you luck with the remediation.

Sorry to hear that! For SAP you need a (Full) SAP assessor. I think you need to know what they mean by 'heating certificate', because I am not sure I do. Elec cert should be OK if your spark is a member of a self-cert scheme. Unvented Cylinder Benchmark Certificate - not sure who you get this from but I doubt it should be difficult. 'Any Other certificate...' - MVHR? Best of luck.

Depends how much your roof void needed the 8. Would be a shame to use 2 and then find that you have a condensation problem in the roof void.

Not the Q, but I am intrigued as to how you will make a permanent, waterproof seal between the vertical glass and the roof glass. Will the roof glass meet the vertical glass via silicone, or will the frame of the roof glass be cleverly rebated so that the glass on each plane rebates into the frame?

'Skeiling' = sloping part of ceiling. Otherwise known as combs or sloping soffits.

Will you be marketing the small ships? Can I put in an advance order?

Is the ceiling already in? Or (hopefully) is the plasterboard still to go on? Have you any pics to show the issue? Membrane, lots of tape and some Passive Purple or similar? Of course stud walls make it more difficult, but unless everything is boarded up, that should not make it impossible. You'll just have to cut and tape around each stud (/top plate if applicable).

Fermacell Fine Surface Treatment, I think it is called. I have only ever used Fermacell once, for a part of IWI to a kitchen where we needed to hang potentially heavy-when-full cupboards on the wall. Instead of 25mm battens over PIR, then plasterboard, we used 25mm ply, then Fermacell, giving us 37mm (? - can't remember F'cell thickness) of hefty stuff (on v long screws) to screw cupbds to. We just had it skimmed in board finish, the same as the surrounding plasterboard.

14 hours ago, Temp said: ...and Sparrowhawk replied: My thought too. If you can hear it as you move, how much flex are you feeling in the floor? As per the OP's description The construction of the flooring is (bottom up): Concrete Plastic Membrane Plywood Laminate (glued down) The 'squidge' appears to be occurring between the concrete and the plastic immediately on top of it. I don't think there is any suggestion that the concrete is moving.

Question from Left Field... Do you have proof that the floor is insulated, as of course it should be? It still does not make great sense since, if it wasn't, the condensation would be on the *top-side *, not the underside, of the plastic, but I am trying to play Devil's advocate so that you ensure that all the variables, however unlikely, have been considered.

How is the knee wall fitted? If it was already there, then after carefully establishing that it was non-load-bearing I would have taken it out, insulated the entire sloping ceiling and then fixed the 'knee wall' (cupboard-front) through it to the (carefully-marked!) rafters. If you did that the wall is entirely 'on the warm side' of the insulation, with insulation above and a habitable room below, and there can be no thermal bridge, as I understand your description.

Both of these firms are in the wrong part(s) of the country but they might be able to signpost you to an 'industry contact': Green Building Store, Golcar and Solarcrest, Macclesfield. I note that GBS's approved installer list includes 2 in 'the South': https://www.greenbuildingstore.co.uk/mvhr-installers/ You might also try RetrofitWorks in London who may be able to give you a contact.

No it wouldn't meet the U value target, but if headroom is at a premium you could argue the toss if yopu needed to, but if Bldg Regs do not apply as it's not 50% or more of the relevant thermal element, arguably just do your best (though personally I would be trying to meet the target). Common practice has been 25mm, and some problems have arisen due to inadequate ventilation. In my view the gov't Best Practice guidance (https://www.gov.uk/government/publications/room-in-roof-insulation-riri-best-practice). Is well-advised. If you decide to go for 25 only then, when you do have the roof replaced, ask for written confirmation from your roofer that the membrane to be used is certified for use with a 25mm ventilation gap (and then check that they actually used that one). It goes without saying that ventilation feeding that gap (the 'ins' and the 'outs' should be checked and confirmed to be sufficient.

Hi, and welcome. I read 'I have suffered from mould exposure and it led to bad health problems, its been hell to be honest. ' as being in a previous house. Am I right? I assumed that because you had suffered before you were anxious to avoid them in the 'new' house. Or am I wrong and we're dealing with an existing known mould problem *in this house*, in which case others' Qs about why the mould is happening are relevant. Can you clarify?

Back to your original post - you said: 'Could I fit 50mm PIR between the rafters and then use 25mm PIR below the rafters before boarding over with soundbloc plasterboard, **then when the breathable membrane is fitted in the future back-fill will another 50mm PIR? Will anything done now be required to meet building regulations**?' (** my emphasis **) If you go now with the 50 between and 25 below you may need BC approval if it is more than 50% of the relevant thermal element (the sloping ceiling) *in the room you are stood in* (Regulation 23 of Part L). As 75mm would not achieve 0.16W/m2K you would have to argue practicability with the BCO. You also cannot automatically assume that you can fully-fill the remaining 50mm rafter depth when you subsequently re-roof. The BEIS retrofit Best Practice guidance for insulation over rooms-in-the-roof says 50mm vent space req'd, common practice since 2010 Bldg Regs has been 25mm, and only a select few membranes claim to be suitable for full-fill unless you are counter-battening on top, effectively putting the ventilation gap *over* the membrane rather than under.

What does the manuf'r say about air gaps on either side (i.e. top and bottom) of the insulation? Can you comply in the space you have? Can you get it air-tight? If it is only stapled, and you cannot get in to get air-tightness tape on then there is a good chance that it will just be something shiny sitting in a breeze.