The following article appeared in the October 1999 edition of Rental Property Management.

As fall rains approach, it's time to check that roof. Rental property owners or managers should conduct a roof inspection at least twice a year, ideally after each major seasonal change, and absolutely before the fall and winter rains begin. Most roofing companies will also make inspections. A semi-annual inspection enables you to identify any potential problems and conduct preventative maintenance where needed.

Certain types of maintenance, such as leaf removal, may need to be performed on a monthly basis, depending on the maturity and density of landscaping. Buildings in heavily wooded surroundings often require monthly maintenance. Many owners and managers may not be aware of other causes of minor roof damage that, if not addressed, can lead to major problems.

For instance, we have seen many cases where workers, such as telephone, cable or satellite TV, heating and air conditioning, and tenants, who have been on the roof, have caused inadvertent damage. Many times this minor damage is nearly invisible but can eventually lead to significant problems if left unchecked.

Preventative roof maintenance will help keep present and future roofing related costs managed by extending the life of the roof and preventing water related damage to the inside and outside of the building. Moisture damage can lead to expensive repairs due to dry rot and sheet rock damage, as well as potential liability to tenants for personal property damage.

Damp conditions caused by roof problems can lead to the growth of mold, including black mold, mildew, and microorganisms. These can aggravate or trigger mold allergies in susceptible tenants and may result in expensive litigation and related costs.

Many major roof problems we have seen could have been prevented or minimized by a visual inspection and an inexpensive roof repair. Flat and sloped roofs should be inspected with equal scrutiny.

On a flat roof, the drains, waterways, and anywhere water collects or is channeled should be inspected. Remove debris, leaves, and tenant or visitor trash, (it is not uncommon to find cans, beverage or baby bottles, diapers, syringes and anything that can be thrown UP on a roof), all of which can obstruct the flow of water off the roof Obstructed drains on a flat roof will cause water to accumulate or pond. Standing water can cause the roof to fail, and in extreme storm conditions, cave in.

It is also important to check all penetrations on the roof (pipes, vents, AC connections and duct work), scuppers (roof or side drains), and downspouts, on a flat roof. Problems will often occur around the penetrations five to seven years after a roof is installed. Look for visible cracks and damaged or broken collars (around the top of the cones that surround a penetration). A cracked or damaged collar can allow water to penetrate the roof. Also check for splits or cracks in the roofing material at all termination points on the roof, such as at gutters and walls.

Most people don't know that roofs experience daily sheer movement: stress caused by temperature changes and the building settling. All roofs have around 1.6 inches of sheer movement each day, and up to three inches in hot weather. This can cause buckling of the roof. Look for stress cracks and splits in the roof surface caused by sheer movement.

Repairing splits and cracks are crucial to the life expectancy of the roof Mastic or plastic cement can be used to temporarily repair this type of damage. Long term repairs must be made in the original material of the roof. Repairs made using incompatible materials can actually deteriorate the original roof cover and aggravate damage.

On sloped roofs, water is shed via valleys, gutters and the downspouts. Accumulation of dirt, leaves and other debris can create a dam, which makes water build up instead off low. Problems will primarily occur where debris on the roof has caused a damming effect at locations where the roof terminates at a gutter, wall, fireplace or skylight. It doesn't take much debris to cause problems. A sloped roof (fiberglass composition, wood, etc) should also be checked for blown-off, damaged or missing shingles. These conditions can lead to leaks, but are easily repaired, which will eliminate the risk of water intrusion.

A major cause of roof failure on sloped roofs is insufficient, obstructed, or improper ventilation. Many existing shake and wood shingle roofing is being replaced with fiberglass composition. These roofs require greater ventilation per cubic foot of attic space than wood. Inadequate ventilation can severely reduce the life expectancy of your roof and may also void the manufacturer's warranty.

Visual inspections and maintenance can be done by on-site personnel. All roof work or repairs should be done by a state licensed roofing professional to assure the work is done with the proper materials, and in accordance with roofing standards and applicable codes. Make inexpensive, simple preventative roof maintenance a priority, and you can avoid expensive damage, liability, and greatly extend the life of your roof.

Dave Smith is President of Eagle Ridge Construction and Roofing. Eagle Ridge is a full service roofing company specializing in multi-family and commercial roofing. For further information call (916) 570-1460.