How to Mount an Aluminum Door Threshold

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A door threshold is a very important part that must be installed properly to protect the door from wearing out and to ensure that the outside rain, slush, cold, or even insects do not intrude inside your home. Aluminum thresholds are easy to mount, more durable, and also good to look at. They are also resistant to dust and moisture. With an aluminum threshold, you save on varnishing and painting expenditure. They are readily available in any furnishing or hardware store, and installing them can be a cakewalk. A few simple steps are all that need to be followed to mount the threshold without any professional aid. This takes only about an hour and cuts down on your expenses too.

Step 1: Taking Measurements

Wear light clothes and safety goggles before starting work. Use a measuring tape and note the width and length of the area under the door where the threshold is supposed to be mounted. Purchase an aluminum threshold of the same measure. You might have to remove the older threshold, which is an easy job if made of aluminum, as the screws just need to be removed for the strip to come off. However, if you happen to have a wooden threshold, you must remove it in the following manner: remove the caulk layer from the older threshold by scrapping it off with a knife carefully. Now, use a pry bar to pry up the threshold by inserting the bar under the wood and push it up. Gradually, the wood fasteners will loosen, and the threshold will come off easily. Clean the ground of the chips or debris before proceeding further.

Setting up the Aluminum Threshold

Place the new threshold in the proper place, to see if it is of the right size. If it is not, shave off the extra inches using the hacksaw. File the sharp edges for a smooth look. Now, place it over the caulked surface using a mallet so that it fits snugly. It must sit straight and firm. This can be ascertained by seeing if the door’s bottom, on being closed, is in the same line as the threshold. Remove the threshold.


Buy silicon-based caulk from a hardware store and apply it neatly along the area that will form the surface underneath the threshold. It must be applied so that it spreads evenly. This is necessary, as caulk is an effective sealant. In absence of a sealant, moisture can seep under the metal, into the house.

Final Steps

Since holes are pre-drilled in the required positions on such aluminum thresholds, all you need to do is drive in the deck screws, and tighten them up using a screwdriver. Purchase adhesive-backed weather stripping from your local hardware store. Make sure that you measure the threshold length and width before purchasing this. Clean the threshold using a wet piece of cloth and let it dry completely.

Take the weather stripping and using adhesive, attach it over the sides and upper surface of the threshold. Check if the door can move and swing easily without the threshold obstructing it. If any defects are seen, you need to remove the threshold and re-mount it all over again. Finally, step back and see for yourself the perfect threshold that you mounted without much trouble.