As Fall approaches, it is a good time to consider the importance of proper attic ventilation. Improperly ventilated attics are more vulnerable to Hoar Frost that can grow to become ‘sheets of ice’ during extended periods of extreme cold temperatures; then, during a Calgary Chinook it can literally rain inside of your attic which can destroy your insulation, and cause mold and mildew. An ideally-ventilated attic will have ‘soffit-to-ridge-airflow’. This is achieved by having ventilated soffits at the eaves and vented ridge at the peak of the roof, but do not vent the soffits at the gable-ends… because escaping air from the roof peak would be replaced from the closer soffit vents at the gable ends rather than pulling air into the attic from the eaves. Similarly, it is advisable to close off any ‘other’ venting such as gable-end vents, roof turtle vents, etc.
A properly ventilated attic will allow the home to be warmer during the winter because the ‘super cold’ midnight-to-6:00-AM air can be replaced with warmer morning air surrounding the eaves; also, the house will be cooler in the summer because the ‘super hot’ 1:00 PMto-4:00 PM afternoon heat can be replaced with cooler evening air allowing you to sleep more comfortably at night. Another reason to have ‘soffit-to-ridge’ venting is that during high humidity and sudden cooling temperatures, the snow/ ice accumulation on the roof at the eaves, creates a situation where the roof deck become ‘wet’ under the shingles, as well as the attic underside, because moisture is attracted from the air to anything that is colder than it is. Soffit-to-ridge air flow dries this area faster than static air will, plus when hoar frost accumulates, sublimation can occur (the frost will turn to vapour without becoming liquid first). It is extremely important to have soffit venting, working with ridge venting in ‘open beam’ ceilings in order to cause air flow between the trusses (your insulation will be much more effective, and retain it’s desirable qualities longer). Roof ‘turbines’ placed far apart, and near the roof peak, will also work with vented eaves soffits, because the turbine fins are constructed to keep rain & snow from entering the attic (do not cover them in the winter), and to draw the attic air out, creating the ‘updraft’ that is necessary for eaves-to-ridge attic air flow. Power vents, wind turbines, and ridge venting all work with vented soffits at the eaves to optimize attic conditions. Most roof ‘turtle vents’ do not give satisfactory results! Have a good Fall & Winter, and protect your home.
If you are uncertain whether your attic is vented adequately, consult ‘An Expert’.Read More
With a Calgary Winter just around the corner, it is still not too late to give your older roof a Fall ‘Tune-
Up’! Roofs past their prime often have loose flashings and vents which allows water and/or ice to creep beneath the protective roof covering. It is best to secure flashings & vents by removing any lifted nails and installing appropriate-sized screws. Skylights, chimney boxes, and fireplaces often have dried, cracked, loose, or missing caulking that can be removed (if still there) and replaced with fresh caulk. Loose, cracked, or missing shingles should be replaced; metal valleys should have the shingles lifted and resealed because caulk hardens with age and ‘breaks in the sealant’ can occur to allow water & ice to enter past the sealant barrier, and then not be able to find an exit.
Once this happens, a dirt trail is established which helps future water to more easily discover the entry into the valley and then onto the roof deck. Older shake roofs are particularly vulnerable to ‘age leaks’ because the oils in the felt that is installed with every course of shakes is ‘boiled’ or washed out over time, and the felt turns back into ‘water-absorbent-paper’. The felt disintegrates, and/or rots. As your shake roof breaks down and turns into much more ‘smaller sized shakes’, the ‘cracks-on-cracks on- cracks’ that now appear will allow water to pass through to the roof deck, and then into the attic.
Standard shakes are 24”, and are installed with 10” exposure, which means that there are nails through each shake at approximately 11” and 22”. Traditional shake roof repairs are affected by ‘removing old shakes and installing new shakes …however, while the nails at 11” high can be removed, but the ones 22” high cannot; therefore, roofers rip out the old shakes, and ram in the new shakes – destroying the felts protecting your roof and creating new cracks-on-cracks on- cracks in the process, which will eventually turn into leaks. A much better way to repair an old shake roof is to install 12” ‘shims’ in-between such crack-on-cracks, thereby retaining the integrity of the felt protection.
If you are cognizant of an ageing roof problem, but you’re not quite ready to replace it, an inexpensive ‘Tune-Up’ with a 5-year NO LEAK warranty might be a logical alternative, thereby extending the life of your roof. Have a good Winter and call ‘An Expert’.Read More