Roof Membrane Replacement-Need Info
Hi Everyone
In the first picture, I glued down some test pieces with the Dicor 901B/A EPDM adhesive…I wanted to see over a few days whether there would be a reaction with the old adhesive. I spoke directly with Dicor & they advised me that the 901 adhesive needs new plywood substrate in order to absorb the water based solvents in the glue, previous adhesive would prevent this process. The old adhesive stays tacky, so sanding is out of the question, adding a second layer of plywood is what I will do.
The 2nd & 3rd pics show the style of transition molding that our rig uses between the fiberglass caps & the roof/sidewalls. I am considering on going to one of the other styles, as they will permit me to adequately seal the screw heads, once the molding is installed. There is no physical way of sealing the screw heads on our style of molding. I have observed multiple areas of the rig fasteners where water has gotten under the screw heads, been trapped there & eaten the screw threads away, weakening the bond. The 2nd pic shows the membrane “under” the front cap, I am anticipating some difficulty in rotating the cap forward at the top, to allow removal of the membrane, & providing the additional clearance for another layer of plywood…I may have to create a knife edge on the ply. The rear cap to my surprise has the membrane also under, this conflicts with all my research, & basic physics, during rainy weather & travelling down the road, the preference would be to have the membrane on top of the rear cap, to prevent water from being driven under the cap in case of a crack forming in the “self levelling sealant”. I intend to try to do the “on top” method at the rear !
The 4th pic also shows that the factory used duct tape at the seams to prevent chafing, this was relatively successful, but I will be using a “glue impregnated” felt tape instead.
|