Flat Roof "leak" Need a fix for a year

[queenloris]

We have a small kitchen extension addition (at least 30 years old) on our 1918 house. The roof is flat and there is a slight valley where water collects a bit. It is always the last section of the roof to dry after a rain. Last fall, the plaster ceiling underneath this area started to flake and bubble a bit. I added some roofing adhesive (black tar looking stuff that came in a can and was recommended by the man at the hardware store). That seemed to work for a few months. But now, after many heavy rains, the condition of the ceiling is getting much worse. There are no actual drips - just moisture in about a 2ft area that is causing the ceiling to bubble and flake off.

I am looking for a solution that will last about a year. We plan on having the entire roof of the main house redone next fall (which is when we will be able to afford it). This will include either rebuilding this flat portion of the roof (hopefully to add a slope and possibly shingles - there is room to build this up).

In our area, it is very difficult to get roofers to come out and even take a look at such a small job. They are either too busy or unwilling. Is this something we can take care of for now and have the professionals take their turn next year?

I'd appreciate any advice!

[Togomor]

(just another diy'er here) I feel your pain, I have a small roof deck that I can't get any local roofers to even come out and look at because it's such a small job. I've been studying a lot lately prepping to replace the roof myself.

First, was your original roof an asphalt/tar material before you applied the tar recommended by the homestore guy? I'll assume it was... (if not, you may have a complicated situation)

Your local Home Depot should have a selection of Henry roofing products. The right material will depend on your local weather conditions, so read the labels. 208R might be a good one to start with. However these sort of patching materials are best if you've isolated the problem area.

If you've looked and can't locate the crack/hole then it may be a VERY small hairline fracture. In that case you may be better off applying a thin coat of "lap cement" across the entire surface. This a much thinner material and though it's not really intended as a patching material, it will seep into hairline crack and pinholes better than the heavier patching materials. However if you do this, *don't* put on a heavy coat, it is thin enough that if you put it on thick it may run right off your roof and down your gutters over the next few days until it fully cures. (it would move soooo slow you won't notice til several days later)

In either case, make sure you coat all areas upstream of where you actually see the problem in the ceiling, especially anywhere its flashed up against a vertical wall of the house or any other protrusion or surface change.

If you can access the attic above the ceiling you might check if the recent rains have caused your insulation to sponge up the water creating your lasting dampness.

[mrchris]

I agree with Togomor, cover the entire flat roof area with a thin coat of roofing tar. Your local home center should carry 5-gallon buckets of the stuff, as well as disposable broom heads.