One of the most common areas for a window leak to first of appear under a window it is on the base board. You may notice swelling in the area or paint bubbling under the window. The paint bubbling is generally due to moisture but if it’s a straight crack it may be a join in the drywall that has moved as the house has settled or if there has been general settlement in the property.
If the skirting/base board has swollen up it is a sure sign that there is moisture behind the walls, especially if at an isolated area below a window where the swelling has occurred.
So how do you determine where the window leak is getting in, and how much damage has it done?
Many windows are not sealed where the outside cladding meets the window frame, and water will drive into the side of the window frame especially when it’s raining and windy. Seal any type of window leak with high quality sealant otherwise water may be running down the side of the frame and directly down into your wall, wetting installation and damaging timber framing in the process.
The other area where the water may be entering around the window is through the head flashing. The head flashing is a piece of Z shaped metal across the top of your windows that prevent water getting around the top of the actual aluminium joinery itself. Some builders do not finish off the details of windows correctly and this is a major window leak problems for many home owners, yet so simple to fix.
Window Leak Through Joinery
After conducting alot of window leak testing, one of the biggest leak causes with windows is the aluminium joinery mitres. These other small 45° angle joins in the corners of windows and the slightest bit of movement can cause these joins to open and become the start of a destructive window leak. Water can easily enter a around the window frame. Get your windows checked with a moisture metre under the windows and around in case the leak is actually coming from further up the wall. Get a thermal imaging camera into your house also to help find the window leak.