GrantMcscott Posted January 31, 2023 Share Posted January 31, 2023 Hi Electritian has put all the cables in the loft and drilled through the pir insulation and burst the air barrier. Have pur my hand in the ceiling service cavity and air is extremely blowing through it. Tried sealing up all the holes and filling but still an issue. Very windy outside. I was thinking about putting 200mm of wool in the loft over the PIR will this stop the drafts coming from the loft? Link to comment Share on other sites More sharing options...
Jenki Posted January 31, 2023 Share Posted January 31, 2023 6 minutes ago, GrantMcscott said: I was thinking about putting 200mm of wool in the loft over the PIR will this stop the drafts coming from the loft? No. You need to fix the air barrier with tapes etc. Was the electrician informed of the importance of the membrane? If so ask him to rectify the situation. Link to comment Share on other sites More sharing options...
GrantMcscott Posted January 31, 2023 Author Share Posted January 31, 2023 Just now, Jenki said: No. You need to fix the air barrier with tapes etc. Was the electrician informed of the importance of the membrane? If so ask him to rectify the situation. I have tried taping and filling all the holes but it must be burst in other places that I can not find. Also the joiners nailed through it when creating the service void. So it will be an imposible task without ripping all the plasterboard off and taking out internal walls which is not going to happen. So I need to do the best I can with what I have. 1 Link to comment Share on other sites More sharing options...
Jenki Posted January 31, 2023 Share Posted January 31, 2023 Assuming this is cold loft, then if your looking for low ACH, then the issues need fixing properly. Is this a new build or refurb. Link to comment Share on other sites More sharing options...
Iceverge Posted January 31, 2023 Share Posted January 31, 2023 What is your build up as is? Can you access the top of the insulation? A sketch might help. Nail/screw holes are normally not an issue. We must have put 600 screws through battens through the membrane to create a service blood for the ceiling and still beat passive airtightness. I wouldn't let you electrician near the airtight layer, they'll only make it worse. You probably need to do this yourself. Link to comment Share on other sites More sharing options...
GrantMcscott Posted January 31, 2023 Author Share Posted January 31, 2023 3 minutes ago, Jenki said: Assuming this is cold loft, then if your looking for low ACH, then the issues need fixing properly. Is this a new build or refurb. It is a new build and we only have the issue on the north west side when it is extremely windy. I thought the wool and foaming where i see gaps would increase the ACH. As it is not possible to fix the barrier as it would cost to much Link to comment Share on other sites More sharing options...
GrantMcscott Posted January 31, 2023 Author Share Posted January 31, 2023 1 minute ago, Iceverge said: What is your build up as is? Can you access the top of the insulation? A sketch might help. Nail/screw holes are normally not an issue. We must have put 600 screws through battens through the membrane to create a service blood for the ceiling and still beat passive airtightness. I wouldn't let you electrician near the airtight layer, they'll only make it worse. You probably need to do this yourself. Will do a sketch tomorrow of make up but the majority of the insilulation I can access due to it being a story and three quarters Link to comment Share on other sites More sharing options...
GrantMcscott Posted February 1, 2023 Author Share Posted February 1, 2023 13 hours ago, Iceverge said: What is your build up as is? Can you access the top of the insulation? A sketch might help. Nail/screw holes are normally not an issue. We must have put 600 screws through battens through the membrane to create a service blood for the ceiling and still beat passive airtightness. I wouldn't let you electrician near the airtight layer, they'll only make it worse. You probably need to do this yourself. Hi Here is a drawing also to note that the ait barrier went in after the internel walls so it is not continuous and there is no air barier in the floor / joist zone. Link to comment Share on other sites More sharing options...
Jenki Posted February 1, 2023 Share Posted February 1, 2023 makes me sad, and angry, your options are very limited if you don't want to take boards down. I fear your results will be average at best. The actions you have taken to seal as best you can is all I can think of, just keep trying. Link to comment Share on other sites More sharing options...
