When installing flooring, you will often need to add a T-molding or some other appropriate trim to make the transition between two rooms. T-moldings provide the floor with an expansion gap and it gives you a professional edging where it meets another type of flooring. They're available in different materials such as wood, aluminum, plastic, and vinyl and in lengths varying between 36-inch and just short of 8-feet. So in order to use a T-molding, you will likely have to cut it to the right length to fit exactly between door jambs or two walls. Here are the basics of how to cut the molding to the right length.
Measure the Opening
The first thing that you need to do is determine how long of a piece you need. Take a measuring tape and get the width of the doorway or the length needed to reach between two walls where the t-molding will be placed. Measure it as carefully as possible so that you can make an accurate cut without any gaps at either end.
Make the Cut
You can then mark the measurement on the molding. Make sure that you have a fine-tooth crosscut blade on your miter saw and not a ripping blade as it would most likely tear the molding. If a blade needs to be installed, unplug the saw from the wall first, then remove the blade and replace it with the appropriate one.
You can plug the saw back in, and before anything else, put on some eyewear protection such as safety glasses. Place the T-molding securely on the saw's table and against the fence, making sure it sits tightly without any rocking movement. Hold it firmly in place with your hand away from the cutting area, squeeze the trigger to turn on the saw, and firmly but slowly lower the blade onto the molding for a smooth and straight cut, ready to fit. For T-molding that comes with a channel-type holding bracket, the channel can then be cut, slightly shorter, in the same manner as the molding.
If you don't have a miter saw, the cut can just as easily be made using a backsaw with a miter box or by using a hack saw.
Install the T-molding
The molding can now be positioned and secured in place with finishing nails, with countersunk flat-head screws, or by clipping it onto the channel bracket supplied and securely screwed into position.