After experiencing leaks in 4 different rooms over the past 2 years I finally decided it's time for major roof work. First step: coat the flat parts! The Ace hardware guy convinced me to use GacoRoof silicone roof coating which, supposedly, lasts for 50 years, and also fills small cracks, unlike the standard coatings.

Anyway I hope this is true because I used it! I had about 1100 sqft to cover, and with their coverage estimate of 100 sqft per gallon, and the requirement of two coats, this meant 22 gallons. At $50/gallon, it was about $1100.

First I rented a power cleaner for 3 hours and sprayed off the roof. I found that you have to hold the nozzle about 6 inches or less from the surface, and approximately horizontal, for it to be effective. This isn't so easy because the pressure makes the hose twist.

After that it was just straightforward work, putting down 2 coats over two days. I found their coverage estimate pretty accurate (there were 3 gallons left over) and I had one accident on the ladder which convinced me to let some else do my roofing work in the future!

full-size