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How to Build a Custom Wood Window Valance with Moulding

Give your windows an upscale look with a custom wood window valance made featuring Woodgrain’s millwork and mouldings.

Disclaimer: This post is brought to you by Woodgrain. Thanks for supporting the brands that support this blog!

I’ve lived in my current home for almost fifteen years.

Over those years, I’ve spent a lot of time in my laundry room!

Like, a lot of time.

A family of five can generate so many dirty clothes!

Especially when the kids play sports.

But I’m getting off track.

Because the point I was wanting to make is that even though I spent tons of time in this room, I never really took the time to make it a space I want to spend time in!

Laundry room with white cabinets with opening above holding cleaning supplies

This year that’s all changing.

My laundry room is getting a makeover!

Go check out the inspiration board I created to plan how the space would look.

I’m going all French country.

AnnMarie’s redoing her laundry room this year too and she’s going all modern industrial farmhouse.

It’s almost like a competition!

Except we aren’t competing.

We’re actually helping to keep each other motivated to finish our rooms!

One of the first projects I’m tackling is giving my window a little pizzazz.

After all, it’s one of the first things you see when you look in the room.

I didn’t want to do curtains, or any fabric kind of window treatment because of the dust in this room.

Instead?

I’m building a custom wood window valance over the window and making it look pretty with some fantastic mouldings from Woodgrain!

Okay.

My husband is building it.

But I designed it!

And I’ll be doing all the wood putty, and sanding, and priming, and painting, so that basically makes me a DIY queen.

Let’s take a look at how easy it is to give your windows a glow up by building a custom window valance!

Custom wood valance on a window painted Revere Pewter with crown molding and decorative trim

Nice, right?!

Projects in My French Country Laundry Room

It All Starts With Woodgrain

I absolutely love the quality of the millwork and mouldings from Woodgrain!

All of their wood comes from managed forests to ensure sustainable and ethically harvested woods.

Cool fact: Woodgrain uses 99% of every log, all the way down to the sawdust that gets packaged for animal bedding or made into wood pellets!

They offer their millwork in a variety of woods as well as primed MDF options, in a huge variety of styles, so you’ll be able to find exactly what you’re looking for for your next project.

You can see all the types of moulding they offer here.

Woodgrain has dealers all over the world! You can find the dealer closest to where you live here.

What You’ll Need to Build a Custom Window Valance Like Mine

Scroll to the bottom of the post for shoppable links for all tools used.

These are the tools you’ll need to build a wood valance:

  • miter saw
  • table saw or circular saw (optional, see instructions for alternative)
  • stud finder
  • carpenter square or ruler
  • level
  • nail gun
  • impact driver
  • orbital sander (nice, but not required)
  • putty knife
  • caulk gun
  • 2″ angled paint brush

These are the supplies you’ll need to build a wood valance:

  • 3/4-inch plywood
  • crown moulding (I used Woodgrain #45 in primed MDF)
  • base cap moulding (I used Woodgrain #163 in primed finger joint)
  • mull moulding (I used Woodgrain #988 in solid pine)
  • nails for nail gun
  • 2-inch wood screws
  • wood putty/filler
  • paintable caulk
  • primer
  • paint

How to Construct a Wood Window Valance

Measure your window

I’m not giving dimensions in these instructions because there are so many different sizes of windows.

Plus, you might wanna customize the height of your valance to suit your preferences and your home’s style!

Man standing on a ladder measuring space above a window with a tape measure

We used a removable shelf from our laundry room cabinets (that also got a glow up) to visualize the height we wanted for the valance.

Our window has a privacy shade that I wanted the wood valance to cover.

You’ll need to decide how tall your valance will be and also how far you want it to extend past the sides of your window.

I wanted the valance to be close to the same width as the window, and to reach almost to the ceiling.

You also need to figure out how far out you want the valance to extend from the wall.

I wanted our valance to be no more than two inches from the wall.

Cut the wood

We chose to use 3/4-inch plywood to construct the valance.

If you don’t have a table saw or circular saw, many large hardware stores can cut your wood to size!

You’ll need five pieces from the plywood:

  • one large piece that is the front part of the valance
  • two smaller pieces that will be the sides of the valance
  • one narrow piece that will be attached to the top of the valance
  • one piece to be a ledger board that should be the same width as your window
Man cutting 3/4-inch plywood with a table saw outside

Build the valance

After you have the wood cut to build the valance, it’s time to start assembling the box.

Man attaching side edges to a piece of wood

We attached the side pieces onto the main board so that the rough edge wouldn’t be visible on the front (see image below).

