Soft/Crunchy spot next to Roof AC

Consider making a 3/4" plywood collar that is the size of the gasket. Bevel the outside edge. You then can either slide under the roof rubber or place it above the rubber and secure it with Eternabond. The gasket sits on top of this and by elevating the gasket seal above the roof, the condensation drains away down the slope. I started out with a 6" width and then belt sanded the bevel so that the top surface matched the gasket outline.

If it's crunchy and you notice deformation under the rubber, you definitely need to get in there and fix it ASAP.

I would recommend opening the rubber roof as you suggest, but understand that the wood can really wick moisture FAR from where the leak is. Do your best to find the center of the damage and start cutting outward from there.

Hopefully it's just the roof sheet and your stringers are ok. If that is the case, you need to rip up the bad plywood to where it becomes solid and then make nice square edges to the opening. An oscillating cutter would make that task WAY more pleasant than any other tool. The replacement patch can just be nailed in.

If your stringers show some water damage but are "all there", I would recommend you treat them with Smith's CPES to seal and restore the strength of the wood. If the stringers are rotten, then obviously replace the bad sections. Again, that oscillating tool IS YOUR BEST FRIEND for that kind of work.

Once the wood is repaired, glue the rubber roof back down with 3M Fastbond 10 contact cement and seal the "+" sign shaped opening with Eternabond tape. That should make for a really good, water tight repair.

Jose

What a bummer. Sorry to hear of problem. No experience in this, but I would think cutting out the roof rubber back to solid area and gluing down a large patch piece with adequate overlap of new patch and original would be better, after replacing bad wood of course. Maybe 6 to 12 inch overlap???