Roof Damage Isn't Just What's on the Outside

I recently did work for a homeowner who was shocked to see black, rotten plywood underneath her roof. She never had a leak and wondered how there could be so much damage without any signs, other than an old roof that was deteriorating and needed to be replaced.

I see this problem a lot more often then you might think. In our area of Connecticut, 90 percent of attics don’t have enough insulation and aren’t properly ventilated. I meet people who need a new roof and want me to just replace the shingles to save money. What they don’t realize is how much deterioration exists where they can’t see. Once the plywood is exposed, warping, delamination, and rot from moisture usually come as quite a shock. 

So why does this happen? The issue is actually airflow. Attic ventilation allows your house to “breathe” by taking air in from the outside and letting air out from the inside. Too many homes that I work in aren’t properly ventilated and most have their bathroom and even dryer vents exhausting into the attic instead of outside. 

In order to have proper ventilation, your home needs a system that includes intake ventilation through the soffit or a new product called SmartVent which is installed on top of the roof near the gutter edge. Louver vents were typically used at an exhaust vent in the 1950s and 1960s but now ridge vents are more common. If your house has both louver vents and ridge vents, the louver vents should remain closed, otherwise, the louver will act as an intake vent and will only cool the top third of the attic. 

In the colder months, it’s not uncommon for me to see frost on attic plywood because of inferior insulation. Insulation and ventilation work hand in hand - the ventilation controls the airflow and the insulation controls the temperature. You’re probably familiar with insulation - it’s a cotton-looking fiberglass material that often comes in pink or yellow rolls. It can also be loose-filled into tough to reach areas with a blowing machine. Remodeling professionals put insulation between walls, in attics, and in basements to retain heat in the house in the winter and keep it cooler in the summer. However, without proper ventilation, insulation is just as susceptible to moisture and deterioration as plywood.

My customer never went up into her attic, so she didn’t notice the problem. What she thought was a simple roof replacement ended up being a bigger job simply because, after years of decay, the plywood she had was no longer strong enough to properly support the new roof. Ignoring the problem and laying new shingles over the existing plywood would have voided the new roof’s 30-year warranty.

The lesson for this week? If you’re going to reroof your home, make sure that the plywood is healthy and that your contractor has given you a thorough plan to ensure that your home is properly insulated and ventilated. It might cost a bit more today, but it will regulate the heat and cooling in your home, saving on energy costs and making you much more comfortable for years to come.

Bob O'Donnell is the owner of O'Donnell Bros, Inc., a Bristol-based home improvement company established in 1975. Email your questions for Bob to info@odonnellbros.com with the subject line “Ask the Pro”. All questions may be considered for publication. To contact Bob for your remodeling needs, call O'Donnell Bros, Inc. at (860) 589-5155 or visit www.odonnellbros.com. Advice is for guidance only.

Get Rid of That Funky Roof Mold

Have patterns of strange, streaky stains appeared on your roof this spring? My phone rings off the hook for roof cleanings this time of year, and as I drive around town, I see so many houses decorated with unsightly roof residue, which frequently emerges during the April rainy season. But what are the stains, why have they suddenly popped up, and what can you do to get rid of it? They are all good questions, so let’s get you some answers.

Stains on the roof are generally algae, which gets carried by wind or birds from roof to roof, and may not be visible until they have enough moisture, heat, and humidity to grow and spread. The manifestation of an algae problem is those black streaks that you see. Now don’t be too alarmed, algae isn’t necessarily going to ruin your roof immediately, but it does affect the curb appeal of your home and the problem could end up damaging and pulling up your shingles if not dealt with for a long period of time.

An interesting fact is that copper, zinc, and lead are toxic to algae, and many newer roof shingles contain copper granules, which act as a barrier against any mold growth. Homes with older roofs won’t benefit from this technology, but it explains why you won’t see algae where metal flashing has been installed. If you’re susceptible to algae and in the market for a new roof, be sure to inquire about this type of shingle.

So now that we know what it is, how do we get rid of it? The easiest way to rid your roof of algae is a good cleaning solution, which can be picked up at the hardware store, applied using a pump sprayer and rinsed with the garden hose. One tip is to give any plants below the roof a good drink of water beforehand so they don’t absorb the solution. If you’re not comfortable on a ladder, call a professional to help you complete this task. A clean roof isn’t worth a trip to the hospital, and a local area home improvement specialist will be able to complete the job in just a few hours.

Once the roof has been cleaned, you might want to do something to prevent the mold from coming back again. As I mentioned, copper, zinc and lead-coated sheet metal are toxic to algae, so installing a strip of flashing will help stop that nasty fungus in its tracks. Choose a strip that’s at least six inches wide, and have it installed at the roof peak to ensure that the metal molecules wash down with the rain and protect the roof from mold build up.

Bob O’Donnell is the owner of O’Donnell Bros. Inc., a Bristol-based home improvement company established in 1975. Email your questions for Bob to info@odonnellbros.com with the subject line “Ask the Pro.” All questions may be considered for publication. To contact Bob for your remodeling needs, call O’Donnell Bros. Inc. at (860) 589-5155 or visit http://www.odonnellbros.com. Advice is for guidance only.

There’s a roof fungus among us

Has a pattern of strange, streaky stains appeared on your roof this spring? As I drive around town, I see many houses decorated with a display of unsightly roof residue, which frequently pops up during this wetter time of the year. But what is it, why has it emerged and what can you do to get rid of it? They are all good questions, so let’s get you some answers.

Stains on the roof are generally algae or mold, which tend to crop up as humidity rises and warmer temperatures start to emerge. Now don’t be too alarmed, small black stains and mold aren’t necessarily going to ruin your roof, but they do affect the curb appeal of your home and the problem could end up being damaging if not dealt with for a long period of time.  

An interesting fact is that copper is toxic to algae, and many newer roof shingles contain copper granules, which act as a barrier against any mold growth. Homes with older roofs won’t benefit from this technology, but it explains why you won’t see algae where metal flashing has been installed. If you’re susceptible to algae and in the market for a new roof, be sure to inquire about this type of shingle.

So now that we know what it is, how do we get rid of it? The easiest way to rid your roof of mold is a good old-fashioned bleach and water mixture, which can be applied using a pump sprayer and rinsed with the garden hose. One tip is to give any plants below the roof a good drink of water beforehand so they don’t absorb the bleach mixture. Diluted bleach is a powerful compound that will clean the roof without any adverse effects, so long as you give it a good rinse afterward. There are other products on the market that will do the job, just pop into your local hardware store to find out what’s best for you based on your home’s symptoms.

Once the roof has been cleaned, you might want to do something to prevent the mold from coming back again. As I mentioned, copper, and zinc-coated sheet metal for that matter, are toxic to algae, so installing a strip of flashing will help stop that nasty fungus in its tracks. Choose a strip that’s at least six inches wide, and have it installed at the roof peak to ensure that the metal molecules wash down with the rain and protect the roof from mold build up.  

If you’re not comfortable on a ladder, call a professional to help you complete this task. A clean roof isn’t worth a trip to the hospital, and a local area home improvement specialist will be able to complete the job in less than a day.