The following is a list of the common roof systems that are installed at homeowner association developments. Each system contains similar components: felt underlayment, plywood sheeting, sheet metal flashing, etc. Improper manufacture or installation of one or more of the roof system components could lead to a construction defect and damage.
Common Roof Types:
- Clay Tile (sometimes called Spanish or Italian tile): Made from red clay, concrete or both.
- Asphalt Composition Shingle: Made or formed from an asphaltic, aggregate and fiber mixture.
- Flat Concrete Tile: Formed concrete typically flat and uniform in shape.
- Built-Up (BUR): Two or more layers of roofing material covering the same roof area, cemented together on the job.
- Wood Shake: Usually made from wedged shaped pieces of cedar.
Common Problems:
- Improper and incomplete sheet metal flashing.
- Missing or short cut roof underlayment felts.
- Improper use of materials.
- Improper slope to drain.
- Lack of Gutters.
- Roof leaks.
- Gutters separating, improperly installed, or missing.
Possible Damage:
- Stains and or destruction of walls, ceilings, or floors.
- Wet Insulation.
- Mold.
- Fungus.
- Wood destroying organisms.
- Dryrot.
- Structural Failure.
- Defective or broken tiles/shingles.
There are four common problem areas in the construction of tile roofs.
- The ridge of the tile roof is left open to rain. The national Roofing Contractors Association (NCRA) and most manufacturers recommend that grout or other closure device be used to seal this exposed location.
- Open headwalls can be a source of leaks in a driving rain. Flashing and counterflashing as well as a grout closure are critical to provide a weather tight seal.
- Roof penetrations installed without flexible flashing. The principal concept is to make sure that any flashing is flexible enough to be “shingled” (lapped) into the tile assembly.
- Eaves should shed water, not collect water. Any water that gets under the tile surface should have a way to shed off the roof at the time eave rather than being dammed at the roof edge.
Consult manufacturer’s recommendations for the specific tile product.
There are common problems in the construction of flat roofs.
- Insufficient Roof Slope and Lack of Drainage
The Uniform Building Code (UBC), 1988 Edition, requires roof systems to be sloped a minimum of 1/4 inch in 12 inches for positive drainage.Most manufacturer warranties require roofs to be free of ponding water 48 hours after a rainfall (consult individual manufacturer’s specific requirements).
Where water cannot drain over the roof edge, the UBC requires a roof drain and an overflow drain at every low point of the roof.
Scuppers, or openings through the wall, can be used in lieu of overflow drains. the UBC requires that overflow scuppers be three times the size of the roof drain and have an inlet line located a maximum of 2 inches above the adjacent low roof point.
- Omission of Cant Strips
Some roofing materials are too brittle to make the 90 degree turn up the wall from the roof deck. Cant strips allow for the continuous transition of roofing materials without splitting or tearing that would permit water into the structure. - Lack of Proper Coping
A properly sloped sheet metal coping at the top of parapet walls will reduce the potential for water intrusion and eliminate most staining from top-of-wall-run-off.Stucco-capped parapet walls require a higher level of care in design and construction. Stucco does not prevent water intrusion, so the top of the wall should be waterproofed as if it were a roof.