Ice dams on roofs can cause drywall issues
Lack of insulation and improper ventilation cause ice dams.
JAMESTOWN — Homeowners who dealt with ice dams on their roofs may be having drywall issues and should have a qualified contractor inspect for any damage.
Ryan Krueger, co-owner of Building Professionals LLC, said the water leak problems might not be with the shingles on the roof. He said on the eaves of the house, the rain gutters will get full of water during the freeze-thaw cycle of the day, creating ice dams that cause water to get under the shingles and leak inside the house.
“Usually when we see all these problems, it’s almost always in March and April,” he said. “It’s when the sun starts to gain a lot of power because it will then start melting but then gets cold at night so then it refreezes and that’s what causes the ice damming.”
Krueger said shingles are typically darker in color and get warm when the sun is out, causing it to get warm inside the attic space and cold again.
“A lot of people especially in older homes don’t have the adequate amount of insulation or venting so therefore it will get warm in the attic and cold in the evening because the air is not circulating out of there enough because there is heat escaping from the house,” he said. “Then they will get frost on the plywood on the bottom side of the plywood of their roof sheeting and then when it warms up, the next day, it drips.”
He said he’s been inside houses where it looks like “it’s been raining” in the attic space when he checks the insulation.
“A lot of that is, I personally would say more lack of venting than lack of insulation but it’s both,” he said.
If a house is losing heat from inside the house to the attic, that will contribute to the snowmelt on the roof and cause condensation to form in the attic, said Dave Hillerud, vice president of Hillerud Construction Inc.
“Sometimes it’s not even a leak per say as it is condensation that just builds up,” he said. “Then you get the other side of the ceiling will be covered with frost, and the sun hits that roof on the outside on the right day when it’s warm enough and all that condensation that’s inside that frost that’s built up on the underside of the roof gets warm, melts, drips. So it might not be a hole where water is coming through. Moisture is coming in through condensation and melting of that condensation or frost.”
Krueger said the water leaking in from ice dams can take different routes into the house.
“Just because it’s leaking from a certain spot in your ceiling doesn’t mean that’s where it’s coming in,” he said. “It could be coming in 20 feet from there. It’s just finding a channel and coming in.”
He said the water leaking problems from ice dams isn’t happening just in older homes. He said the water leaks could be happening because of what direction the roof is facing but being in a shaded area can also contribute to the ice dams.
Moisture damage to drywall can be “very costly,” Krueger said. He said a lot of times the water will go down in a corner of a room and the drywall will need to be replaced on the ceiling and the walls. He said the damaged drywall will need to be taken out along with the insulation.
Indications of drywall damage include water dripping through, paint bubbling or turning yellow and cracked paint.
Krueger said some older homes might not have venting in the soffit. He said modern building codes require an equal amount of soffit venting as the roof venting.
“It never keeps it the same temperature as outside but what they are looking for is they are trying to get flow from outside, it’s supposed to flow up through the soffit and then the hot air go through your roof vents on the top of your roof,” Krueger said. “There is supposed to be constant recirculation through there and a lot of homes don’t have that.”
Hillerud said newer homes now have trusses with energy heels so the insulation is thicker at the eave.
“You can fill 12 inches of insulation right at the edge and still have room above that insulation for the air to get in from the soffit,” he said. “A lot of the older houses, that was all pinched down and people filled those with insulation, and now there is now fresh air coming in from the eave because the insulation is blocking it.”
If fresh air is coming in from the eave, other vents will need to be installed and made sure they are open.
“Even if you put in a power ventilator, like I say, it’s just like sucking air out of a balloon,” Hillerud said. “If there’s nothing else coming back in there, it doesn’t do any good. So, you may have to add vents to take in exhaust.”
Ice dam prevention
Krueger said homeowners need to have a qualified contractor check the venting of their house because of the many types of venting.
“They could have a ridge vent and not even know that they have a vent up there because it just raises your ridge cap of your shingle by three-quarters of an inch or something and if they are not familiar with the trades they might not even know that that’s a vent,” he said. “Some people will have five or six regular vents. Some people will have a power vent so then if you have a power vent, it’s actually like a fan and a motor forcing the air out of the attic so you may not need as much venting with a power vent.”
Not much can be done on the interiors of homes to prevent water damage from ice dams, he said.
“As long as you have proper venting and proper insulation, there is not a lot else you can do on the inside part of it to prevent it,” he said. “A good thing would be, if you know you are getting a lot of snowfall and everything, to get up on your roof and clean those valleys and stuff and get them cleaned off so when the sun does shine, it will actually melt it, not melt it and have it refreeze.”
Hillerud said to use a roof rake or something designed to get the snow off without scraping the shingles.
“You can do more long-term damage trying to get the ice off and you can create a problem or speed up the wear and tear on your shingles,” he said. “It is best to try to handle that with a roof rake or something that you can get at from the ground without having to get up on the roof and have.”
Krueger said keeping gutters clean also helps prevent ice dams.
Products such as Elastomeric roof coating could help prevent water leaks from ice dams but it is unsightly because it goes on either white or black, Krueger said.
“It could potentially seal the shingles together so the ice wouldn’t be able to creep up underneath them but ice is very powerful,” he said. “When it wants to move things, it will move things.”
Krueger said tin roofs are probably less susceptible to ice dams. He said tin roofs last for a long time whereas shingles start to curl and go bad after about 20 years.
But tin roofs could be unsightly on a house if they sustain any hail damage. He said tin roofs are meant more for certain lake cabins and shops.
“The right house it looks OK on, but to me, I think shingles look better on a home,” he said.