Numerous roofing systems for steep roof (moderate to highly sloped) applications are common to this area of the country. Learning as much as you can about their properties is important.
CONCRETE TILE – This is the most popular type of roof currently installed. Concrete tile often have a 50 year warranty on the tile itself, not the installation, and they come in many different colors and shapes. We often find flashing defects, attachment problems and broken/displaced/missing sections on the average tile roof. The felt underlayment is the primary waterproofing membrane and usually lasts between 20 and 40 years if it is the minimum of 30 pound felt. At that time the entire roof must be stripped and the underlayment must be replaced. If a 90 pound granulated underlayment is used, this roofing system can last a very long time.
CLAY TILE – Like concrete tile, a clay tile roof comes in many colors but is most often found in the barrel (mission style) profile. This roofing material is fragile and must not be walked. Material quality for clay tile varies and some Mexican varieties deteriorate very early. The minimum 30 pound felt underlayment is allowed but we strongly suggest a 90 pound underlayment be used. Broken tile are commonplace on this type of roof and the 90 pound surface below is a major benefit. Flashing details are again critical with this roof system.
COMPOSITION SHINGLES – Still a very popular roofing system that does work well in this climate. Warranties vary but are most commonly in the 20 year range with the lighter colors and architectural profile design lasting the best. Shingles are often subject to wind damage during our summer monsoon season. Some homeowners believe they can install this type of roof with a few friends and several cases of beer over the weekend. As a result, we see many unreliable shingled roof surfaces due to installation defects. Also when a second layer is installed it will last at least 25% less than the warranty period specifies and cost more when tear-off is eventually needed.
WOOD SHAKE – This roofing type is not very well suited for our dry climate but the distinctive look of this material still makes it a popular option for many homeowners. The installed cost of wood shake is high because it is very labor intensive to install. We see these roofs last from 15 years to around 25 years on average. It is best to keep up with maintenance on an aging wood shake roof in order to extend its useful life. As this material ages the individual shakes become thin, split and often become dislodged. Ridges should be replaced when necessary and individual shakes replaced, as needed, for maintenance. “Oiling” these roofs with compounds designed to prolong the life of the shakes seems to only work in our climate if installed regularly, like every 2 to 4 years.
BERMUDA TILE – This roofing system is usually existing on a resale custom home from the 1970’s or 1980’s and it is rarely applied today. The composition of this roof consists of a lightweight foam/concrete mixture with integral color that is spray applied over a felt underlayment and then stamped into the shape of relatively thick flat tiles. The underlayment on this roof is critical due to the fact that the surface cracks like any other concrete product. Ridges and perimeters fail first and the industry forgot to devise a practical repair method for this product. As a result we usually see standard caulking installed to seal the numerous cracks that have developed over the years. Any of these roofs in service today must be considered generally unreliable. Prepare for complete tear-off and replacement with a more practical roofing system.
FIBROUS (ASBESTOS) SHINGLE – Commonly installed in the 1950’s, these types of roofing systems are now at or very near the end of their service life. The individual sections are laid in a shingle like pattern. This tile is about a quarter of an inch thick and has a unique look. If you see this type of roof plan on getting estimates to remove, properly dispose of, and replace the surface. Every one I have seen in the last two years was in need of immediate replacement. The most common complaint in the home inspection industry nationwide is for a roofing defect. Good inspector’s note all defects they are able to detect and call for further review by a competent roofer. Any roof defects noted in the home inspection report must be followed by a complete evaluation by a licensed roofing contractor before closing escrow.
Advantage Inspection Service offers Arizona Home Inspections for homeowners in the Phoenix metro area.