SIP flat shed roof vent channel
Sorry another SIP roof question, I’ll try to be brief!
Having read a number of articles, namely (https://www.greenbuildingadvisor.com/article/is-this-sip-roof-in-trouble)
I am unclear if my low-slope application should have a vent channel above the SIP panels. My SIP supplier here says SIPS are always ‘cold’ roofs and to install a vented channel with furring strips and 3/4″ ply over the SIP panel but given my understand that flat roofs like this don’t vent properly (from Martin’s other flat roof articles), is this necessary? Or can I just adhere the EPDM to the SIP OSB?
– Location is SW Coast of the UK, I’d say 4C climate zone although probably warmer in winter in reality
– Proposed 8″ SIP roof panels with EPDM rubber roof on top
– Roof is 1/12 mono pitch shed, 23ft wide by 14.5ft (this is a small holiday home)
I know many on here are not fans of SIPS, but the particulars of this site location mean a 300 yard walk on a path hand carrying all materials. Me and a crew can install the SIPS in two days rather than lugging down framing material, insulation, ply etc and stick building (which if it wasn’t for the site location, would otherwise be my preferred approach).
Being based in Europe, the high spec air/vapour tapes are readily available and will be employed in the air sealing of all panels joints with gaskets at the plates, foam in the seams etc. Doing the work myself I can be vigilant about this, plus the building is very small.
Of course, if the consensus is that the SIP roof approach is risky, I could frame the roof ‘traditionally’, probably 2x8s, ply deck and 2″ of closed cell spray foam the underside balance filled with rockwall.
You advice greatly appreciated.
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