Older double hung window sash often rattle and allow cold air in where the two window sash meet. To prevent this from happening, install two window latches on each window, rather than just one, to pull the two sashes firmly together.

Space each window latch about one-third in from the sides of the window frame, or center each latch over a window pane.

Watch the video above to find out more.


Joe Truini: If your home has double-hung windows, you might be familiar with this sound. It’s the sound of an ill-fitting, rattling sash. Now even with the sash lock engaged, you can still sometimes get rattling. And that’s the sound of you wasting money because heated air and cooled air is escaping.

So the solution is to replace the sash lock. Go to the store and get a new sash lock but get two. We are going to replace one sash lock with two. I’ll show you how that works. I did that on this window earlier.

First, I removed the old sash lock—and I’ll come back later and paint this and fill the holes—then I installed the new sash locks to either side about a third of the way in. Or in this case, I centered them on the glass pane on either side.

And now when you engage two locks, you’re locking the sash together in two different places and it’s no rattle at all. And you’re saving money year around.

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avatar for Joe Truini

Joe Truini

Radio Show Co-Host

Joe Truini is a contractor, author, and the host of “Simple Solutions” on Today’s Homeowner TV and the weekly Today’s Homeowner radio show. He has worked on both large commercial projects and residential remodeling, and has written for national publications such as This Old House and Popular Mechanics. He has also written eight books, including three best-selling shed-building books. Joe lives in Connecticut with his family and enjoys hiking, traveling, and baseball in his spare time.

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