How to Install Baseboard Trim

Learn how to install baseboard trim with this simple tutorial.

How to Install Baseboard Trim

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There are a variety of ways to install baseboards, depending on the type of trim you use. I used flat 1×4 MDF for all our trim, so the following tutorial shows you how to install baseboards without coping. If you’re installing 1×4 trim (rough lumber, cedar, primed mdf, pine – any kind of straight board), you’re in the right place!

For fancier trim – the kind with elaborate profiles – you’ll want to cope the inside corners for a perfect fit. See this article for how to properly cope inside corners.

1×4 (or any size flat board) trim is popular for rustic homes. I painted ours white, but it’s still more rustic than elaborate-profile trim. It just depends on your style.

If you’re re-doing trim, start by removing your old baseboards. Once they’re out, it’s time to install the new stuff.

TOOLS & SUPPLIES:

Measure and Cut

Step 1.

Measure the length of the wall. For longer walls, you may have to use multiple pieces of trim and splice them together. Find a stud where you can end the first piece of trim and begin a new one. You want to place the joint on a stud so both ends have a good spot to nail into.

Once you have your wall lengths, measure out the baseboard.

How to Install Baseboard Trim

I measure along the back of the board for simplicity’s sake. The back of the board rests against the wall, which is where you take the measurements. If you measure along the front of the board, you have to adjust measurements at the corners depending on how thick the trim is. I just skip that fiasco and measure along the back to avoid making mistakes.

How to Install Baseboard Trim

Cut inside corners at a 45 degree miter.

How to Install Baseboard Trim inside corner
Inside Left Corner
How to Install Baseboard Trim inside corner
Inside Right Corner
How to Install Baseboard Trim inside corner
Baseboard Inside Corner

Cut outside corners at a 45 degree miter.

How to Install Baseboard Trim outside corner
Outside Left Corner
How to Install Baseboard Trim outside corner
Outside Right Corner
How to Install Baseboard Trim outside corner
Baseboard Outside Corner

To splice boards on a long wall, cut the ends of the spliced boards at corresponding 45 degree miters.

Again, place splices on a stud along the length of the wall so there’s a solid stud to nail the trim into.

How to Install Baseboard Trim splice
Baseboard Splice

Mark the length of the boards as you cut to avoid mixing them up. Mark on the back of the board so you can’t see it once it’s installed.

How to Install Baseboard Trim

As you work your way around the room, dry-fit the boards to make sure the joints are tight. Make adjustments as necessary until all the boards fit snugly.

You can either finish the boards before or after you install them. In new construction, it’s common to install all the trim and then paint or stain it. Since I’ve been remodeling existing rooms, I prefer to paint the boards in the garage and then install it so I don’t have to worry about taping off the floor and walls.

How to Install Baseboard Trim

If you decide to paint (or stain) before installation, make sure to put all the trim in the room to make sure it fits first (do a dry-fit). You don’t want to have to adjust lengths after it’s all painted.

Install

Step 2.

Put the new baseboard in place and find the studs along the wall.

I use a very basic stud finder from Menards, but I’ve heard great things about this one as a more professional option. Or you can pick one up at any home improvement store.

How to Install Baseboard Trim

Once you know where the studs are, press the baseboard into place and nail into the studs with 2″ finish nails.

Make sure the corners are tight and press the baseboard into the ground as you work your way along the wall. You want the baseboard to be level and pretty snug against the floor.

How to Install Baseboard Trim

**Side Note – I cannot recommend my brad nailer enough. I’ve used it on every. single. new piece of trim in our house, and it’s amazing – drives 18 gauge brad nails (perfect for trim), lights up where you’re nailing, and is cordless for easy maneuverability. All in all, a great tool for the every day home improver. I use it on almost every project.

Back to the tutorial …

Work all the way around the room until all the new baseboards are attached.

If you’re using bare or stained wood, you’re done! Finish nails don’t usually show up against wood, so there’s no need to fill the holes. However, if you can see the nails and don’t like it, continue through the next few steps.

Step 3.

For painted baseboards – fill all the nail holes and joints with wood filler. Let the wood filler dry.

While the wood filler dries, run a bead of caulk along the seam between the new baseboard and the wall. It’s easy to see the gap between painted baseboards and the wall, so the caulk hides that joint.

How to Install Baseboard Trim
Baseboard before caulk

Again – typically not as necessary with wood trim since the wood already contrasts the wall quite a bit (but it’s completely up to you if you want to do it).

Make sure to use paintable caulk so you can touch-up the paint … don’t ask me how I know …

Once the caulk and wood filler dry, touch-up the paint.

How to Install Baseboard Trim splice
Baseboard Trim Splice Joint

Remember when I said you can either paint the trim before or after installation – this is why people wait to paint trim until it’s installed. You have to go through and paint the nail holes and splices anyways, so a lot of contractors just do it all at the same time. It’s completely up to you. This is just how I do it … maybe it’s because I’m a little clumsy, but painting right up next to the brand new carpet makes me quite nervous.

Regardless, you end up with the same thing – new baseboard trim!

When it’s all said and done, this is what it looks like on an outside corner:

How to Install Baseboard Trim outside corner
Baseboard Trim Outside Corner

And an inside corner:

How to Install Baseboard Trim inside corner
Baseboard Trim Inside Corner

See how nicely that wood filler and caulk works? It covers the joints really well.

Last but not least, I just cut straight 90 degree ends to butt up against the door trim. This isn’t my best joint, but you can see really clearly how it goes together:

How to Install Baseboard Trim butted
Baseboard Trim Against Door Trim

Aaand there you have it!

I’ve re-done the trim in our kitchen, living room, son’s room, and daughter’s nursery. There are still a few rooms to do in the house, but I’ve used this same method for everything so far and plan to finish it out the same way – it’s simple and looks nice.

Here it is in my son’s room:

how to restore wood windows

And my daughter’s:

girl nursery ideas

Please let me know if you have any questions and I’ll get back to you as soon as possible.

Bitterroot DIY

Thanks for stopping by!

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How to Install Baseboard Trim

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