How to bend baseboard around a curved wall
By Nathan Denson/ By the Book Builders
Recently, we completed a kitchen with a round floor plan, and had to figure out how to install baseboard along a curve. There are several ways to bend wood. Most techniques require special tools and significant time. However, there is one technique that, if done properly, can be a quick and simple solution that provides professional results. Any curve over an eight foot radius can to be bent using the following technique.
Typically, baseboard is bent by back-cutting the square stock so that it becomes flexible. The molding (cove or bed, for instance) bends easier and covers the cut marks. One-piece trim can be a bit more tricky, so here are some tips to make it easier.
Begin by choosing the material and pre-sand. Sanding in place with curved trim will result in an uneven finish. Next, use a string to determine your rough length. A tape measure will tend to kink and give an inaccurate measurement. Mark the string where you intend to end your trim, and transfer the measurement onto the stock.
More on Finish Carpentry
Prepare the starting point. Cut a 90 degree end on the baseboard that intersects the curved portion. Using a miter saw and chisel, remove a ¼ inch of the square material, the width of the baseboard thickness, without touching the band profile. This creates a stop to contain the stress of the bent trim, without the use of fasteners. Now cut a 45 degree bevel on the mating end of the bending piece, cutting the band profile only. Cope the profile onto the right side. Now cut the square material so there’s a ¼ inch of material protruding to fit in the opposite side.
Kerf the backside. Lay a scrap of baseboard face down on the miter saw and set your saw depth stop to allow a plunge cut two-thirds into the back of the trim. Now continue the cut, stopping the blade 1/8 inch from the top of the band profile. Be sure the blade doesn’t cut through the face of the profile. A stop block will hold the trim where t you want it, and allows for quick, consistent score cuts without over or undercutting. The relief cuts will allow the trim to flex without damaging the face . Now place your finish piece face down on your saw. Starting at one end, score the back of the trim with 1/8 inch spacing in between cuts. Continue all the way to the other end of the board. I recommend having an out feed bench or a helper to hold the trim as it will become very flexible as you go.
Using the string again, determine the finished length. Lay the string across the board and mark you final cut. After making the cut, you are now ready to install. This may require two people, depending on the radius of the bend. I recommend using screws for fastening as there can be stress on the wood, and screws will ensure a tight long-term hold. You may choose to counter sink and plug the screw holes. Here, we pre-drilled, used finish head screws and used wood filler to fill the holes. Glue the coped end to ensure a long lasting tight joint and fasten at every stud, one at a time only, bending as necessary to hold the wood tight to the wall. Over bending during fastening can fracture the wood, so take your time and feel the stress in the wood. If it feels like there’s too much stress on the wood, let it rest for a few minutes and ease it to the next fastening point until the entire length is fastened. Repeat the entire process for the shoe molding. If you hear cracking, stop and add relief cuts. The key to bending wood is to take your time and listen to the wood. You will only get one try with a piece so be sure to follow each step closely and you will be able to achieve beautiful results.
Cut the notch that anchors the bend.
Ready and in place.
Use string to measure the curve.
Set the depth on the miter saw and back kerf the stock.
Any tension from the bent piece on the left is contained by the notch.
The shoe is kerfed and bent in the same way.
The finshed product, after the screw heads are filled.
...and the finished kitchen.