Cold Weather Prompts Investigation into Potential Problems with House

There’s a nip of fall, just a hint in the air. That means remembering what winter is like, including how your house has been holding up. Do you remember mopping up or putting out cans and buckets to catch drips? If so, now is the time to learn what’s really going on and do something about it.

Everyone assumes that when water comes into a house that there’s something wrong with the roof. They think rain or snow melt is getting through. That’s understandable, and even possible. Home buyers who are new to Alaska assume they will have a roof inspection. They are used to rainy climates where a hole in the roof means water in the house. If they are smart, however, they won’t stop their inspection at the outside surface of the roof.

Condensation is the more common problem in Alaska. Moisture is everywhere in a home. Where it collects against a cold surface it condenses like water on the outside of a glass of ice water. In a house, moisture gets into an attic space, even though there’s supposed to be a vapor barrier of visquine between the sheetrock and the wall studs, the ceiling joists and the roof trusses. Once there, it needs to ventilate out, or it can collect under the roof deck, condense, and start dripping back in.

There’s no keeping all of it out. In many older homes the vapor barrier is not continuous, as the current code requires. Roof systems that have a glu-lam beam halfway down the roof line are offenders. The visquine may only run up to the glu-lam. Moisture gets past it there, condenses, then runs back down the beam. The homeowner ends up with buckets here and there. It happens after a longer cold spell that’s followed by a Chinook, one of those midwinter warm storms off the Gulf of Alaska that melts everything.

Other paths for moisture into an attic include older recessed can lights. Those designs sometimes don’t have proper protections to keep moisture from getting past them. Moisture also follows vents from bathrooms, the kitchen and the laundry that penetrate the ceiling and the roof. Venting the drier into the attic or crawl space is a no-no, but some home owners have jury-rigged it that way. Bathroom fans are notorious leakers. If the fan is over the commode, it’s a real pain to be dripped on in the middle of the night when you would rather be left alone.

The cures for these kinds of ventilation problems can be simple or very complicated and expensive. Sometimes the only thing wrong is that insulation is blocking the soffit vents. Pushing it back and establishing baffles to keep it there is sometimes all it takes.

The next level of complexity is adding ventilation where it is missing. Cutting in soffit vents or making them bigger is not very complicated carpentry. So is cutting a hole in the roof (yes!), a long opening along the ridge, actually, for a ridge vent through which the moist air escapes.

Some roof systems can’t be ventilated so easily. The whole cavity may be packed with insulation. If moisture is getting in there, condensing, and dripping back in, the problem doesn’t fit itself. Eventually the roof framing members rot and the roof caves in on you. The fix usually involves taking off the entire outside of the roof, the shingles (or shakes) and the plywood. The contractor inspects and replaces insulation as required. The contractor inspects and repairs the vapor barrier. If there is rot in any of the framing it can be replaced or additional rafters can be sistered along side the defective ones.

Finally, the contractor expands the size of the cavity by building up the height of the roof trusses with additional lumber. Then when the new plywood and roof covering goes on there is a gap for air movement above the insulation. Air vents are established along the eaves where dry air enters, runs along the underside of the roof deck, and gets out through a ridge or other exit vents.

The brighter side is that a major undertaking of this sort provides an opportunity to address other design deficiencies. Recent code revisions require builders to establish ice and water shields under the shingles for three feet above where a vertical wall intersects. Even when an ice dam forms, it can’t get past where the shield is. When it melts against the warmer roof surface it can’t get to the plywood, down to the insulation and back into your house.

Replacing the roof deck also ensures that valleys where roof lines intersect will be properly flashed. These valleys in some roof designs are notorious offenders, where ice experiences freeze and thaw cycles and works it way into the home.

If any of this sounds familiar, get going on the project now. This is a busy season for small contractors and the larger roofing companies. The Anchorage housing stock is aging and these problems are coming to light every day. Lots of homeowners want this kind of work done now. They don’t want the roof off in October when the first snow hits. There’s a terrific demand for contractors now, and as little as eight weeks to get all this work done.