A guide for homeowners doing renovations.

Specifically - Hiring Contractors, How to Save Money and Disaster Prevention.


OK.  This is important.  So the moisture is the problem but what's causing the moisture?

***Flowchart - Coming Soon***

Before I really get into the troubleshooting, you're going to need to know a few things.

We are trying to find a dew point.  It's the point at which the hot air meets the cold air with the humidity typically higher for some reason. (ie: bathroom showers, kettle boiling, fish tanks etc.)

Here's the process of troubleshooting:

STEP 1. Checking for Window Argon Seal

Check for condensation or frost in between the panes If there is condensation on the inside, then the argon fill seal is broken and your window might be covered under warranty.  To my experience the Argon seal breaking has a warranty of 2-5 years.

Keeping your bathroom fans' vents
clean goes a long way!

STEP 2. Check wall insulation/penetrations for air leakage via conduction through the wall or through a breach in the vapour barrier

If there isn't any, then check by feel(or use a surface heat thermometer $30) to see if the wall under the window is cold (properly insulated) look for areas near plugs for cold air in the winter, hot in the summer.  You might have a floor register that is mixing with outside air and creating that dew point OR it might not be causing enough air flow in your home(see #3).  Typically, if it's JUST the floor register and your walls are well insulated, the condensation in the wintertime is from the Argon seal breaking.

STEP 3. Checking air flow - lack thereof

If none of those cases are present then more than likely you have a humidity problem and poor air flow.  Also as mentioned, that can be caused by blinds, curtains and an unintentional "passive solar/heating effect." I suspect your humidity is too high given your airflow.  You may need a dehumidifier.  Check your bathroom fans too...Have some fish tanks?

STEP 4.  Checking temperature consistency in each room. (To figure out if it's one window vs all windows or one room vs all rooms)

Try opening all your vents for a while, enough that your furnace is working to heat each room consistently, grab a $30 surface temperature gun or digital thermostat and check to see if your rooms of a single story are all the same temperature, then check the room with the window.  (might as well point the surface detector at the wall and check a reading for #2 relative to other walls.)

If it's all windows or all rooms, you have a furnace/heating/air circulation problem. Call the HVAC guy.  If it's just one window or room and you're sure it's not #4, then it's #5 below.

STEP 5. Unlikely but poor window installation - specifically between the rough opening (R.O.) and the window.

In some cases, the perimeter of a window installation can be prone to being poorly insulated: either lack of acoustical sealant on the V.B., or no insulation between the window and the rough opening.  Pop the casings off and check, maybe spray some low expansion spray foam in any gaps.  Use silicone caulking around the perimeter if you can't spray foam.

STEP 6.  If you haven't solved your problem, I'd like to know! 

Email me your situation and I'd be happy to learn with you.

PLEASE, DON'T REMOVE SIDING - You don't need to unless you're getting damage from water and the above situation is dew point related - not water shedding related.


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