Window Sills
Window Sills are a Very Important Part of the Masonry on Your Home.
The Purpose of a windowsill is to protect the masonry below it, by moving water away from the from the wall. The windowsill is part of the wall not the window.
When the rain water runs down your window and on to the slope of the window sill, the window sill moves the water away from the face of the brick under the window. On properly installed window sills, a strategically placed drip edge 5 cm from the face of the masonry wall forces the water to fall to the ground without touching the brick under the window.
Problems Caused By Water
Water getting behind or below the window sill can cause a variety of problems, including;
- Rotting of the wall behind the window sill,
- Spalling of the brick below the window sills,
- Inadequate protection for the window frame.
All of this compromises the integrity of your home.
What Causes Window Sill Damage?
Most of the damaged windowsills in the Ottawa area are caused by Home builders choosing to use bricks instead of a proper stone windowsill. Bricks are porous and absorb water. This eventually leads to spalling and the deterioration of the mortar between the bricks on the windowsill. Brick windowsills requires a significant amount of maintenance, and do not properly draw water away from the window, and any masonry below. The reason bricks are used for windowsills is because of cost. Although the price of installing a proper stone windowsill during the initial construction is relatively low the home builders cut corners by using what is readily available bricks, instead of ordering proper windowsills.
Oxidizing of steel re-bar in concrete cast windowsills is another problem. When steel re-bar in windowsills do not have enough concrete surrounding it, moisture can sometimes penetrate the concrete and oxidizes the steel re-bar. As the steel re-bar oxidizes it expands, causing the concrete to crack the windowsill, subsequently allowing more water to enter.
Maintenance of Window Sills
The most common of problem with windowsills is maintenance. All windowsills need regular maintenance. From a one-piece precast windowsill, multi-section windowsills or a hand carved Indiana limestone windowsill, maintenance is key. The masonry joints around the windowsills are continually being soaked and weathered. Re-pointing around this area with the proper mortar will save you thousands of dollars.
Moisture behind windowsills causes serious problems for a homeowner. Rot sets in behind the wall, and mold begins to appear. As you see symptoms of rot around the window, it is too late, a major repair is already necessary.
Aesthetics of Windowsills
A Rock face, Arriscraft windowsills also acts as a trim to your windows and adds an air of sophistication to the overall aesthetics of your home. This cannot be understated. The change is phenomenal.
Brick Windowsills require constant maintenance and do not draw water away from the house.
Brick Window Sills require constant maintenance and don’t draw water away from the house.
The Same Window With Proper Stone Sills installed. These Window Sills draw water away from the window and brick below.