Expert: Daniel Humphrey - 2/26/2009

Question
We had a timber frame house built, it is less than a year old.  We have experienced cracked and heaving basement flooring, ice damming and interior leaking due to a build up of condensation, we are told.  This has resulted in ruined paint, ruined hard wood and don't know where the damage will end with our experience.  There was no air space left in between the insulation and the roofing system.  This whole build was a disaster from get go.  Is there a way to fix this properly - what are the options.  It's been very interesting having people over while stepping over 20 different buckets throughout the house.  It is shameful really.

Answer
Dear Tanya

That must be a terrible disappointment for you. I wish I could visit and help you out. I am very familiar with the challenges you're facing and I have solutions.

Since you've identified the problem as condensation, you will need to work on keeping the humidity down during the winter months and preventing warm, moist air from contacting any cold surfaces.

The first thing I would recommend, which will help immediately is putting in a balanced heat-recovery ventilator (HRV). The fresh, filtered air that it brings into the house is wonderful and will help keep the humidity down. You can also balance the HRV so that there is a slight negative pressure in the house to keep from pumping warm air into the air leaks.

In the meantime, try to keep the humidity down when you cook and bathe.

Once you reduce the humidity, you can work on sealing the air leaks that allow moisture to get to cold surfaces.

You have mentioned that the roof has no ventilation. This in itself is not usually a problem, as long as no air can get through the surface. Wood T&G that is not backed by sheetrock is totally ineffective at stopping air movement. Perhaps you have that. If you have sheetrock, then sealing around the edges, sealing all penetrations, and painting with two coats of vapor retarding paint will help the ceiling at least.

The worst case scenario would be to remove the roofing and add another 10 to 16 inches of  ventilated air space, drawing air from the eaves and allowing it to move out the ridge. In some ways, this is less obtrusive than working from the inside and gives you better results. The principle you would use is to install a vapor/air barrier on top of your existing roof sheathing, then add twice as much R value as you have already, and then the several inches of air space.

For your basement condensation, you will need to get a good ventilation system there as well.

Write back again if you have further questions. I'll be answering questions here for another month or so, before I go work at a remote site. You can solve these problems with a deliberate plan of action. Hang in there.

--Daniel