nealblath

Not sure then Redbeard tbh The Insulation is between the rafters but we’ve to install a VCL under the rafters and then be covered over with insulated plasterboard. Then a breatheable membrane on top of rafters, counterbattens and battens, then tiles. we’ve to join the VCL of the pitched roof to the VCL of the warm flat roof to for a sealed complete roof

thanks for all the replies yeah, I wondered about the continuous ventilation with the pitched roof and the flat roof both being warm roofs. The architect said not to worry too much about ventilation though the ridge with the pitched roof having a breathable membrane under the tiles. I'd want to fit a dry ridge system for the ventilation but if I take the EPDM over the ridge overlapping the breathable membrane on the pitched roof, will this cut off the ventilation from the eaves to the ridge?

thanks for the replies lads lease see below with what I was proposing to do I asked architect and he more or less said ask a roofing contractor to sort it out

Hello guys, hoping you can help. We have bought a bungalow to retire to and are converting the loft into a dormer bedroom/bathroom. We are doing most of the work ourselves as we have fully renovated 2 houses before. We had plans drawn up by an architect and he designed the dormer roof to be a warm roof and the remaining pitched roof to be a warm roof too. The architect has drawn the pitched roof and the flat roof to meet at the ridge as can be seen from the drawing attached. He has specified that the pitched roof has a breathable membrane and counter battens to allow ventilation from the eaves to the ridge. We were thinking of installing a dry ridge system to allow for this ventilation. However, how can we seal the dormer roof to the ridge using either a dry ridge system, or refitting the original concrete ridge tiles which has a ventilation duct on the middle ridge tile? We will be covering the dormer with EPDM and was thinking of creating a little upstand of about 50mm under the ridge and creating an overlap of the EPDM over the ridge and overlapping the membrane under the pitched roof tiles, but want to make sure we don't ruin the ventilation path on the pitched roof side. I’ve read that you cannot cement onto EPDM so was thinking of putting a layer of lead flashing between ridge tile and EPDM. We have also to link the VCL of the dormer roof to the VCL on the underside of the pitched roof joists to maintain the vapour seal of the two roofs. Any help would be appreciated, thanks Proposed ridge detail.pdf