Townhomes and Attic Rain 101

Townhomes and Attic Rain seem to almost go hand in hand these days. We are seeing a high percentage of reports of varying degree of moisture issues in attics, particularly in newer townhomes. Why is this and what can be done about it?

Firstly, attic rain is a phenomenon we see here in Alberta during our cold snaps, that exceed -30 degrees Celsius. I mean its gets COLD. When moisture gets trapped in attics, it will freeze against the interior of the roof. Once it warms up, it thaws and starts to drip, giving the appearance of rain inside your attic space. This can create water damage to the ceilings below.

This is a result of high moisture content within a home that has no where to go. This isn't so much an issue with older homes because they are not built to the same airtight standard as newer construction and can naturally ventilate through drafts within the home. Newer homes are generally seeing such air tight standards, that the home requires an HRV (Heat Recovery Ventilator) to exchange stale indoor air with exterior air to keep the interior environment "fresh". Our homes environments are now being regulated mechanically, so when we introduce moisture through a humidifier system, we count on the HRV to keep it moving around the entire home. This works for the most of the home, but attics are not part of the designed area that we are processing and we use roof vents to assist with naturally "airing out" the attic. The problem is, when its -30 or -40 outside, its typically very stale cold fronts with little to no wind to help air out those attics, and the moisture freezes almost instantly to anything it can get a hold of.

Roofers can make a pretty decent living recommending additional roof vents to till the cows come home, which do help, but we as homeowners are the first line of defense.

• Turn your humidifiers down.

• Leave your bathroom fans running for an extra 20 minutes after a shower.

• Check your attic for disconnected vents, dryer vents are a common issue

These are easy fixes that we are entirely capable of doing if you understand how your mechanical system works. Reduce the moisture in the home, and increase ventilation will solve the problem 9 times out of 10 and with a basic orientation of your system while you have your home inspection done, can give anyone the tools to better manage their home.

If condo corporation has your attic listed on common property but you are leaving your humidifier on high (which does make a comfortable environment), you would actually be responsible for the water damage caused, which can be in the thousands. If we read in your condo documents that select units have issues, its likely a user issue. If the entire complex is affected, it could be a design issue which the corporation would then need to start looking at resolutions (in most cases).

Townhouses are certainly more low maintenance and hands off than detached properties, but that doesn't mean we cant let our guard down in the extreme environments we live in. With 40 degree temperature swings we see, there are some things that are nearly impossible to design ourselves out of and we simply need to be aware. Ask your home inspector to walk you through the operations of your mechanical system or hire a HVAC contractor to do a once over on your equipment after moving in and give you some advice to manage your equipment during extreme cold snaps. It could save you thousands, come next winter.