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What is a Window Sash

What is a window sash

Windows are important parts of our home. Protecting us from weather elements, they can be opened for a breeze on a nice day, and they provide security in our home.  Did you know that there is a part of the window called a window sash?

It is not a decoration or fabric like a sash you might wear. What is a window sash? The part of the window that slides up and down and holds the panes of glass together.  Attaching to the house, it fits inside the frame of the window.

Let’s take a look at why this is important, how to tell if there is a problem, types of windows and materials, how to know when to replace the windows, why replace them, and maintenance.

Why This is Important

The window sash is very important on a window as it holds the glass in place. Fitting into the window, the vertical and horizontal frames are reinforced, multi-chambered, and infusion welded so they don’t distort in shape.  If they distort, they will not work properly and will allow water and the outside elements in.

How to Tell if There is An Issue With the Window Sash

If the window gets stuck while opening and closing, there could be a problem with the window sash.  It may indicate that there is an alignment problem and you can get this fixed. 

However, if the windows are older, you may want to think about replacing them instead with high-efficiency windows that will cost you money, but save you money in the long run.

Types of Windows

Double Hung Window
Double Hung Window

Double Hung Window

This is a popular type of window available in wood, fiberglass, and vinyl.  Double hung windows ventilate well and are made of two vertically sliding sashes. This allows the homeowner to open the top sash or bottom sash or both.

Double hung windows also have a screen on them, along with a weep hole in the windowsill to allow the water and condensation to escape.

Slider Window

Slider Window

This type of window opens and closes horizontally.  Sliders are a lot like the double hung window but horizontal.

Casement Window

Casement Window (Crank)

This type of window comes in wood, fiberglass, or vinyl and uses a hand crank to open it.  This is different than the way the double hung window opens.  It opens away from the house to allow the breeze to come in.  It is important to be careful with this window as a high wind can move the sash and break it off.

Types of Materials for Windows

Wood Windows

Wood Windows

Older homes may have wood windows and they often will have problems with rotting, shrinking, or swelling.  These things can make them difficult to open and close and be safety issues.

If you have this type of window, you may want to think about replacing them so they work effectively.  The good news is now there are “wood look” type vinyl windows so you can still get that wood feel.

There are also wood windows that are manufactured but it will depend on the area in which you live if this is a good investment.  Below are the pros and cons of wood windows, if you are interested.

Pros: Wood windows are energy efficient, add value because they are wood, and still available if you prefer those to vinyl.

Cons: Wood adds about 25% more to the expense of replacing versus vinyl.  Also, since it is wood, painting and sealing are often needed to keep the wood from rotting. Additionally, wood windows can rot faster in various climates.

Vinyl Replacement Windows

Vinyl Replacement Windows

These are the best types of windows out there now.  Vinyl replacement windows are made from high-quality PVC, require little maintenance, easy to clean, and are durable. They are cheaper than wood windows, lots of color choices, and have the look of wood without the expense or worry of rotting.

Cost: About $300 installed and up into the several thousands.

Cons: Color can fade in the sun and heat.  Make sure you use a reputable dealer as not all vinyl windows are equal in durability.

Aluminum Windows
Old aluminum windows from the 1960’s

Aluminum Windows

Many homes in the 1960s were built using aluminum-type windows.  However, it has been discovered that they present problems with the aluminum oxidizing, which means it develops a thin film on it.  These types of windows also are prone to sweating and condensation.  Even though they are not made anymore, there are places that sell replacement parts.

Replacing the Window Sash

You can replace just the sash, however, if your windows are older, you may want to consider replacing the windows instead. It is a good idea to ask a professional to take a look at them and make a recommendation.

Here is a video that shows you how to replace the window sash.  If you decide it is too much to do, call a professional.

How to Know When to Replace the Windows

Draft From the Window When it is Closed

This could be due to poor insulation or faulty seals and you can have a professional look at them to make a recommendation.

A drafty window can also cause the HVAC to work harder, which will raise your electric bill and possibly cut some years off of it. Additionally, you have a better chance of rainwater getting in.

You Hear A lot of Noise From Outside

Single paned windows are very thin and don’t keep the noise out.  Double and triple paned storm windows are made with argon gas and are able to keep the noise out better.  They also have a sash that helps create a tight seal.  If you don’t have these in your home, it will be a good investment.

Window Frames Are Soft, Chipping, or Have Water Damage

This means that water has already started entering the home and the windows are probably sagging.  Unfortunately, they may be beyond repair and need replacing.  Call a professional to take a look and to make a recommendation.

If you notice the window frames are doing this, you will want to take a look to see if there is water in the home as this can cause mold to grow. 

Also, check the walls to see if there are any water spots or hire a professional to use thermal imaging to make sure the water on the wall is just from the window and not an additional issue.

Windows Are Difficult to Open, Close, or Lock

The windows could be off-balance or have swelling or shrinking, as mentioned above about wood windows.  This is a problem as it is a safety issue and needs to be looked at right away by a professional.

Condensation building inside the windows

Condensation Building Inside the Windows

When this happens, it indicates that the seals are gone and air is leaking out. Unfortunately, it also means you will need a new window.

Why Replace the Windows and What to Consider

You Can Find a Reputable Company and Have a Peace of Mind

You will have choices of various manufacturers, energy efficient windows, and the right people to install the windows properly. If you are having issues with the windows, a reputable company will put you at ease when they install news ones for you.

Use Google business and other reputable sites and find reviews on the company.  Check the BBB, even though some businesses don’t register there, many do and you can find out if there are problems with the company.

Structural Reinforcement

Structural Reinforcement

The sashes will be amazing in your new windows and will provide safety in the home from break-ins and also weather makers.

New Windows Will Be Easier to Clean

Updating the windows in your home will make it easier to clean them. 

Save Money

Even though you will be spending money, you will find that the new windows will be energy efficient and save you money over time.

Maintaining the Sash

Annually, check around the sash to make sure there is no wood rotting, warping, mold, mildew or deterioration.  If there is, there is an issue and you need to call a professional.

Next, move the window up and down and lock and unlock it.  If it seems to move and lock with no issues, then the window is good.

Other Maintenance to Think About

When inspecting your windows, take a look at these other areas:

Window AC unit

Window AC Unit

If you have a window AC unit, you should be performing maintenance on it at least once a month to keep it functioning properly. This is also a good time to make sure the window is sealed properly and it opens and closes with no problem.

Weep Holes

As mentioned earlier, weep holes are essential in windows to let the water drain so it doesn’t go into the walls.  Check out this video on how to maintain them in windows

When it rains, we need to make sure the gutters are clean so the water flows across the top of the house and down through the downspouts. 

Remember to keep the downspouts 4-10 feet away from the home so there is no accumulation of water.  If the gutters are full of debris, the water can flow over the edges (skipping the downspouts) and into the house or create puddles near the basement.  Then, the water can get into the home.

If you have eaves on your home, check them regularly to make sure there are no holes and seal them regularly. 

When to Call a Professional

Call a professional when you have questions about your window sash or if you are having issues with your windows.  They are trained and can give you good advice about replacement or repairing. 

Other ways they can help is with recommendations on the type of window that will be best in your home depending on where you live and the climate.


Windows are expensive but it is necessary to make sure they are functioning correctly. We check windows as part of our home inspection service in Olympia, Washington and surrounding areas!

Questions about your window sash or windows or in need of our services?  Comment below!