You’d think my main reason for installing a mouse door in the baseboard was to add a bit of whimsy to our family room addition. You might be partially right, but my real motivation starts with trying to lay baseboard in my kitchen. A few years ago, when I put down the baseboard in my kitchen, I tried to join two pieces with a scarf joint. Because the floor wasn’t completely even and the wall wasn’t completely flat, I spent about about three hours trying to make the baseboards meet in a respectable looking joint, but just couldn’t.
At the time I knew there were other options like gluing the two baseboards together before installing them or running a level line on the wall and scribing the bottom of the base where it met the floor, but I stubbornly refused to step back and try another solution. So I was stuck with a crappy joint.
Back to the present, where in the family room I have two places where I need to join baseboards to span the walls. For one wall, I figured I would make it easier on myself and use something that would hide the unevenness of the floor and allow me to use a simple butt joint. I started to think of things that allow you to use butt joints for trim, like plinth and corner blocks, but I didn’t think having a random plinth block in the middle of the wall would look very professional. Then I thought about baseboards I’ve seen on TV and it hit me: the iconic mouse hole.
I did an image search and found several different styles I liked here, here, and here. Then I asked my daughter to help me choose and build the one she liked. She choose an arched door with the arched frame. So we found a piece of wood around the same thickness as the baseboard and searched for some circles in my shop to use as arch templates. After finding a jar lid and hole saw that gave us the right look, I drew the arch and door on the piece of oak and cut it out on the scroll saw.
A little touch up with some sandpaper and the door was ready to paint. My daughter coated both the door and frame with some brown acrylic paint. To represent empty space behind the door, we cut a shape out of black craft paper slightly larger than the door to slip behind the arch. Then to make the door look like it was made from several planks, my daughter used a sharpie and straight-edge to draw some vertical lines.
I had started to drive the brass nails in for the door hinges, but found that the oak was just too hard, so I had to drill pilot holes with a tiny bit that wouldn’t fit in my cordless drill. The brass nails were still hard to start and drive straight, but with a little patience, I was able to drive them all.
Sure enough when I installed one of the pieces of base board, I found the floor to be so uneven that the straight cut I had made to butt up to one side of the mouse door wasn’t square. Since I had already nailed the piece in place, I had to file the edge of the base so it was square with the door. I had a little more luck with the second piece of baseboard, partially because it was shorter, and partially because the mouse door was so forgiving. You can see in the top picture though that if you connect the two baseboards, they wouldn’t line up, but with the mouse door in the middle you don’t really notice.