How to install interior door

This article is about how to install  interior door. Consequently, in this article we show you how to choose the right door to fit your needs and tastes, how to make sure it is level and how to install it using polyurethane foam. As a homeowner you will face a lot of situations when after a remodeling, you have to install a brand new door, as to freshen up the dull appearance of a room. That is why, you could install the door by yourself, as a diy project, to both save a few bucks and to enjoy the result of your own work. Installing an interior door is not a difficult nor a time-consuming project, but you have to learn few basic techniques, as to get the job done in a professional manner.

[dropcap]1.[/dropcap] First of wall, you have to use a tape measurement, in order to know the size of the door you will install. Consequently, make sure the angles of door entrance are right cornered, and that the space between the door frame is even. In addition, it is as important to measure the distance between the door sill up to the top jamb. With these dimensions in mind, it would be easier to find the right door for your tastes and needs. There are a lot of alternatives on the market, from ready to finish up to finished doors, with or without glass or painted in a large variety of colors.

[dropcap]2.[/dropcap] On the other hand, your new door may come in several varieties:  you can order a pre-hung or a slab door. The first option is the best, from our point of view, as it spares you from a great amount of work; in addition, it is pretty difficult to assemble the door jamb and to install the door hinges, especially if you haven’t done it before. Consequently, buy a pre-hung door although it comes at a higher price, as o get rid of a lot of headaches.

[dropcap]3.[/dropcap] There are several ways to fix a door, according to the material of your walls: if you house is made of timber, the most efficient way is ti fix the door using nails, on the other hand, if you live in a house made of bricks or concrete blocks, it would be easier to use polyurethane foam.

[dropcap]4.[/dropcap] If you have to replace an old door, it is a good idea to remove it before installing the new door. Consequently, you should start with removing the door castings and then the door hinges. Nevertheless, you should remember that the door is quite heavy, so it would be wise tho call a friend to assist you while removing the old door and installing the new one. Last but not least, you should remove the door frame and the door sill (if it was part of the old door, otherwise you should replace if it’s in bad condition).


Made from this plan



In order to install an interior door, you need the following:


  • Pre-hung door
  • Polyurethane foam / 3” nails
  • Spacers





  • Make sure the door is level, before fixing it



  • Two hours, two persons



Preparing to install the new door

Measuring the width of the door opening

Measuring the width of the door opening


First of all, you have to make sure the door opening is clean of residues and it is prepared to install the new door. If you want to replace an existing door, then you have to remove it together with the door frame and jamb. This job is pretty difficult for an unexperienced diy-er, so you could either hire a qualified professional or ask a skilled fried to assist you.

After you have removed the old door, you have to use a tape measurement to determine the width of the door opening and the distance between the bottom sill and the header. In this way, you will be able to buy a new door which will fit your door opening.

Smart Tip: Use a L-square to check if the corners of the door opening are at 90º. If you notice they are not right-angled, you could either install spacers or remodel the walls, making them at 90º.



Installing the pre-hung door

Making sure the door jamb is level

Making sure the door jamb is level


If you have bought a pre-hung door, then in most of the cases the hinges are already installed. Nevertheless, if they aren’t, you should use 2” wood screws and an electric screwdriver to fix the door hinges to the jambs.

Next, you should position the frame and the door inside the opening, of course with the help of a fried, as they are quite heavy. Next, move them until you find the perfect fit. Make sure you have left a clearance space between the door and the floor, otherwise your door wont open – you could make sure the space will not decrease during the process by using 2 spacers (1/2 – 1”).

Afterwards, use a spirit level, to check if the door is aligned properly. Use the level on the side jambs, on the head jamb and on the door itself. If the frame is not aligned properly, you have to install door shims to correct the alignment.


Fixing a piece of timber between door jambs

Fixing a piece of timber between door jambs


Install the door shims in the place where the door is not leveled. In order to obtain a perfect result, you should use shims of different dimensions until you notice the frame is aligned properly.

Next, you should use a piece of timber to make sure the polyurethane foam will not push the frame off its position. Consequently measure the distance between the door jambs and cut a piece of timber at that length minus 1/2”. As to protect the door frame from scratches, you should install two pieces of cardboard at both ends of the piece of timber.

Smart Tip: If you want to make sure the polyurethane foam will not move the door from position, you should use at least two pieces of wood, one at the top of the door frame and the other at the bottom of it.


Fixing the door jambs with foam

Fixing the door jambs with foam


After you have locked the door frame into position, you should make one last check. Just close the door to see if the space between the door and the jamb is even from top to the bottom. If the gap is uneven, then you haven’t installed the shims properly, consequently you have to redo the whole process until you notice the alignment is right.

Next, it is time to install the door permanently, using polyurethane foam. Consequently, use the polyurethane foam to fill the space between the walls and the door jambs. Do not use too much foam, as it expands and it could damage the alignment of your door, but if you have followed our previous guidelines it should turn out good.

Smart Tip: As to prevent the door jambs from getting dirty with the polyurethane foam, you have two options: on one hand you can pulverize water on the jams before using the foam spray, or you could mask the door frame with paper tape.


Fixing door into opening

Fixing door into opening


Continue applying the polyurethane foam around the door jambs, making sure you do not move the door from its place, otherwise your hard work would be for nothing. Fill the space between the concrete wall and the door jamb with foam, as to obtain a even layer around the whole perimeter.

Remember that before applying polyurethane foam you have to make sure the door is level and it opens properly. In addition, it has to be aligned with the walls of the room, as to be able to install door trims. This aspect is essential, otherwise you would end up with an unpractical door. Last but not least, the door should be fixed firmly in the door opening, using the shims. If the door is not locked into position, it could slide or even injure someone.

Smart Tip: After applying the foam on one side of the door frame, check if the door is till level.


Installing door

Installing door


After you have finished applying the polyurethane foam around the whole perimeter of the frame, you should close the door, as to make sure the center of gravity is aligned with the door frame. In this way, the door will stay on its position and you won’t face any issue with it, after the foam dries out.

Usually, you have to wait at least one day until the door could be opened and the shims and the two pieces of timber removed. Consequently, do not try to use the door until the polyurethane foam dries out completely. Even if the exterior of the foam looks dried out, we ensure you that it has not dried out completely. Therefore, wait just one day until you can use the door at your will.

Smart Tip: You should remove the excess foam by using a cutter, after a few hours from applying it, as to prevent it from sticking it to the door jambs.



Thank you for reading our article about how to install an interior door, and we recommend you to check out the rest or our projects regarding door and windows.

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