Table saw sitting outside with a piece of wood sitting on top and smaller wood clamped to the edge with large adjustable C clamps

We used locking C clamps to hold the piece in place to make it super easy (and safer) to nail together.

Man outside attaching the side edges of a wood window valance with a nail gun

All you have to do is flip it upside down and use your nail gun to attach the side piece.

Repeat this process to attach the other side piece.

Man's hand holding a bottle of wood glue and applying glue to edge of a wood box

Now attach the top of the box.

Start with some wood glue, then nail along the upper edge with your nail gun.

Ta da!

You’ve built the actual valance!

Wasn’t that easy?

Now, let’s make it look pretty with some gorgeous Woodgrain millwork.

Cut the crown moulding

There are some tricks to cutting crown moulding the right way.

You need to plan your cuts carefully, otherwise you can end up wasting a lot of the trim.

You actually put the moulding into the miter box or on the compound saw base upside down!

I’ve created the graphic below with guidance from my husband to help you plan your cuts.

For this project, you’ll be making cuts for outside corners.

Graphic showing how to cut crown moulding

If you look at the picture below, you can see how it looks to put the crown moulding into the saw upside down.

Basically, the surface of the saw is like the ceiling, and the side of the saw is like the wall.

Or in the case of this project, the surface of the saw is like the top of the valance, and the side of the saw is like the valance itself.

Man cutting crown molding outside with a compound miter saw

For this project, when you make the first cut, ideally cut off about 6 inches of moulding from the end.

You’ll be able to use this piece as one of the side pieces of moulding on your valance.

After you cut the first side, you’ll need to change the direction of the miter cut.

To figure out where to make the cut, first measure the length of the valance.

Even if you already know the length, it’s always a good idea to measure it again!

Man measuring a piece of plywood on a table saw outside

Now take this measurement and mark the bottom of the crown moulding for that length.

When I say bottom, I mean the part of the crown moulding that will be attached to the valance.

Man cutting crown molding outside with a compound miter saw

Here’s how the moulding will look after you’ve made both cuts.

See how the bottom edge is shorter than the top edge?

Man outside holding a piece of crown molding with mitered cuts on both ends

Attach the crown moulding

Now it’s time to attach the crown moulding to your wood window valance.

First, decide where on the valance you want the moulding to sit.

Man checking the height of crown molding on a wood window valance that's lying on the ground

I preferred the way it looked sitting down a little lower on the box, not along the very top edge.

Man using a small square to measure location to attach crown molding on a wood valance

Use a carpenter’s square or ruler to mark the bottom edge of the moulding on both sides of the valance.

Man's hands attaching crown moulding to a piece of wood with a pneumatic nail gun

Then line up the bottom of the crown moulding on the marks.

Use your nail gun to attach one edge, and then the other.

Doublecheck that the moulding is level, and then nail 3-5 more spots to secure the moulding to the valance.

You’ll be able to use the last mitered cut you made for one of the side pieces of crown moulding.

Man holding crown molding miter cuts together on a piece of wood

Simply line up that piece of moulding and mark where to cut.

This will be a straight cut, not an angled cut.

It isn’t necessary to position the moulding on the saw the way you do for the angled cuts.

Man cutting crown molding outside with a compound miter saw

Put wood glue along the edge of the crown moulding.

man's hands holding bottle of wood glue and applying glue to crown molding

Then use your nail gun to attach the bottom of the moulding on the box.

Man's hands using a nail gun to attach crown molding on a custom window valance

You can do this with the box lying flat on the ground, but it’s so much easier to do the nailing with the box on its side.

To protected the crown moulding’s corners that extend beyond the valance, simply sit the valance on a block of wood!

Unpainted wood window valance sitting on a 4x4 block of wood to keep crown molding off the ground

You’ll need to repeat the process for the other side of the crown moulding.

Add moulding below the crown moulding

No matter what size you decide to make your valance, it looks pretty to add another piece of moulding a few inches below the crown moulding.

This is often referred to as “crown and neck” moulding.

I chose to use one of Woodgrain’s base cap mouldings for the “neck.”

Mark on the valance where you want to add the next piece.

Typically “neck” moulding is three to four inches below the bottom of the crown.

Man using a small square to measure where to install trim

Use a carpenter’s square or ruler to mark where you’ll be attaching the next piece of moulding on both sides of the wood valance.

You’ll be making regular 45 degree mitered cuts for this moulding.

