Replacing a threshold is easy. Replacing a threshold and getting a tight fit on both sides is a little trickier.
But it’s not something you should be putting off. A worn threshold compromises the door’s weather seal, and the last thing you want is cold wind whistling through your house. (Or, cool air rushing out on a hot summer’s day.)
Thankfully, hardware stores, home centers and lumberyards have a number of wood thresholds available. And this guide will help you get a nice, snug fit.
Selecting a Threshold
One of the best thresholds to get is a 3/4-inch tall one without a rubber insert. Why? That rubber insert might seem like a good idea, but because you can’t adjust it, you’ll never get a precise fit. The insert can also fill up with mud, snow, and ice, so do yourself a favour and use a sweep instead.
And you can’t just install a jamb cut to the correct length and expect to get a tight fit. You need to create a template, and then transfer the jamb’s contours to the ends of the threshold and make matching cuts.
Creating a Template
Rip 1/4-inch thick hardboard to the same width as the threshold. Now it’s time to trace the template. Butt it against the face of the jamb, where the new threshold will sit. Spread the scribe to make up the widest distance, hold it perpendicular to the jamb, and trace the profile.
You’re now ready to cut your template. Be careful, and don’t try cutting it out perfectly with the first cut. Instead, use a jigsaw to cut the template wider than the line. Then, use a bastard file or saw rasp to fine-tune the fit. (A saw rasp works even faster and produces better results.) Whatever you do, make sure the cuts are square.
Next, measure the opening from the inside of the casing and add 1/16 of an inch for touch-ups at the final fit. Again, be careful as you make your cut.
Creating and Installing the Door Jamb
Now it’s time to transfer the doorjamb profile. Hold the template on the bottom of the threshold, flush to the end. Then, use a sharp pencil to trace the profile onto the threshold, using the same template to mark the other end of the threshold, so everything matches up.
Cut the notches in the threshold with a jigsaw. They’ll be rough and jagged, so you’ll need to clean them up with a rasp. Check the threshold for fit, and as you’re doing it, make a small tick at the edge of the casing. Ease the edge of the threshold with a sanding block, finish it with stain or varnish, and you’re ready to mount it in place.
It’s a good idea to install the threshold with screws, so it can’t work itself out. But, before you screw it down, drill some pilot holes with a 3/8-inch by 1/2-inch deep counterbore. Screw the threshold down by putting one screw in the middle and one about four inches from either end.
Finish them off by gluing matching 3/8-inch plugs into the holes, trimming and finishing them once the glue has cured.
Congratulations! The hard work’s done, and now you can stand back and admire your handiwork.
That wasn’t so bad now, was it?