Rooftop ventilation key to comfy home

By Ken Kellar
Staff writer

Most owners tend to think of their attic as bonus storage space, if they think of it at all, but any contractor will tell you the attic is a key component of your home that can leave you in perfect bliss, or cause you all sorts of troubles, depending on how well it has been constructed, and ventilation is key to that experience.

The attic is typically a byproduct of most home building methods. When a roof is built with a peak, the sloping sides of the roof and rafters or trusses create an angular space between them and the rooms below. While some attic spaces are finished and turned into useable space for living or sleeping, many attics are left unfinished, stuffed with insulation and used as a means for climate control for the home. This Old House notes that 60 percent of a homes wintertime heat loss can be attributed to improperly insulated attics. Heat loss in the winter can also cause the snow that collects on the roof to melt in spots, refreeze further down the roof slope, and cause ice dams which can then lead to myriad problems as that continuing ice melt forces its way back into the home in a way it was never intended. In the summer, however, improperly built and ventilated attic spaces can collect humidity, which can in turn lead to structural and mould issues.

Therefore, in order to help control these issues, builders have installed roof ventilation systems to help regulate the flow of air, dissipate the buildup of humidity, and help the strain on overburdened air condition units.

There are several different varieties of roof venting systems available for homeowners to consider, particularly when building new. Most attic spaces have both an intake and exhaust system in place in order to allow air from outside the home to pass through and help draw out the air trapped in the interior. One of the more common varieties of exhaust vents is the ridge vent, which sits at the peak of the roof with a covering cap and allows warm air to escape. Another common vent that homeowners might see or consider is the box vent, which looks exactly like it might sound: a small box shape attached to the roof, often several in a row, that serve to let how air out of the attic space. The whirlybird is another highly visible roof ventilation system. Known as roof turbines, they are the silver UFO shaped pieces of aluminum which spin through the forces of the wind outside, as well as air escaping the attic space. The idea behind the whirlybird is that the spinning both lets warm air escape through the opening, as well as the spinning action pulling additional air up and out than a stationary vent might, though that can depend on other factors.

Other options for roof ventilation may include hardwired powered attic vents, off-ridge vents and even solar powered attic vents.

For those purchasing an older home, your options may be limited based on the size and layout of your roof, and it is worth speaking with a professional to determine if what is in place already is adequate in function and capabilities depending on the volume of attic space. One small vent may not be enough to adequately ventilate a larger attic space, or one method may not work with the layout of the established roof. This is an area where a professional’s opinion is incredibly valuable, as they will help you maximize the efficiency of both your attic space and the ventilation system, but there are several methods by which you can help keep both in tip top shape.

Firstly, regular roof inspections are a must. The homeowner can check the roof for problem areas and either fix the problem themselves – or call a professional – before those small issues get big and expensive. Things to keep an eye out for include missing, damaged or curling shingles, clogs or leaks in eaves, or even mold or moss growing on the roof. Checking inside the attic is also important, as water issues can be more visible inside the building. Damp spots in the attic can be surefire signs of a leaky roof, and leaky roofs also leak air out.

It’s also worth checking the insulation in your attic, especially if it has been used as storage in the past. Items in the attic can compress insulation, which in turn leads to it being less efficient. Newer, additional insulation can help to in crease the attics efficiency and keep the hot and cold air where it belongs, depending on the season. A professional can also inspect your attic space and let you know what steps might be necessary.

Finally, an easy at home method of keeping your attic in order in to manually inspect your ventilation system, whatever it might be, to ensure it is free of blockages and able to efficiently move air around. Clear out any obstructions like leaves or potential rodent nests in stationary vents. If you have a whirlybird on your roof, check to ensure it’s in working order (although the screeches produced by one in a state of disrepair are ear-grindingly obvious.) In the event your turbine is screeching, grinding, not spinning or anything else seemingly out of the ordinary, it will be time to contact a professional to repair or replace it, but the benefits of having functional vents in place are well worth it.