Roof problem in Tucson, AZ

[hat]

Flat roofs that are typical of Southwest homes lead to an ever-present problem: Rain water pools in low spots and, with the extreme summer heat, cause the white coating to blister, eventually leading to roof damage and leaks. This is particularly true in the corners. I am thinking of building up the corners using plywood sheets supported on propely-slanted 2x2s and then using wood screws to secure the structure to the exisiting roof. This will be followed by sealing around the playwood and covering the entire area with cemented fiberglass tar paper in preparation for the white coating.

Am I going about it the right way? I have paid good money to so-called professionals with unsatisfactory results. Hence is my desire to undertake the project myself. Thanks!

[cm]

Your idea should work just fine but a few comments on the white roof coating.

The coating is not bubbling because of the heat. It is most likely from standing water working it's way through the roof coating and causing it to loose its adhesion to the roof. You can stop this by scraping the bubbled areas to remove the loose roof coating and then applying a generous coat of rubberized Koolseal roof primer and then top coating with your white roof coating. The white roof coatings will not hold up to standing water with out the primer. The best way to rid yourself of roof problems is to raise the areas where the water stands so it will run off as you are planning to do.

cm

[dpb]

How big a roof? The corners will be built up this way, granted, but the roof itself is still flat and undoubtedly will have low spots. On a flat roof here w/ similar problems when we had it re-roofed after the big hail, they used the 2" insulation board and built up several layers (3 I think I recall) at the one end and tapered them down to the original level at the other to make some grade. Been going on five years now and no leak/problem so far. Cut the amount of standing pools down quite significantly at very little expense over the simple replacement cost. SW KS, similar summer heat if not quite as long per year but colder winter and more moisture. Just a consideration if/when you do a whole roof again...