Attic Inspection ventilation

Will your home inspection reveal attic moisture issues?

More and more we are finding attic moisture issues and mould during our home inspections. Obviously, this is never a good thing – whether you are buying a home or not! So how do moisture problems occur, and what can be done to prevent them?

Moisture can build up a couple of ways:

1)     Leaky roof. It goes without saying that you should replace your roof when you notice the material disintegrate.  It is costlier to deal with all the issues that occur once a leak starts then it is just to replace a roof. However, leaky roofs aren’t the culprit as much as you would think.   

2)     Lack of ventilation in the attic space is the most common cause, and the one we will focus on in this article.

In general, your venting should resemble this illustration courtesy of Carson Dunlop.

In most cases, a home inspection will reveal that there is inadequate soffit venting. Either because it never existed, or it has since been blocked by the addition of new insulation. If you have insulation blocking the soffits ensure it is cleared out and adequate blocking installed to keep it in place. Insulation contractors sometimes install stryofoam forms – but these may not do the trick. The ideal solution is cardboard or similar stapled to the roof rafters, to hold back all the insulation.

If you do not have any soffit venting in the first place consider having your roofer install intake vents along the lower portion of your roof (approx. 1’ above the insulation.) 

Some, may also suggest a whirlybird be installed, but use caution. There are plenty of articles out there about how these devices will depressurize your attic, causing excess heat loss when the wind is blowing, and not provide adequate ventilation when there is no wind.

Finally, these solutions work only if you catch them soon enough – if you already have mold in your attic you will need to have it professionally remediated, and most likely have the sheathing replaced during re-roofing, and then follow the steps above.

If you would like to know more about how to make sure your attic is moisture free, email or call our Home Inspector today at 250-877-0431.

Leave a Reply

Your email address will not be published. Required fields are marked *