Normally, the finished floor beneath an exterior door is slightly below the top of the threshold. Your door was trimmed after the new flooring was installed so that it could open, creating the gap you mentioned. The fix involves adding a new ¾-inch-thick oak threshold on top of the old one (to cover the exposed edge of the new flooring), trimming the door slightly, and installing a new door sweep that will make a tight seal when the door is closed while clearing the rug. EXPERT TIP: Use a nailset’s tapered metal end to protect the wood from the final blows of a hammer. Its hardened, cupped tip keeps it from skidding off the nail’s head. The tips come in different sizes: Choose one slightly smaller than the head you want to tap down.

Steps for Retrofitting a Threshold

Resources

To bridge the awkward gap between the original threshold and the new flooring, Nathan cut to size a piece of ¾” oak stock lumber, which can be found at any home center.

How to Install a New Threshold

To cut the board to size, Nathan used a combination of saws, including a TS 55 circular track saw, which is manufactured by Festool and a sliding compound miter saw, which is manufactured by Dewalt. Nathan secured the threshold to the floor using Gorilla Glue construction adhesive and brad nails. To help the new threshold blend in with the oak flooring, Nathan applied a polyurethane finish. While most finishes will do the trick, Nathan decided to use a Varathane Clear Semi-Gloss Polyurethane Spray, which is manufactured by Rust-Oleum. The weatherstripping Nathan used was KC500 1-¼” x 84” Gray Triangular Gasket and Aluminum Screw On Door Weather Strip, which is manufactured by Simply Conserve.

Shopping list

Safety glasses Ear protection N-95 mask Desired type of lumber Wood sealant Painter’s tape Construction adhesive Polyurethane adhesive Doorstop Weatherstripping

Tools

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