How Do I Fix That? Part 3: Installing Blinds

How Do I Install Blinds? – How Do I Fix That? Part 3

While we might enjoy watching the various home improvement shows filling up cable programming, many of us can’t complete the most basic of home improvement projects. The How Do I Fix That? series will show you how to tackle a range of problems that have plagued homeowners for time immemorial. Each installment will provide a walkthrough for the problem at hand so you’ll know what to expect before you get started. Now, get into your old work jeans and roll up your sleeves – we’re going to get messy.

How Do I Install Blinds?

How Do I Fix That? Part 3: Installing Blinds
The finished product. Let’s learn how you get here!

In this installment, we’re going to help you with one of those tasks that somehow feels simple and difficult at the same time – figuring out how to install blinds in your windows. We’ll look at placement for a basic set of blinds, some of the structural factors to keep in mind, and how to measure and install them.

Blind Ambitions

Basic window blinds are available from home improvement centers in a set of standard lengths, or they can be custom cut. Consequently, before you head out the door to buy them, you’ll want to determine how you plan to mount the blinds and measure the windows. The brackets for the window blinds we’re installing can be attached in two ways to the window frame:

  1. Inside Mounting — This is usually mounted inside the window casing between the window sash stops so the blind can be situated well behind the curtains. A sash stop is the wooden piece keeping the window sash in place and allowing it to slide up and down.
  2. Outside Mounting — Located along the top of the window, either directly into the wall above the window casing trim (or moulding) or directly onto the casing trim. This is so, if there aren’t any curtains, the blind completely covers the window. You’ll want to add 3 inches to your measurement so there’s enough overlap to cover the sides.

When you order blinds from a manufacturer, the standard practice is to always give the measurements as width x height. The manufacturer will also reduce the width of your measurement by about 1/2” to ensure adequate room for the blind to fit.

How Do I Fix That? Part 3: Installing Blinds
The first rule of “How Do I Fix That?” – Be sure you have the right tools!

In our case, we’re purchasing some inexpensive stock blinds from a home improvement center. We want to mount them between the window sash stops so it will be out of the way of the curtains.

Measuring between the sash stops shows our window is 33” wide. Because finished blind sizes can vary as much as 1/8”, all manufactures recommend you round down to the nearest 1/8 inch. That leaves us with 32 7/8”. Factor in reducing this by 1/2” and we’ve got a minimum size of 32 3/8”. However, there’s still enough room to go a little higher to 32 1/2”.

Meanwhile, the height from the window sill to the top sash stop was 52 1/2”.


We bought some inexpensive stock blinds “sized” for a 33” window. However, the actual measurement was 32 1/2” wide — which is fine because we still have plenty of clearance.

Because our blinds raise and lower with a pair of drawstrings, we’re going to mount brackets so that the screws be embedded firmly in the window’s wooden frame. This way, repeated tugging on the drawstrings won’t slowly pull down the mounting brackets, and the blinds clear off the window.

How Do I Fix That? Part 3: Installing Blinds
Also, when you buy a window blind kit from the store, make sure it contains everything you’re supposed to have. You can’t be short a screw or bracket.

Our kit contains two plastic brackets for the ends and one metal bracket to provide support in the middle. While we could technically skip using the metal bracket, mounting it can prevent the blind’s head rail (the part with pulley mechanism, etc.) from eventually sagging and breaking. Once this bracket is in place, it will be covered over by the head rail.

The two plastic brackets are pre-molded with several screw holes so we can mount them almost anyway we need to. The big holes let our screw driver get through to tighten the screws, as we’ll see. The plastic brackets each come with a small panel that slides into place to keep the blind’s head rail in place.

To measure the brackets position, we divide the 1/2” clearance space by 2. This gives a measurement of 1/4” of space at either end of the blind. We make our first mark there and then use one of the brackets to make marks through the holes for screws. Because these blinds will take a lot of sun, adding just a few hair-widths of extra space towards the side of the window allows for some expansion.

To find the center bracket’s position, we take 32 1/2” and divide by 2. That’s 16 1/4”. Measure in from either bracket’s mark to 16 1/4” and mark for the center bracket.

Mounting the Hardware

How Do I Fix That? Part 3: Installing Blinds
We sincerely hope you measured at least twice before you start drilling the holes into the window frame.

These screws are about 1/8” diameter. But because we want their threads to bite into the window frame’s wood, we’ll use the slightly smaller 5/64” drill bit. Since both are roughly the same threaded length, it’s not hard to see how deep the holes will need to be.

How Do I Fix That? Part 3: Installing Blinds
Let’s be real – if the manufacturer of the blinds provided a center bracket, go ahead and install it just to be safe.

Once the holes are drilled, it’s an easy matter of putting in the screws. Be sure not to over-tighten them since you could crack the plastic brackets. Once they’re all in, test fit the head rail piece.

TIP: Leave the center bracket screws just a little loose when you first test-fit the blind’s head rail. When you’re happy with the fit, go ahead and tighten these until snug.

Once the head rail piece is snuggly in place, slide the plastic retaining tabs in place at either end. Now test to make sure the blind lowers and raises smoothly without any snags. The head rail is allowed to shift a little in the brackets, but it shouldn’t slide from side to side. Make sure that the middle support bracket is providing firm support as well.

Our kit came with a little valance. This is an extra slat that fits into some clear clips to give the whole thing a more streamlined appearance.

Blinded by Delight

How Do I Fix That? Part 3: Installing Blinds
Ta Da! Doesn’t that look lovely?!

And that’s it! Here’s our blind fitted into place. Add your choice of curtains to complete the look.

And for a bit of energy efficiency, installing blinds can also help keep the room much cooler in the summer months. Keeping them closed during the daytime keeps out much of Texas sunshine and heat that can cause your electricity usage to spike.

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Vernon Trollinger is a writer with a background in home improvement, electronics, fiction writing, and archaeology. He now writes about green energy technology, home energy efficiency, the natural gas industry, and the electrical grid.