Replacement Windows: Should You Choose a Pocket Sill or Sloped Sill?

With the warmer months just around the corner, now is a good idea to take stock of the windows in your house and make sure they are functioning at their peak. We have published an article on when it is time to replace your windows, which you can read here. And, if you find your windows do in fact need replacing, now is one of the best times to do it. Why? As we all know, the COVID-19 pandemic means we have to stay indoors for the time being, which also means we want our homes to be as comfortable as possible. New windows not only ensure your home is as pleasant to be in as possible, but they can also help lower utility bills by ensuring your air conditioning unit is not working overtime. Air conditioning units work harder than they need to when you have improperly functioning windows, which can allow conditioned air to escape outside, and let outside air in. 

One of the biggest decisions is choosing between a pocket sill or sloped sill. That is why in this article we will be discussing the differences between a pocket sill or sloped sill and which one we recommend when installing replacement windows. 

What is a Sill and Why is Drainage Important? 

The sill is the bottom section of the window.  This is where all the bugs, dust, dirt and debris accumulate over time. It is the area you need to vacuum when you open your windows for the first time when the weather warms up.

When choosing a window sill, it is important you choose a sill that has a good drainage pathway away from the window. The gutter type of design in a pocket sill window relies on a series of weep pathways to remove accumulated moisture out of the window frame. However, these weep pathways are known for their high failure rates because they often become blocked by dirt, debris and bugs. When this happens, the water has no place to drain out, so the water is forced into the home. Conversely, a sloped sill window does not need to rely on any weep holes to drain out accumulated moisture, making it a significantly more fail-proof design compared to pocket window sills.

Pocket Sills 

Pocket sill windows are a deep sill (frame) design that completely surrounds the bottom edge of the sash in the closed position. The advantage of having this particular design is that in some limited  cases you will get better air infiltration and more glass to your window. The biggest disadvantage, however, is that the sill looks and acts like a gutter for your window. Not to mention, over time it will begin to fill up with dirt and debris, which more often than not leads to structural problems and costly repairs. While pocket sill windows can be lovely to look at, the structure of the frame may not hold up over the lifetime of your windows. 

Sloped Sills 

Sloped sill windows are exactly what they sound like: they feature a slope at the sill and they flush the dirt and debris out every time it rains. This design uses gravity to send water out of the sill of the window. One of the biggest advantages of a sloped sill window is that there is very little to almost zero maintenance required, and therefore there is less chance of structural erosion of your window frame over time. Furthermore, constructed sloped sill windows have the same if not better air infiltration rating than the glass of a pocket sill window. 

Which Should You Choose - a Pocket or Sloped Windows Sill? 

The experts at t WoW prefer a sloped window sill,When it comes down to it, modern designs of sloped silly windows  outperform the majority of pocket sill windows when it comes to design pressure (e. strength), air infiltration (i.e. airtightness) and visible glass and require very little to no maintenance.

If you are unsure which window design is right for you, WoW is currently offering virtual consultations, so get in touch today for our expert opinion.