We had to tear off the slide roof (13' x 4' slide) due to water damage from the previous owner. We used the finished plywood for the top roof piece over the frame. We had intended to stretch some PVC rubber roofing material over the top as we had done with another RV slide roof, but opted to pay a guy to spread what he said was a liquid rubber roof instead. It is 110 degrees here and this sounded like money well spent at the time.
But, the product he used it appears was not the right thing for the job and we don't feel comfortable leaving the slide open in the rain, possibly destroying all of our work we did inside again. He didn't use a primer, but just spread a white paint looking product directly onto the finished plywood. We had him come back out when we saw it dried leaving MANY spots of plywood exposed (maybe it didn't adhere??). The product is one made by Henry, but it is the "Enviro-white" 100% Acrylic Elastomeric roof coating. It is basically fancy named paint from what we can tell. There is no body to it or build up of thickness at all. So, the roof isn't smooth and it impacts the quality of the waterproof properties of the seal when in contact with the rubber flap as the RV extends.
There is also a seam down the middle of the slide where the two pieces of plywood came together and this guy "filled" those in, but the product he used just shrank down when it dried. This created a sort of channel for water to flow back into the RV in heavy rain because the rubber flap obviously doesn't contour down into that channel.
So my question is... Would it work if we ran some butyl tape into and across that gap down the middle and then applied your Liquid Rubber over that and the entire roof? Would your product level itself out so we would end up with a smooth rubber roof on top of the tape and the acrylic-painted smooth plywood?