Home>Discussions>INTERIORS>Living Areas & Workspaces>Moisture Entering Attic Through Soffit
6 posts / 0 new
Last post
stadium
Moisture Entering Attic Through Soffit

I live in the Seattle ,Washington area. We have been chasing a moisture problem in out attic. We recently had the roof replaced including 20 sheets of plywood due to molding and rot. When the roof was done we had new bathroom vents installed eliminating the the way they had been done running out the soffit and taking then through the roof instead. We also had more roof vents install at the ridge doubling the number of roof vents. After getting this roof done we had new insulation blown in and baffles installed. The roof and insulation were done by reputable contractors with the highest recommendations on Angie's list so we have no reason to believe they have missed something. About 3 months after the work we looked in the attic and were horrified to find on one side about 3 sections of plywood with full mold growing just near the baffles. It's localized within 4 to 5 rafter sections but doesn't extend upward toward the ridge much past the baffles. Everything in our attic is sealed tight and a beautiful job done on the insulation. So we are wondering if this moisture could be entering through the soffits at one area of the house where the dryer vent was relocated some years before we move into our house. The vent is approximately 9 to 10 feet below the soffit area of the roof where the new mold has accumulated. It exits under a deck. I have seen huge plums of steam coming from under the deck in the winter whenever we dry clothes. This could be as many as a dozen times in a week. My question is: Could this dryer vent have been a major contributing factor all along? After all we had done the dryer vent was the only thing not changed. And the mold/moisture recurrence seems to be in alignment with the area where the dryer vent exited the house about 9 to 10 feet below. I really think my wife connected the dots so this weekend I re-routed the dryer vent and now it exits the house at the gable end away from any soffits. Hopefully this was the last obstacle to keeping moisture from entering our attic. I get physically ill in my stomach when have to enter the attic of this place anymore for fear of what is going to happen next. Any ideas on drying out what moisture has accumulated again would be appreciated.

dj1
Re: Moisture Entering Attic Through Soffit

Wet insulation has to be replaced. With proper ventilation, slightly wet wood can be saved, if you act immediately, still not guaranteed.

stadium
Re: Moisture Entering Attic Through Soffit
dj1 wrote:

Wet insulation has to be replaced. With proper ventilation, slightly wet wood can be saved, if you act immediately, still not guaranteed.

ok act immediately do what immediately??? act is not specific enough

keith3267
Re: Moisture Entering Attic Through Soffit

I assume you have soffit vents. The quick answer would be to remove or block the soffit vent or vents directly above the drier vent so that steam cannot enter at this point. Caulk and paint the soffit for about 6' to each side of the drier vent so that the moisture cannot enter at this area.

Another possibility is to extend the drier duct all the way to the edge of the deck and put the vent there. This would help extend the life of your deck as well.

To address the current mold situation, there are several products that can not only get rid of the current mold, but treat the wood to keep it from reoccurring. Bleach and water at a 1:10 ratio max, 1:100 min will kill the current mold but will not prevent its return.

Antifreeze, ethylene glycol, can be sprayed on and it will kill the mold and prevent its return. Wear a mask or respirator as this stuff is toxic. One ounce will kill you but you are unlikely to inhale an ounce of the stuff, but wear a mask anyway. Once it has soaked into the wood, its not a problem any more.

A sodium borate solution (disodiumoctaboratetrahydrate) like Timbor will not only kill the mold and prevent its return, it will also discourage termites and other insects. You can find it by Google for it or make your own. Two cups Boric Acid, three cups Borax (20 mule team) mixed in gallon of hot water. To really make it more effective, instead of water, use 1/3 gallon of antifreeze and 2/3 gallon of water. Again, wear protection when using antifreeze.

All these solutions can be applied with a garden sprayer. A pump type sprayer works really well and is pretty cheap.

dj1
Re: Moisture Entering Attic Through Soffit
stadium wrote:

ok act immediately do what immediately??? act is not specific enough

You want to dry the area ASAP, so "act immediately" means improve ventilation now. One way of doing it is to place a fan there and run it.

Still lost? get a contractor to help you.

MtMan54
Re: Moisture Entering Attic Through Soffit
stadium wrote:

I live in the Seattle ,Washington area. We have been chasing a moisture problem in out attic. We recently had the roof replaced including 20 sheets of plywood due to molding and rot. When the roof was done we had new bathroom vents installed eliminating the the way they had been done running out the soffit and taking then through the roof instead. We also had more roof vents install at the ridge doubling the number of roof vents. After getting this roof done we had new insulation blown in and baffles installed. The roof and insulation were done by reputable contractors with the highest recommendations on Angie's list so we have no reason to believe they have missed something. About 3 months after the work we looked in the attic and were horrified to find on one side about 3 sections of plywood with full mold growing just near the baffles. It's localized within 4 to 5 rafter sections but doesn't extend upward toward the ridge much past the baffles. Everything in our attic is sealed tight and a beautiful job done on the insulation. So we are wondering if this moisture could be entering through the soffits at one area of the house where the dryer vent was relocated some years before we move into our house. The vent is approximately 9 to 10 feet below the soffit area of the roof where the new mold has accumulated. It exits under a deck. I have seen huge plums of steam coming from under the deck in the winter whenever we dry clothes. This could be as many as a dozen times in a week. My question is: Could this dryer vent have been a major contributing factor all along? After all we had done the dryer vent was the only thing not changed. And the mold/moisture recurrence seems to be in alignment with the area where the dryer vent exited the house about 9 to 10 feet below. I really think my wife connected the dots so this weekend I re-routed the dryer vent and now it exits the house at the gable end away from any soffits. Hopefully this was the last obstacle to keeping moisture from entering our attic. I get physically ill in my stomach when have to enter the attic of this place anymore for fear of what is going to happen next. Any ideas on drying out what moisture has accumulated again would be appreciated.

Hi, If the miosture is entering over the deck, then you have your answer. The moisture is exiting through the door every time it is opened. Thanks

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.