2. Roof maintenance
4. Cathedral ceiling vent systems
Ice dams can occur when snow melts near the ridgelines of warm roofs (roofs without proper ventilation).
As water runs down the roof to the overhang, it cools and freezes. If the snow continues this melt-and-freeze process,
an ice dam can form; it can seep under the shingles, through the decking and into the house. The best way to prevent this ice melting,
is to stop the warm air rising from the home into the attic by making sure there is the right amount of insulation in the attic and also
proper ventilation to cool your attic.
Additional protection for your roof, in the form of
ice and water membranes, can be applied. Such a membrane would be installed on top of the decking, under the roofing
material. Please note that this membrane cannot stop ice damming, but it can prevent water from leaking through the roof sheathing.
Roof maintenance is one of the most overlooked areas in the upkeeping of any building. Neglecting a roof can seriously shorten the lifespan of any roofing system. Your roof needs ongoing care to protect your investment.
The best roof maintenance that one can do is to perform a yearly roof inspection to identify and solve problems as they occur.
Roofs get more abuse from the elements than any other part of the building; maintenance is a key element to saving money on
your roof by providing a longer service life. These tips will provide some general guidelines to help keep your roof in good
condition for as long as possible.
- Clean all debris from the surface of the roof.
- When moss and algae start to collect on your roof, zinc control strips may be installed along hips and ridges.
- Roof cement may be applied under any loose shingle tabs.
- Replace any damaged or cracked shingles.
- Check flashings, make sure they are not deteriorating and have no holes in them.
- Keep all gutters free from leaves, granules and debris.
- Check downspouts to ensure that they drain properly by water testing them (or wait for a rainy day).
- Trim back any branches touching or overhanging your roof.
- Check valleys for broken shingles (holes) or in the case of metal roofing, check for rusty valleys. Rust should be removed with wire brush, then the area should be primed and painted.
- Check all caulking and sealants. Remove completely damaged or broken caulking or sealant and apply proper product.
- Check chimneys for deteriorating mortar, damaged flashing and back pans.
- Re-nail any drawn-out nails and apply shingle cement or tar on any exposed nail heads.
Roof attic ventilation
- Proper ventilation is essential to ensuring that your roof will have a long lifespan. Ventilation occurs naturally when vents are placed at the base of the roof (eaves or soffit) and near the top of the roof (ridge) so that warm air can leave through the top and cool air can be drawn in through the bottom.
- Approximately half of the vents should be placed near the ridge and the other half near the eaves or soffit to encourage maximum airflow. If adequate ventilation is not installed, serious problems such as attic condensation, wood rot, mold, mildew and rusting metal will occur. These problems can affect the integrity of the roof as well as the integrity of the entire house and can even cause health problems for family members in the home.
- Proper roof ventilation will increase the longevity of your roof.
- Ventilating an attic has two advantages. In the summer, heat is released from the attic, keeping the house cooler and reducing energy costs if air conditioning is used. The other advantage is that ventilating an attic prevents moisture build-up, preventing wear and damage to your roof and attic.
Cathedral ceiling vent systems
One of the main reasons for having ventilation in a roof system is to remove moisture so that excess condensation does not form on cold framing components. In a cathedral-type system, each rafter cavity (between rafters) must be vented to prevent moisture from migrating through the ceiling and coming in contact with the rafters and sheathing. Vapor retarders help control the amount of moisture passing through the insulation. The most effective vent systems use continuous ridge and soffit vents to ventilate each rafter cavity separately. Attic rafter vents (thru vents) should be installed at the eave of every rafter to make sure the ventilated space is not blocked by insulation. A minimum of one inch of ventilation space in cathedral ceilings is required between the insulation and the roof deck although research should be done because some local codes require even more air space.