Friday, September 10, 2010

Seal A Flat Roof

Flat roofs aren't really flat but have minimum slope to allow sufficient drainage. Ponding, or pooling of water, on flat roofs is a common source of leaks because the drainage slope has been disrupted due to poor maintenance, bad workmanship or it is in need of replacement. Most roofs are sloped and allow the water to drain off.


Flat or low slope roofs require detailed workmanship and careful construction. Some slow slope roofs can provide 20+ years of service but a minor error could cause significant consequences. If you have a leak it is best to tackle the repairs as soon as possible as the longer the leak persists, the more repairs there will be. Does this Spark an idea?

Instructions


1. Look on the roof for imperfections (cracks, bubbles, fissures, holes, shrunken caulking) and defects in the roof coating. Use binoculars to magnify imperfections. Inspect integrity of all seams to check if the tar is adhered properly. Slide a flat blade, like a pocket knife, under the overlap. If it slides more than 1 inch (2.5cm) then this seam should be resealed.


2. Mark the irregularities. Use a dab of spray paint or place an object that will not blow away near the repair.


3. Clean the area to be repaired. Remove all loose material and scrape embedded gravel/granules, to expose the membrane. Clean all dirt, dust and debris with the broom.


4. Plastic Roof Cement


Apply asphalt plastic cement over the area and approximately 6 inches beyond the repair area in a continuous application with a trowel using constant pressure. Squeeze the plastic roof cement into the crack with the trowel. Continue to work the material into the membrane. Avoid contact with skin, wear rubber gloves.


5. Embed a strip of roof patching fabric into the first layer of cement. Trowel over a second layer of cement to cover the fabric using constant pressure and working cement into the fabric. Feather the cement from the edges of the crack to the existing roof.


6. Sealant and Roof Tape


Clean the membrane with alcohol or household cleaning solution, such as window cleaner. Wipe the surface clean with 'splice cleaner' or naphtha (white gas). Avoid skin contact by wearing rubber gloves.


Apply roof tape to the repair using pressure over the entire area to develop maximum adhesion.


7. Cover up repairs with roof gravel.


8. Keep checking for subsequent leaks after repairs have been complete.







Tags: cement into, constant pressure, layer cement, rubber gloves, slope roofs