Thursday, March 22, 2012
San Diego Roof Replacement: How Do I Know if I Need a New Roof?
If your roof is damaged, you may be able to repair your roof rather than replace it. This is especially true with tile and shingle roofs when the problem is limited to one area. However, some kinds of roofs (especially on older homes) will have to be replaced.
To determine whether or not you need to replace your roof, you will need your roof inspected by a qualified roofing contractor. But if you would like a little background first, the following will give you some idea of what might need to be done to fix your roof and protect your home. If you have any questions about your roof, feel free to give me a call at (858) 537-6490.
Tiles are built to last a lifetime, but the underlayment is not. Because it is the underlayment that waterproofs your roof, it will need to be replaced every 20-25 years. This is called re-felting. Roofers remove the tile from your roof, replace the felt, and retile the roof. In most cases, unless the customer requests otherwise, the existing tile can be reused—saving you the expense of purchasing new tiles.
Ideally, roofing contractors should use 2 layers of 40 lb. paper. In San Diego we have found that many of the roofs that were built over 15 years ago don’t live up to our current standards and were installed very poorly.
Another type of roof we commonly see in San Diego, and the most predominant, is asphalt shingle roofing (more commonly known as composition roofing). This type of roofing system is far more durable than a flat roof or tile roof system. The most common asphalt shingle that we use here in San Diego is a dimensional 30-year or a dimensional lifetime shingle. Fixing loose or broken shingles is relatively easy, but if your roof is over 20 years old and most of the shingles are worn, you will want to look at replacing it.
Although they are rapidly disappearing in San Diego, occasionally we see old wood shingle roof systems. These wood shingle roof systems were used over 25 years ago and have not performed very well. They are also highly flammable. New local fire codes have made it so that there aren’t very many left. Given the susceptibility of our area to wildfires, you definitely want your home protected by a Class A fire-rated roof.
Flat roofs are not usually repairable. On older San Diego homes, it is common to see flat roof hot mop rock systems where gravel has been applied over tar. Unfortunately, we have found that things like wind, rain, and vibrations move the gravel over time. This exposes the roof to the elements and decreases its life expectancy.
We recommend torch-down roofing for flat roofs. With this roofing system there are embedded granules on the cap sheet that protect the roof and increase the life expectancy. Also, it makes it easier to track and fix leaks. When installed properly, the life expectancy of a torch-down roof is 15 years.