Most exterior/interior thresholds are made of quality hardwood, however over time they may deteriorate. Constant use, dry rot, bug infestation, and the effects of changing weather patterns are just a few causes of deterioration. At some point you may have to replace the existing threshold.
Most home improvement centers have pre-cut hardwood thresholds that only have to be trimmed to fit the existing space. There are two general wooden thresholds, flat and capped. The cap portion can be either a metal or also of hardwood, depending on your preference. The flat wooden threshold is replaced the same way only without the cap.
Most exterior/interior thresholds have some type of cap on them, so the first thing to do is to remove the cap portion. Metal caps are easy, they usually have a minimum number of screws holding them to the primary threshold. Hardwood caps usually have nails and/or screws attaching them, this you will have to determine on a case-by-case basis. Assuming the cap is wood, gently slide a pry bar at the seam where it meets the threshold and lever upward; take care not to damage this portion, if it is in good condition it can be reused.
Once the cap is removed you will find that the primary threshold is held in place by either nails or screws or a combination of both. Find how and where the threshold is attached and remove the attaching hardware by the most efficient method, i.e.: screwdriver or some form of nail remover, hammer claw, cat’s-paw, or pry bar.
Being assured that all attaching hardware (screws and nails) have been removed, slip your pry bar beneath the threshold where it meets the wood footing on the foundation and gently loosen upward to break any time-pressure seal. With the old threshold now loose, slide it outward toward the exterior of the doorway, you may need to lever from the back with a pry bar and work the old wood out slowly to lessen any possible collateral damage to the entry. Most homes today are Stucco Coated, so removing the threshold will cause a minimum of damage.
Once the old threshold piece is removed, clean all debris from the entry using a three (3) inch dry paint brush make sure there are no loose wood shavings, dirt or other obstructions. When the existing threshold is removed it will either be straight edged or notched, for easy measurement place the old piece over the new piece bottom to bottom, and mark the cut for length and notch if necessary. Be sure that the back portions (the thicker sides) match up.
After you have made the required cuts with a saw of your choice, sand to a minimal smoothness. Now slide the new threshold into place, you may have to tap it some to flush it to the sub-flooring. Place a piece of scrap wood against the face of the threshold and tap hammer against the scrap piece; this will keep from dimpling the new hardwood.
Now that it is snug in place, pilot drill for fastening, using screws will give you a tighter seal underneath. Countersink the pilot holes to recess the screw head. Then make permanent attachment and cover screw heads with wood putty and sand flush. Replace cap portion setting the edges against the doorstops of the doorframe (casing).
With the new threshold installed you can either stain or leave natural color, but coat with a sanding sealer. Oil-based stains are recommended. After sealer dries, sand lightly with 220 or 320 grit to smooth surface and then coat with a good oil-based fast drying varnish. You may want to use more than one coat of varnish, both for appearance and longevity of the new threshold, sand smooth between coats.
After all the varnish has completely dried (allow a minimum of 24 hours) you can repair any minor damage to the surrounding Stucco. You can buy a pint of pre-mixed stucco compound at any home improvement store. On the new, dry threshold apply two layers of masking tape around the area where the Stucco is to be repaired, this will protect your new threshold, and then apply the pre-mixed stucco compound with a two (2) or three (3) inch wide putty knife pressing the compound well into the space until it builds up even with the existing wall. Allow to dry for the time recommended on the compound container, as this varies with brand of compound, apply an additional coat if necessary. When all Stucco patching is dry, prime and paint to blend with wall.
