There are several telltale signs of a bad window installation that homeowners should learn to spot.
It’s something we often discuss with homeowners in our Raleigh, NC area window supply store.
In this post, we’re sharing the top 7 most common signs of a bad window installation.
What are the Signs of the Best Window Installation?
Before we outline the clues that let you know a window has been poorly installed, let’s first explain what makes a good window installation.
It’s important to know this, because the best, most energy efficient window will eventually fail if it is poorly installed.
To be properly installed, a window must be:
1. Plum
2. Level
3. Square
A plum window has sides which are perfectly perpendicular to the level sill.
A level window is one that is in level across the span of both the sill and the top of the frame.
For a window to be square, each corner must be 90 degrees. The window should not be ‘racked’, meaning that one or more angles are less than 90 degrees, and one or more angles are more than 90 degrees.
Additionally, a well installed window will allow for natural expansion and contraction.
This is especially important here in central North Carolina, where we can easily see 70° temperature swings in the span of a few days. These changes in temperature, as well as the humidity we experience in the Raleigh area, mean lots of expansion and contraction in materials like wood, vinyl, PVC, and aluminum. Your windows must allow for the natural expansion and contraction that will impact your home. Expansion and contraction affects:
- Your home’s exterior (brick, siding, etc.),
- Your window frame,
- Your window’s casing or moulding, and
- The caulk used as sealant
With so many individual aspects affected, it’s easy to see that a window which isn’t designed to factor in expansion and contraction is a window that will fail.
There are two ways that a good window installation accounts for expansion and contraction.
1. By having a correct expansion joint. An expansion joint is the space left around the window during the installation process. This gap between the window frame and your home’s siding allows both materials to expand and contract with the weather. Without this, a window may butt up against the siding when it expands. This can cause the window to bow and warp, because it didn’t have ample room to expand. We recommend an expansion joint of 5/16 inch for most projects. Of course, we may recommend something different for your home depending on the specific materials used.
2. By using excellent, silicone-based caulk. The ‘exterior’ caulk available at most big box home supply stores does not adequately flex based on the weather. Over time, it tends to become brittle and crack, making your windows vulnerable to gaps, rot, and other issues. Many of the signs of a bad window installation that we’ll detail below are caused by installers using the wrong caulk. A good window installation uses a strong, flexible, silicone-based caulk that will expand and contract to allow natural movement.
Signs of a Bad Window Installation
Now that we’ve outlined the hallmarks of a well installed window, let’s outline what are the 7 telltale signs of a bad window installation.
1. A Window That Doesn’t Open is a Sign of a Bad Window Installation
If a window won’t open, it means that the moving parts of the window can’t operate, because the frame can’t glide in the frame.
Generally, this reflects that the window was not plumb, level, and/or square when installed.
2. A Window That Doesn’t Lock is a Sign of a Bad Window Installation
Similar to a window that won’t open, a window not locking means that the lock and keeper are no longer in alignment.
This reflects that the window is not plumb, level, and/or square in the rough opening.
3. A Window That Lets in Rain, Wind, Dust, or Bugs is a Sign of a Bad Window Installation
If you stand near a poorly installed window, you may feel a draft. Or worse, you may see water or even bugs coming in through a closed window.
4. A Window That Won’t Stay In Place is a Sign of a Bad Window Installation
If you move the sashes on your single or double hung window (LINK), they should stay in place.
If you see them creep, or even worse, drop quickly after you move them, that’s a telltale sign of a bad window installation.
5. A Window Sill That Isn’t Level is a Sign of a Bad Window Installation
If you look at your window with either the sash slightly raised or the casement slightly cranked out, you should see an even space between the sash and sill.
In the construction industry, this space is referred to as ‘The Reveal‘.
This distance should be the same across the span of the window. If it’s not, it’s a surefire sign the window is somehow out of alignment, and is either bowed, crowned, or angled.
6. Poor Caulking is a Sign of a Bad Window Installation
Caulk seals the gaps between the frame and the moulding or casing around the window. Caulk is also important to allow the window space to expand and contract based on heat and humidity.
A well-done caulk job will not be noticeable. A poorly done caulk job, with globs and beads of caulk in some spots, and thin or tearing caulk in others.
While this may seem to just be unsightly, over time, this inconsistent caulking can lead to many of the issues we’ve already described. You may notice wind or moisture entering through the frame. Or, you observe some of the functioning issues we’ve described, like trouble opening, latching, or staying put when opened.
Or, the window installer may have used the wrong type of caulk. While acrylic caulk is readily available and relatively cheap, over time it dries and becomes brittle, and thus doesn’t move with the window. In some cases, this can cause water leakage issues over time.
We recommend a silicone-based caulk, which is a more durable and elastic product that will move with your window for years to come.
7. A Window That Doesn’t Have a Proper Expansion Joint is a Sign of a Bad Window Installation
An expansion joint is the space left around the window to account for changes in materials around the window as they expand and contract with the weather.
For most window projects, we recommend and install an expansion joint of 5/16 inch.
We frequently see windows installed with either too large a gap for an expansion joint, or with no space at all.
Too large of a gap will result in caulk breaking down over time, because it is filling too much space to be functional.
On the other hand, too small of a gap will cause the window frame to bow when it tries to expand but has no room to do so. This leads to many of the issues we’ve described above.
Summary
As you can see, there are many factors that go into an excellent window installation. When it’s time to replace your windows, you want to work with professionals who are meticulous and exacting about every aspect of your project.
We at the Window Works Co. have installed windows for thousands of satisfied homeowners in the Raleigh, NC area (check our Google reviews!). We’d love to help you, too!
Just fill out the form below to tell us about your project today.
