Hi, after getting some confused responses regarding airtight electrical boxes
//www.diynot.com/forums/electrics/airtight-electrical-back-boxes.393070/page-2
I was wondering if anyone knows what the situation is in the UK with regards to achieving Part L maximum air leakage of 10 m3/hr/m2 for new construction. This is for some research I'm doing. In the US, standard practice for 20 odd years has been to line the interior framing with a polythene sheet, taped at all joins and using airtight electrical boxes and recessed lights that penetrate the plasterboard. This also prevents interstitial condensation behind plasterboard where warm moist air from inside condensates on the cold side of the insulation, causing water staining/mould. Seeing as airtight electrical boxes do not exist here, and the only airtight recessed lights available are designed for bathrooms, I'm wondering how most new homes achieve the requirements? On the planning portal guidance
http://www.planningportal.gov.uk/uploads/br/accredconbk.pdf
it suggests that the plasterboard itself can form the air barrier, and to put plenty of mastic?!?! or adhesive around any holes e.t.c. surely this is not an effective method, and even if rigid foil insulation (e.g. celotex) is used, and foil taped/expanding foamed in place (which I doubt happens), surely all penetrations (sockets, switches, pipes, ducts, gaps under skirting boards, around frames e.t.c.) will cause massive air leakage and condensation points everywhere. Is there different practice for timber framed vs block construction? Is the air tightness testing actually implemented and enforced by building control?
any experience would be interesting to know
thanks
//www.diynot.com/forums/electrics/airtight-electrical-back-boxes.393070/page-2
I was wondering if anyone knows what the situation is in the UK with regards to achieving Part L maximum air leakage of 10 m3/hr/m2 for new construction. This is for some research I'm doing. In the US, standard practice for 20 odd years has been to line the interior framing with a polythene sheet, taped at all joins and using airtight electrical boxes and recessed lights that penetrate the plasterboard. This also prevents interstitial condensation behind plasterboard where warm moist air from inside condensates on the cold side of the insulation, causing water staining/mould. Seeing as airtight electrical boxes do not exist here, and the only airtight recessed lights available are designed for bathrooms, I'm wondering how most new homes achieve the requirements? On the planning portal guidance
http://www.planningportal.gov.uk/uploads/br/accredconbk.pdf
it suggests that the plasterboard itself can form the air barrier, and to put plenty of mastic?!?! or adhesive around any holes e.t.c. surely this is not an effective method, and even if rigid foil insulation (e.g. celotex) is used, and foil taped/expanding foamed in place (which I doubt happens), surely all penetrations (sockets, switches, pipes, ducts, gaps under skirting boards, around frames e.t.c.) will cause massive air leakage and condensation points everywhere. Is there different practice for timber framed vs block construction? Is the air tightness testing actually implemented and enforced by building control?
any experience would be interesting to know
thanks
