Quite often installers face the challenge of meeting up to other floor materials that are not on the same level as our wood floors. The standard solution is to have a baby threshold or some sort of T-mold to cover both floor materials, or a reducer that either slopes down to the other floor or, turned around, would ramp down from the higher floor.
Occasionally (and probably more times than we care to count), the materials we run up to are not on the same plane, let alone the same level. That brings new challenges on how to make a decent-looking transition.
For an example, let’s imagine a 36” doorway that has stone on the other side of our wood floors. The stone is 3/8” high on the left side and flush on the right, relative to our wood floor. The transition strip we need is a small saddle, but has to have a sloped underside running from nothing on the right to 3/8” on the left to accommodate the “out of planeness” one floor is to the other, all the while being even on the wood floor side.
There are a few ways to deal with making the mini saddle transition that has an underside tapered rabbet, depending on what tools you have at your disposal.
Everyone has a table saw, so I will start with that tool’s capability to cut a taper.
The table saw fence is parallel to the blade, so any board against it will just be cut to the gap between the two. You can use this as the basis for cutting a taper. First, start by adding an auxiliary fence that has a length two times longer than your tapered rabbet transition needs to be. This fence will guide your workpiece from before the blade all the way through the cut.
Now that you have the auxiliary fence up, set up the max thickness your transition needs to be; for our example, the mini saddle will be 3” wide x 5/8” at maximum thickness and making a rabbet that tapers from 0” to 3/8” in 36”. Set the fence inside blade to 5/8” and run the board through for thickness, usually a double cut for a 3” wide board.
For your 36” piece, add a 3/8” chip of wood to the face at the “0” end the rabbet has to run down to. The chip only needs to be about ¼” wide, but well stuck to the board face. Blue tape and superglue (or hot melt glue) make this easy to stick on and easy to take off when gluing the block to the board face.
Set the blade to half the width of the transition, in this case, 1-1/2” deep for a 3” mini saddle. Make your pass with the glued block side against the fence and the leading edge also against the fence. There will be an open space to the fence between the two ends and you want this to happen; that is what makes the taper happen. The board will now pass through the blade at the angle set by the glued-on block. Use a very large and wide push block and push stick to keep vital body parts away from spinning blades! Safely complete the cut and turn the saw off before removing the push block from the blade.
The first part of the tapered rabbet cut is made. Remove the glued-on block because we are now on to the underside cut. For that, you need to know what the climb rate is for the screw driving the blade up and down in the table saw. Most saws have a climb rate of 1/8” or 3/32” per handle turn. As a side note, you should mark this on the body somewhere for future reference. Set the fence to the 1-1/2” inside measure that is the rabbet (the notch we are making) and set the blade to the depth of the end being cut, either 0” or 3/8” depending on which way you are passing the board through.
The idea is to pass the board through as you raise (or lower) the blade to cut at the notch you are making. Mark your 36” board from the “0” end with 3 marks at 12” intervals: 1/8, 1/4, 3/8, representing the depth of cut the blade needs to make at that point. Since we have a kerf in the wood there is some margin of error we can use so as not to cut up into the body of the baby threshold. Again, use push blocks and push sticks when passing the board through this cut. As you pass the board through, you raise (or lower) the blade from mark to mark as needed without cutting into the underside of the baby threshold.
Now you have the tapered rabbet cut on 1/2 of the transition strip with the other half remaining at full 5/8” thickness. A little belt sanding and hand sanding to round the edges as needed for a pleasant looking transition and the work is done.
Now if you need to make a flat transition (not a lip over type) say, for an elevator’s deep doorway, you can use your planer to do the same thing in both front-to-back and end-to-end directions. All planers have a similar climb per turn characteristic as a table saw blade. Find out what your planer climb rate is (mine is 1/16” per turn) and mark it on your planer.
Say you have to make a wide-angled reducer. First get the lumber to the desired thickness of the fattest part; generally, you are matching the ¾” flooring. For our example, we will be making a gentle-sloped face with a 1/8” front edge. Using blue tape and some fast-setting adhesive of your choice, add to the bottom of the edge to be 1/8”, a strip of wood that is the 1/8” plus another 1/8” so when passing through the planer, a flat zone of 1-2” remains at the thick edge when the front 1/8” thickness is reached. Leaving a 1-2” flat zone on the thick part of the reducer makes for a pleasant-looking transition piece. Back off the planer table a few turns and start passing the lumber through. You will see the reducer face develop as subsequent passes are made. If at any time you think the face will reach the 1-2” flat zone before the leading edge is 1/8”, you can always add a thicker (or thinner if the opposite is true) piece at the thin edge and continue with passes as needed.
You can also make very long tapers that a table saw cannot handle using a planer. I have made 16-foot taper transitions using my planer’s climb rate information.
Let’s say you have a 16-foot opening that has a 1” tall stone floor at one end and at the other end it is 1/2” tall and you want to make a reversed reducer (not a saddle) to accommodate the transition. Get your lumber to 1” thickness overall to start. Then on the side facing your handle, mark equal increments of 1/16” from one end to the other. For a 16-foot board that has to go from 1” to 1/2”, each 1/16” mark is 24 inches apart. This identifies your finished thickness desired at that location on that board.
Note that all planers have a set feed rate and this can be used to time the turning of the handle in sync with your thickness marks. In most cases, you have to change the handle rotation speed to match what the planer can accommodate for max cut depth.
Start with the thickest end first. On the first pass, you can only cut 1/8” max depth so you time the turn handle at a rate of 1 turn for half the board, making 1/8” over the whole 16’. Return the handle back two turns to the original position and repeat, this time turning the handle at twice the previous rate (1 turn per 1/4 the board length) to get to a 1/4” reduction overall. Return the handle to the original position (back 4 turns) and repeat again for a 3/8” overall removal (1 turn per about 2.5 feet). Continue returning the handle and repeat this process once more with a handle turn rate of 1 turn per 2 feet (makes 8 – 1/16” changes per 2 feet for 1/2” drop overall). You now have a board that is 1” at one end and 1/2” thick at the other with a very smooth and gentle slope. Now break out your belt sander and begin to shape the board into a visually pleasant reducer shape, and fit it into the floor.
Now you have the ability to resolve your transition issues. As these techniques are being mastered, you will find many variations along the way that will fit nearly any situation.
Lenny Hall is owner of Endurance Floor Company Inc. in West Park, Florida, and an NWFA Regional Instructor. He can be reached at email@example.com.