I have an asphalt shingled roof with a serious problem. Due to a cathedral ceiling with exposed decking inside, part of the roof has insulation on top of the roof deck. As nearly as I can tell, during the last roof repair, part of the insulation was replaced with styrofoam. That’s right, white, beady styrofoam. The shingles were installed directly over the foam.
Well, over the years the foam has compressed (nails are sticking up above the shingles by 1" everywhere) and the roof is leaking everywhere. I was hoping to effect a temporary repair using asphalt roll roofing and cold lap cement. I want to cover the entire leaking area (about 60 sq. ft.) with the roll roofing, overlapping the good roof on either side and above by at least one foot, and sealing the new material to the old roofing around the edges of the patch with the lap cement. I would also seal each strip of new roofing to the layer below with the lap cement.
Does this idea have a chance of working? I’m looking for a few months, while I research how this roof should be re-insulated, repaired, and then reroofed.