There is no rocket science involved in measuring for a door replacement. Whether you are measuring an empty door frame or an old door that needs replacing, it is a relatively simple process. All you need is a tape measure and the knowledge of how to use it for accurate measurements. You can measure the door in use, just the door frame, or the entire opening of the door.
To understand the measurements, you will need to have basic knowledge of the door’s construction. It will help you with how to measure the door for replacement.
Basics to Measure Door replacement
There are two types of door replacement options available in the market.
Pre-hung Door Replacement Units
Did you know you have the option to replace not just a door, but the entire door unit? These are called pre-hung doors. A pre-hung unit consists of a door hanging with hinges fitted in a jamb frame. A pre-hung door has two variants.
Interior Pre-hung Doors
These units include top and side jambs without any door threshold, sill, or decorative trims.
Exterior Pre-hung Doors
Exterior pre-hung units come with a four-sided frame and a threshold. Most of them have exterior trims included with them. This exterior trim is a molding made of traditional thick wood, known as “brick mold.” However, you have a choice to use either a brick mold, or you can replace it and use a molding that suits your taste or need.
Door SlabS
If you only want a replacement door, then you have an alternate option to get just that. These replacement doors are called door slabs and come without any hinges and jambs. However, do not confuse the door slab with the slab style door or slab door. The latter are doors with flat or dull sides and do not have decorative contours or panels.
The process of measuring a replacement door is similar in both interior and exterior doors. However, a pre-hung door requires additional measurements. It is critical to ensure the trim fits the opening for the sliding.
Anatomy of a Door
Rough Opening
A rough opening is the structural opening for a door in the wall. Wall studs at the side, top, and sill at the bottom help create this opening.
Jamb Frame
It is commonly known as a door frame made of wood or a door to hang from it. In the case of an interior door, it consists of side jambs, head, or top jamb. In the case of an exterior door, it also comes with a threshold.
Interior door frames traditionally have “stops,” which are narrow strips nailed within the frame to create edges and the door closes against these edges. In exterior doors, jambs have built-in steps to serve as stops.
The door frame usually measures half an inch shorter and half an inch to three-quarter of an inch narrower than the rough opening. This measurement provides you room to fit the door frame into the rough opening and square it up before you can fasten it up. Once the door is in place, you can use decorative trim to cover the gaps between the frame and the finished wall and around the bride and frame. These trims are casting that need to be removed when taking measurements for a pre-hung door. You can leave them on in case you only need a door slab.
How to measure for a Replacement Door
Pre-hung Door
A pre-hung door comes with a fitted door; therefore, its measurement focuses mainly on the frame. The measurement includes the following steps:
- Remove the trim or casing on one side.
- Now you can measure the width of your door frame. Simply use the measuring tape from the jamb on one side to the jamb on the other side of the door frame. To ensure accurate measurements, take three measurements that are from the top, middle, and bottom of the frame. It is safe to use the lowest measurement; otherwise, a large door will not fit the frame.
- Measure the height of the door from the header to the bottom or floor. Again, take measurements in three places and use the smallest figure.
- It is time to measure the jamb’s width from the external to the internal edge. Do not exclude the exterior trim. This width must match the thickness of the wall.
- Now you can measure the trim frame. It is the width and height of the frame on the exterior side of the door.
- Double-check for the door swing before placing an order.
Door Slab
This one is straightforward, as you only have to measure an old door.
- Measure the width of the door in three places and go with the smallest measurement.
- Similarly, measure the height in three places and go with the smallest measurement.
- Lastly, measure the thickness of the door. Measure the area of the jambs between the backside of jambs and the stops. It is the depth for the pocket in which the door will fit if you close it.
Patio Door
- You can draw a sketch on the paper before you begin with the measurement.
- Now take the height and width in three places and use the smallest measurement into account for both.
- Again, if you are only replacing a door panel, then just measure the door. However, if you are replacing the whole frame, then use the rough opening to measure for a perfect fit.
Get Experts to Do It for You
Even when you are good at a DIY, you should get experts to help you with door replacement. It saves your time, hassle, and money. They will provide you the best options available in the market; plus, you do not have to deal with the headache of second-guessing your measurements. Builders & Remodelers has taken pride in providing quality custom doors since 1952. For a door replacement job you can trust, call us today or get a free, no-hassle quote by filling out our online form.
