Pitched Roofs Waterproofing With Asphalt Shingles

1. The asphalt shingles I bought are easily torn apart. Are they kind of defective?

This phenomenon is absolutely normal. The majority of asphalt (bitumen) shingles are reinforced with glassfiber of 125gr/m2. This is a dimensionally stable reinforcement but with relatively low tensile and tearing strength.

The thing is that asphalt shingles don’t really need a high tensile strength from the moment they are placed on the roof. They need the stability a good fiberglass mat reinforcement can offer. So relax, you are on the right side.

2. What is the functional life of asphalt shingles?

Now this is a tricky question! First I would say that it depends. It depends on:

- asphalt shingle quality

- asphalt shingle weight

- the local climate

- the quality of installation techniques

- the quality of substrate

- the ventilation provided.

My experience says that in most cases 15-20 years is a very realistic number to take into account when dealing with first class asphalt shingles.Though,a lot of suppliers overpromise and this makes customers feed unrealistic expectations!

3. After the installation of asphalt shingles I have big quantities of granules in my gutters and drains. Why is this?

Don’t worry! This is an extra gift from the factory! It’s included in price!

It’s perfectly logical to have some granule loss. Some granules are marginally adhered on asphalt mass and in some months they detach. During fabrication much more granules /m2 are used from what is really needed. So this is not a problem!

Have no fear! Just take care to get your gutters and drains cleaned systematically during the first months after application.

  http://maconwaterproofing.blogspot.com

4. I have heard that asphalt shingles can be torn away by wind. Is this possible?

This is a phenomenon possible but not probable. We have seen such mini catastrophes in Greece!

To minimize the possibilities of such an unpleasant event you can adopt the following instructions:

a) Use only premium quality asphalt shingles. We have in Greece some “exotic” products that are really unbelievable.

b) Be generous with the nails. Buy the best!

They should be:

* very well galvanized

* head diameter: note less than 9-10mm.

* respect the recommended length. This has to do both with the asphalt shingle and the substrate. Never use 16mm nails as is very popular in Greece!!!

c) Fix the nails in a right way: Very deep and you spoil the shingle. Not deep enough and the shingle is on the air. The nail should be nailed vertically, otherwise shingle is harmed.

d) In high-wind regions use more nails/shingle.

e) Never use staples. Better to leave staples totally out of your plans.

f) Use asphalt cement under the tabs, in eaves and rakes, round penetrations etc. Though ,use it in very thin layers otherwise its’ shrinkage might induce deformation strains on shingles.

Chris Strogilis