Custom wood window valance sitting on the floor while being constructed

To attach the neck, add wood glue to the back of the moulding to prevent any gapping, then use your nail gun to nail along the bottom edge.

We’re adding a third row of moulding to the bottom of this valance, but I wanted to see how it looked in my laundry room before deciding where to attach it.

I wasn’t sure whether I wanted that last piece to run along the bottom edge, or if I wanted it to be an inch or so higher.

Install the Wood Window Valance

We recommend using a ledger board to hang your custom wood window valance.

This provides a really secure installation and it’s so easy to do!

First, use a stud finder to locate the studs in the wall above your window.

Man on a ladder in front of a window with a stud finder

Mark the location of the studs on the wall.

The top edge of the box will be attached to the ledger board.

Double check where you want your valance to hang, and mark the top edge of the box (not the top edge of the moulding) on the wall.

Since you’ve used 3/4-inch plywood, your ledger board will go 3/4 of an inch below the mark you made for the top edge of the valance.

The final piece of plywood you cut in the first step will be the ledger board.

Use an impact driver to screw the board above the window.

Tip: Start with just one screw in the center. Then use a level to make sure the board is level. You’ll be able to adjust the board easily with just the center screw.

Once it’s level, add more screws to firmly secure the board.

Man on a ladder in front of a window with a ledger board attached a foot above the top of the window with a level on top of the ledger board

The top of the valance box has been attached with wood glue and nails, but for even more security, use your impact driver to add two wood screws along each side of the box.

Man using impact driver to attach top to custom window valance frame

To hang the valance, simply place the box on the ledger board, and then use your impact driver to add screws along the top edge.

overhead view of window valance box showing how the valance is attached.

This view isn’t pretty, but none of this shows!

If you want, you could add a ledge on top to cover the inside of the box, but we opted to keep it open.

Unpainted wood window valance with crown molding installed on a window with a ladder in front of the window

Now that the valance is hung, it was easier to decide on the best place for the bottom piece of moulding.

Add bottom moulding

We slid the piece of Woodgrain mull moulding up and down along the bottom part of the box.

I decided I liked the way it looked about an inch from the bottom.

Close up of the left side of an unpainted custom wood valance on a window with crown molding and decorative trim

You’ll be making basic 45-degree miter cuts for this piece of trim.

We attached it with wood glue and used nails just at the very edge of the box.

If we’d used nails in the center of the box, they would poke through the plywood and possibly cut our hands when we pull down the privacy shade.

Laundry room during a makeover with an unpainted wood window valance installed on the window. Clamps are holding molding in place on the bottom of the valance.

We used adjustable locking clamps on the middle of the moulding overnight to help eliminate any gaps.

Fill nail holes, sand the wood, caulk, and prime

This is where I come in on the work!

We have a symbiotic DIY relationship at my house: I come up with projects, my husband builds the things, then I do all the finish work.

We’re a pretty good team!

These are the tools I used for the finish work on this wood valance.

You could definitely do this part before hanging the valance, but since we added the last piece of trim after hanging it, I waited until this point.

I decided to apply the first coat of primer before filling all the holes.

I think it’s easier to see the imperfections on a painted surface, and I knew I would need to do two coats of primer.

Use wood filler and a putty knife to fill all the little nail holes and any uneven spots.

Can of Zinsser Bulls Eye primer, container of wood filler, sanding block, and putty knife

Then it’s time to sand everything smooth.

If you have an orbital sander, you could use that on the larger parts of the valance, but I just used a sanding block.

I start with 80 grit sandpaper, then 120 grit, and finish with 220 grit to get it super smooth.

Window topped with a custom wood window valance that is primed with a ladder in front of it

Use a shop vac to remove any sawdust from the surface, and then give it a final wipe with a tack cloth.

Paint on another coat of primer.

I prefer doing two coats of primer and then only having to do one coat of the more expensive paint!

Paint, paint, paint!

Notice anything different?

I also painted the walls and trim!

I wasn’t sure what color I wanted to paint the valance: Super White like the drying rack? Revere Pewter like the window frame? or Lafayette Green like the cabinets?

Window topped with a custom wood window valance that is primed  with trim painted a different color

After seeing how it looked with the walls and trim painted, I decided to paint it the same color as the trim.

I used a satin sheen for the trim and the valance.

Custom wood valance on a window painted Revere Pewter with crown molding and decorative trim

Now you can just sit back and enjoy the way your new custom wood window valance makes your room look!

What do you think?

Close up of the left side of a custom wood valance on a window painted Revere Pewter with crown molding and decorative trim

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