On a tile roof when you look between the decking amd see a shiny reflective surface, is that (or does that count as) SWR?
If it a Self-adhering polymer modified-bitumen roofing underlayment applied directly to the sheathing or foam adhesive SWR barrier (not foamed-on insulation) applied as a supplemental means to protect the dwelling from water intrusion in the event of roof covering loss.
That is the biggest change, I do not believe has been made to the wind mit class. After some discussion at a large insurance carrier, they decided it would be acceptable to have an SWR under tile and classify it as a secondary.
I think most places at least Dade and Broward make them put down tar paper and tin tages then stick it to that and that is a waste if you ask me.
And will it appear to be an even surface in all cases? I looked between the decking on a tile roof and there was a sticky, glossy surface but it appeared to have brush marks. I know was regular peel & stick looks like but this had irregular patterns in it.
Rules may be different where you are I do not know.
Grace mfg rep told me that they would not warranty their membrane or the ice and water shield…even if the strips are under the first layer of tar paper due to the hot tar application.
I haven’t seen a roofer use a hot tar kettle in ages for a sloped roof. But, you are right, can’t use PnS under a hot mopped roof. Most newer tile roofs will have a self-adhered waterproof membrane (sometimes 2ply). In the HVHZ, they put the PnS over the mechanically fastened base. This would not qualify for SWR on the 1802.