Add a adjustable door sweep (just float it on the bottom of the door to find the right spot) and remove the threshold. Then shim the threshold up to match the sweep. This will take some tweaking to find the sweet spot where there isn't a gap when closed and yet the door will fully open.
Suggested solution for uneven door threshold issue
We suggest the homeowner lifts the carpet and underlay by installing 9mm Easyshims under both in the doorway. In so doing, this will reduce the floor level difference to 25mm.
If the gap is a fraction of an inch, you can get a door sweep. They come in soft vinyl, heavy felt, or a brush. They will have a metal rib with small holes for small screws. Close the door, and from the inside set the soft side on the threshold and mark it for length. Cut it to length on the hinge end.
Raise the threshold where light enters by turning the nearest screws counterclockwise. Set a straightedge (such as a framing square) on the threshold and adjust the other screws to make sure the adjustable strip is straight. Close the door and check for light. Readjust the threshold until you've eliminated the light.
If the door itself is uneven, you can shim the hinges to adjust it. You can also add shims to a door frame if it's uneven or warped. If you've got a problem with your door sticking, there are a few things you can try to solve the problem.
Effectively Sealing a Gap Underneath an External Threshold
However, if the gaps are larger, a heavy-duty, weatherproof expanding foam is your best option. This foam will expand to fill the whole space, providing a thorough seal against draughts, moisture, and pests.
To adjust the threshold, shims or screws can be employed. Shims, typically made of wood or composite materials, are inserted beneath the threshold to raise or lower it, addressing uneven gaps or misalignment. Alternatively, screws can be loosened or tightened to achieve the desired height.
Sealing a Door Threshold Using Caulking
Use masking tape to cover the edge of the threshold for protection and to ensure clean lines. Using either a caulking gun or tube nozzle (depending on which caulk you are using), slowly apply a consistent bead of caulking along the gap between the threshold and the surface.
Displacement of a threshold reduces the length of runway available for landings. The portion of runway behind a displaced threshold is available for takeoffs in either direction and landings from the opposite direction.
Other tricks of the trade for uneven door thresholds
For example use Easyshims in combination with a Compression Bar. And, if none of the above are sufficient to bridge the gap between your floors, take a look at the Lips and turn it into a proper, neatly trimmed and safe step.
Door sill and threshold both are found at the bottom of the door. The sill is the part of the structure that sits under the jamb. As for the threshold, it is installed on top of the sill and makes the door waterproof and weather tight.
Solution: Misalignment can often be corrected by adjusting the threshold's position. Loosen the screws holding the threshold in place, realign it so that it is level and even, and then retighten the screws.
By using a threshold adjustment layer, we can manipulate the intensity of an image's colors based on a set level. This technique is particularly useful when working with images that need specific adjustments based on brightness levels.
Most interior thresholds can be removed using a hammer and pry bar, targeting the nails. Once you have removed the nails from the threshold, use a hammer to pry the threshold out from under the door stops.
While it is hugely useful, it should not be used to solve all problems. One such example is electrical boxes. Expanding foam shouldn't be used in these locations as it could cause jams that would be expensive to repair. So avoid using it around sockets or light fixtures, or any electrical components in the property.
Most exterior door thresholds also have a sill beneath them. If the threshold is rotted, the sill probably is, too. The sill is beveled on one side to drain water away from the house. It fits tightly between wall studs and under the jambs and casing, so you must cut it before removing it.
Product information
This 750ml expanding foam filler by Gorilla Filler is perfect for weatherproofing and sealing gaps. It expands to fill voids, providing an airtight and waterproof seal.
If the door slab is rubbing against the frame when you open or close the door, then it is not level in the frame. This could be caused either by an improper installation or foundational shifting. If you've experienced this problem since your door was installed, it is most likely an installation issue.