We plan to replace the top deck on a warm-roof project. It is a standard setup currently T&G lower deck -> VPL -> PIR -> 18mm ply -> shingles and the ply will be re-laid with OSB and EPDM used so the new roof will retain the PIR and be virtually the same except using EPDM as the weatherproof layer.
We are torn between self-install (with help) or using a roofer but one roofer is adament we need an air-gap between the PIR and top-deck OSB - his quote includes battening with thin (10-20mm) lathes between PIR and OSB.
I am fairly sure this isn't needed and I heard his other partner debating with him on it (but he's the gaffer and insists) but he's well-respected and very experienced. Realistically, would doing it his way cause any problem? Is there a benefit? If it makes no real odds I am not going to argue "because I watched a YouTube video" but if it's a bad thing to do, I would perhaps pick someone else if he's totally insistent doing this.
We are torn between self-install (with help) or using a roofer but one roofer is adament we need an air-gap between the PIR and top-deck OSB - his quote includes battening with thin (10-20mm) lathes between PIR and OSB.
I am fairly sure this isn't needed and I heard his other partner debating with him on it (but he's the gaffer and insists) but he's well-respected and very experienced. Realistically, would doing it his way cause any problem? Is there a benefit? If it makes no real odds I am not going to argue "because I watched a YouTube video" but if it's a bad thing to do, I would perhaps pick someone else if he's totally insistent doing this.