GrantMcscott Posted February 1, 2023 Author Share Posted February 1, 2023 (edited) 7 minutes ago, Jenki said: makes me sad, and angry, your options are very limited if you don't want to take boards down. I fear your results will be average at best. The actions you have taken to seal as best you can is all I can think of, just keep trying. Yes there is so many mistakes on this build as I was not present alot of the time due to working away. My main concern is that I keep goining and i fail my air tighness test and have to rip the house apart to fix that. If that happened then I would need to give up Also Velux emailed me yestarday stating they have an issue with thier windows where they are not air tight and working on a solution to try and fix them Edited February 1, 2023 by GrantMcscott Link to comment Share on other sites More sharing options...
Jenki Posted February 1, 2023 Share Posted February 1, 2023 Just now, GrantMcscott said: Yes there is so many mistakes on this build as I was not present alot of the time due to working away. My main concern is that I keep goining and i fail my air tighness test and have to rip the house apart to fix that. If that happened then I would need to give up A lot of people on here have rigged up a fan and done a pressure test prior to plastering etc. you can go around with a smoke pencil and seal as much as you can before its all covered up, maybe an option for you to look at? Link to comment Share on other sites More sharing options...
Iceverge Posted February 1, 2023 Share Posted February 1, 2023 Unfortunately the electrician, at best, has been unbriefed and did not understand and hence scuppered your airtightness layer. I would let them know, kindly, just for education purposes but not expect anything more. I'm guessing the airtightness layer and service cavity continues down the walls in a similar fashion to the flat part of the roof? Not to worry all is not lost. I have 4 options. 1. Take down the plasterboard and repair the layer. Very small cost as the screws and boards will be reused and the tape required will be cheap. Done in conjunction with a DIY blower door fan it will be a cheap solution. 2. How big is the service cavity and is it empty currently? 50mm? You could possible get a spray foam company to fill it. @Gone West got a sub 0.6 ACH with just a thick layer of open cell foam between I joists. Advantage also of an improved U value. 3. Put another vapour control layer over the current layer of plasterboard and then a new layer of plasterboard. You would have the advantage of better sound proofing from the extra plasterboard. 4. Use the skim coat as an airtight layer. This will involve sealing all penetrations with appropriate tape, mastic and foam before the skim coat. You will need to foam behind the board around the holes. It may take a few try's to get every penetration sealed with the foam. I would lean towards option 4. Make a DIY blower fan for £30. Get plenty of IL330 foam and a good gun. I mean plenty. Like 24 cans/2 boxes. It isn't cheap but it's the best I've used. Different league to over the counter stuff. Best online price I found is here. Get every trade out of the house for a weekend when the first fixes are complete. Tidy it up so you can access every junction, wall to roof, wall to floor, wall to window etc. Then using the back of your hand to detect leaks go room by room and seal every hole and crack that you can. It is tedious and will require diligence. There's no point in just throwing a few quid at a labourer, they won't do it properly. It's not heavy work so anyone careful will be a real asset. If you have kids give them 50p for each hole they find! The better sealed you get, it the more small leaks will be detectable so you may need to do the house 3 times. A lit candle shoved in a length of conduit is the best I have found to find really small holes. Much better than smoke. We got 0.31 ACH50 with this approach although the airtight ceiling was intact. It might have taken 50+ man hours. Very satisfying work however. Impossible without a DIY blower door fan. 1 Link to comment Share on other sites More sharing options...
GrantMcscott Posted February 1, 2023 Author Share Posted February 1, 2023 I think I may of found the couplprit to the issue there is a soil vent pip going outside that is not sealed. Going to put a collar on it from the outside to see if that stops the draft coming into the service cavity. As it is in a fake wall then goes into the loft throght the service cavity. Will also go round everywhere and seal up have also been silconing the skirting boards at the bottom to make sure there is no draft coming throgh them Link to comment Share on other sites More sharing options...
GrantMcscott Posted February 8, 2023 Author Share Posted February 8, 2023 seems to be more than the lighting causing the issue. Would it be possible to spray in somthing to fill the cavity like cavity wall insulation and keep it away from the lights? Link to comment Share on other sites More sharing options...
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