Home Inspections Tips - Roofs

Marquís Home Inspections Tip of the Week  

Roofs  

By Derrek Hicks  

The function of the roof of a house is to protect the interior of the structure from external elements. In some cases the roof provides support for mechanical equipment such as satellite dishes, solar heating systems, and the like. The material used to cover the roof has a major effect on the amount of maintenance required to keep the roof in good condition. Roofs made of slate, for example, can last as long as 100 years! Depending on the part of the country in which a house is located, some materials are more prevalent than others. In the north eastern United States, asphalt shingles are very common, while in the south westclay tiles are more prevalent. Another common material is built up roofing which is used primarily on flat roofs on row homes in large cities.   Roofs are classified according to their slope or pitch. The slope is based on the rise and run - much like the classification of stairs. A roof with a 4" rise and a12" run is said to have a slope of 4 in12. Roofs are classified as follows: • Flat - 0 in 12 to 2 in 12 • Low slope - 2 in 12 to 4 in 12 • Conventional slope - 4 in 12 and higher    

Roofing Issues  

Installation

The issues related to roofing will eventually manifest themselves in the form of leaks. While the average homeowner will not have the expertise to determine whether or not a roof has been installed properly, there are some steps that can be taken to get a general assessment of the roofing material installation On roofs with a low or conventional slope, the homeowner can visually inspect the roofing material installation either with the naked eye or with a pair of binoculars. Roof tiles that are raised or out of alignment can be easily identified in this manner. More importantly, if the attic is accessible, the homeowner can take a walk through to look for evidence of water leakage.  

Old Roofs Asphalt shingle roofs can last anywhere between 15 and 25 years depending on the wear and tear of the roof. Wear and tear includes things such as weather conditions, installation, foot traffic, etc. In the United States, the south west side of a roof receives the most heat. It is natural, therefore, for that section of the roof to show the first signs of wear from ultraviolet light.   Here are some tips to help slow the aging of a roof: • Minimize foot traffic on the roof Climbing on a roof to perform maintenance tasks such as painting, gutter cleaning, satellite dish repair, etc. over time takes its toll on the roof. In the United States, the south western side of a roof receives the most heat. It is natural, therefore, for that section of the roof to show the first signs of wear from ultraviolet light. What typically happens is that the same area of the roof is accessed each time to perform these and other maintenance tasks. E.g., one particular window may be used each time to access the roof because it provides the most convenient method of access. • Trim trees that are resting on the roof Trees with branches that either rest on the roof or are too close to roof present a major problem. A number of things can occur under these circumstances: o debris from the tree can drop onto the roof causing deterioration o on windy days, branches rub against the roofing material removing the protective coating o excess moisture remains on the roof from shade generated by the leaves o branches too close to the roof provide easy access for wild life which can take refuge, or create their own openings, in the roof. • Ventilation The attic beneath a low or conventional sloped roof needs good ventilation to keep excess moisture from seeping into the roof's wood members. Ventilation also keeps the roof cooler in the summer which helps lower utility bills. In the winter, good ventilation helps maintain a consistent temperature throughout the roof's entire surface. This helps reduce the amount of ice that builds up at lower portions of the roof. The phenomenon of ice build up at the bottom of theroof is known as ice damming. Guidelines on roof ventilation o On conventional slope roofs, the ratio of ventilation is 1sq. ft. of venting space for every 300 sq. ft. of roof area o On low sloped roofs, the ventilation should be 1 sq. ft. of venting space for every 150 sq. ft. of roof area Good attic ventilation keeps excess moisture from seeping into the roof's wood members, minimizing rot. In the winter, good ventilation helps reduce the amount of ice that builds up at lower portions of the roof.  

Ice Dams

As mentioned above, ice dams are the build up of ice from rain water that freezes as temperatures drop rapidly or from melting snow that freezes under the same conditions. Ice dams are dangerous because they form ice sickles that can drop and seriously injure someone. Ice damns are easily identified in the Winter, however in warm temperatures one has to look for evidence of standing water on the exterior of the roof or water damage to the roofing members and insulation in the attic. Tips for preventing ice dams o Electric wiring can be used to heat the roof to melt the ice build up from snow or freezing rain o Following the ventilation guide lines from above is a very good way of preventing ice from damming. Keeping the roof cold in the winter causes snow to melt at a slower rate so that when the outside temperature rises again, the temperature in the attic is consistent throughout the entire surface of the roof This allows the ice to melt in a uniform manner. o Adding material to protect the eaves of the roof. Water proofing susceptible areas of the roof better protects the exterior and underside of the roof.  

Derrek Hicks

Marquís Home Inspections
PO Box 2699
Germantown, Maryland 20874
240-401-1418 ph
301-528-8503 fax
derrekhicks@marquishomeinspections.com
http://www.marquishomeinspections.com/