Do you notice that your roof's asphalt shingles are curling? Is there a large amount of coloured surface granules in the gutters? If so, read on, because It may be a sign of something more fundamental than knowing when its time to replace " the ‘ol roof".

Many older, and some newer, homes were built with mistaken ideas about longevity or cost effectiveness. A further view into the attic may seal the reason. Many attic spaces are under ventilated. Under ventilated attic spaces tend to overheat during our long hot summers. This overheating causes a breakdown in the asphalt membrane structure of the shingle. Failure is in the form of cracking and breaking, rubbed off surface granules, and more notably, shingle edge curling. With these circumstances, close inspection will also show the shingles have become brittle, cracking and breaking easily under hand.

I remember an old concept of plugging the soffit vent spaces in the attic with insulation to keep the attic warm. The logic was that a warm attic meant less heat loss from the house. And yes it would, but for the results on the shingles. Alternately, a contractor may have only placed a thin level of insulation to save a few dollars. No one would consider looking in the attic space, eh? Both cases lead to our overheating and shingle failure problem.

In short, the flexible component of the shingle, a petroleum distillate has been evaporated away, leaving a hard crusty membrane behind to twist, curl, and crack. The end result is a shingle that no longer resists water penetration.

It may be too late to save the roof, but it is not too late to add more ventilation to ensure this doesn't happen again. The solution is generally simple, can be completed by a registered roofing contractor, and at a relatively low cost. Just make sure your roofer demonstrates their understanding of this practical approach and recommends a logical solution which would include adding sufficient roof ridge vents, and soffit baffles. Expect to have at least 1 square foot of vent opening to every 300 sf of roof area and baffles every second truss space.

As a side benefit, adequate ventilation will stop future  moisture related damages on the structural components in the attic space. Trapped moisture causes blackening of the exposed wood members of the roof structure. The blackening is a fungus that grows on the wood. Extensive moisture entrapment can cause the exposed wood members to rot. Electrically heated homes exacerbate this problem (something we will talk about in another column).

An alternate solution is to substitute asphalt with fibreglas. Fibreglas shingles do not exhibit the same adverse response to our summer heat load as does asphalt. It is a more expensive alternative, but it lasts longer and carries better manufacturer's lifetime guarantees. The fibreglas shingle also provides a broader and more stylized appearance, so it may be worth the premium on resale appeal alone.

At the same time, you may wish to top up the insulation levels in the attic space to lower your heating bills. This will also reduce the amount of heat loss from your home into the attic space. Twelve inches of fibreglas insulation is considered adequate these days. As a bonus, along with added ventilation, it will help extend the life of your existing roof. And bonuses are not to be sneezed at.

Craig Hostland is a Professional Engineer and Registered Home Inspector who owns and operates Pillar to PostÒ Professional Home Inspection for the Central and North Okanagan region. He can be reached at 765-4134.