Self adhesive EPDM can (according to Permaroofs blurb) be used over (new) OSB with no problems. My concern with OSB is that it isn't "smooth". Once primed & the EPDM laid, it will only adhere to the highest point of the leaves of the OSB, leaving small pockets of trapped air elsewhere. This concerns me, would I be better off overlaying the OSB with 6mm ply to give a smoother surface for adhesion? My concern is about any trapped air expanding on a warm day creating blisters.
Or am I worrying about nothing?
Thanks
Or am I worrying about nothing?
Thanks