A rough opening is a space cut in a wall where a door will eventually be installed. It supports the door by securing the rest of the wall around it. You might be wondering what the rough opening for your 32-inch-door would be. To answer your question, we consulted experts, and here's what they had to say.
The rough opening of a 32-inch (32 x 80 inches) prehung door is 34 inches wide by 82 1/2 inches tall. These dimensions are enough for the opening to adjust the door and frame.
Continue reading to learn about how to get the rough opening of a door. There's also information on how to frame the rough opening, standard door dimensions, and more.
How Do You Measure Rough Opening?
A rough opening is a door's framed opening. The distance between the rough opening and the actual door size varies. The rough opening must be larger than the door and jambs.
You'll save time and stress while installing your doors if you get the rough opening size right the first time. It's pretty easy to frame rough opening sizes. Simply increase the width of the actual door by 2 inches. This leaves 3/4 inch on each side of the jamb board and 1/2 inch adjustability room for a total of 2 inches.
The height of the real door should be increased by 2 1/2 inches. This will allow you to raise the door frame above the sub-floor. This leaves 3/4 inch for the jamb, 1 1/4 inches for flooring, plus 1/2 inch for leveling.
What Rough Opening For A 32 Door?
As mentioned above, if the door’s width measures 32 inches, just add 2 inches. The rough opening would then be 34 inches wide. For the door height, 78 inches and 80 inches are the standard measurements, but customized sizes can also be obtained. Assuming the door height is 80 inches, if you add 2 1/2 inches, the rough opening would be 82 1/2 inches.
You'll need to consult an architect or engineer to determine the precise measurements required by your local building code.
What's behind the door will determine the size of your rough opening. If you can see all the way through the wall, take a measurement from the middle of it to the top of your header board or ceiling joist.
Otherwise, you'll need to account for wall coverings and any other obstacles. If there are corners or angles, measure along the longest route possible to avoid putting excess material in your project.
Why Is It Necessary For The Opening To Be Larger Than the Door And Its Frame?
The rough opening is bigger than the door and its frame in order to have sufficient space in the opening to adjust the door and frame. Rough framing is referred to as wall framing. Not every rough opening is square and plumb. You can plumb, level, and square your door installation precisely by leaving this extra space.
Additionally, not all doors are the same size. Door sizes differ depending on the manufacturer. Normally, this isn't a big deal, but if your rough opening was small, or the door and jamb were the same sizes, you might not be able to get the door to work correctly without some adjustment.
Keep in mind that the wall should be able to expand and contract as needed. Yes, as the seasons change, your wall grows and shrinks. When it's humid outside, it absorbs moisture, and it shrinks when temperature and humidity levels drop.
Again, we're talking about small amounts, sometimes less than a half-inch, but even this can cause that once perfectly fitting door to stick, rub against the frame, or not latch properly.
What Are The Standard Door Sizes?
Standard heights, widths, and thicknesses for interior doors are as follows:
Height
Interior doors are typically 80 inches tall. This is the most common height for hallway doors that connect two rooms. Because it is 6 feet 8 inches tall, an 80-inch door is called a 6/8 door. A slightly shorter 78-inch door is also available. It's known as a 6/6 door, and it's used for closet and utility doors.
Width
The standard internal door width is 32 inches. A passage door must be at least this wide. A few narrower doors, such as 30 inches, 28 inches, and 24 inches, may also be available. These narrower widths are acceptable as closets and utility doors.
Doors that are 36 inches wide may be available. These more expansive choices comply with the Americans with Disabilities Act (ADA) and are a popular option for homes with people who have mobility issues.
Thickness
The standard thickness is 1 ⅜ inches. This is the most popular interior door thickness, and it's frequently the only one available at home improvement stores. Door thicknesses of 1½ inches and 1¾ inches may be available at some stores. These are significantly thicker and are frequently insulated or constructed of hardwood.
Jamb
On pre-hung doors, the standard inside door jamb thickness is 4-9/16 inches. The door jamb is the frame that mounts to the wall and holds the door in place with hinges. This thickness is intended for use in a typical two-by-four wall which is made up of studs measuring 1½ x 3½ inches.
The thickness of an alternate jamb is 6-9/16 inches. It's made to accommodate two-by-six walls which are made up of studs that are 1⅕ x 5½ inches.
How Do You Frame The Rough Opening Of An Interior Door?
If you need to install a door in your home, you should first prepare the door’s rough opening. Below are the steps:
1. Decide whether to buy or build a frame.
If you have the expertise, time, and tools to complete the task correctly, it would save you money to build your door frame. But if you're unsure, buying a prefabricated door frame or prehung door would be a better choice. The prefabricated door is usually not that much more expensive, and it would save you a lot of hassle.
2. Know what type of wood to purchase.
Determine the sizes of woods to be used for the door framing components. The most common nominal size for wood studs is two-by-four, but two-by-six and other sizes are often used in home construction. A lumberyard or a home improvement warehouse store can provide you with the materials you want.
3. Determine the door's dimensions.
Consider what sizes and types of doors you will put in the room. If the door goes to a laundry room, for example, make sure it's wide enough to accommodate a dryer and a washing machine, preferably 36 inches.
4. Measure the opening of the doorway.
The door you wish to install will determine the size of the door opening. To accommodate the thickness of the jamb material as well as shims to plumb the jamb, an opening that's 2 inches wider than the door needs to be installed.
5. Cut the sole plate and studs to the appropriate length.
Don’t cut the top plate of a wall! Studs are the upright planks secured along the sides of the frame that support the wall, while a board that runs over the top of the studs is known as the top plate.
- Studs: Before building the studs, determine the height of the door. Cut two-by-fours to the height of the door plus 1 1/2 inches, an allowance for the top frame, and leveling the jamb.
- Header: Two-by-fours cut to original opening width.
- King Stud: This is a stud that extends from the bottom plate. It is typically a double plate.
- Jack Stud: This stud is affixed to the king stud, but because it supports the door header, it is shorter.
6. Cut the door's header
You need two two-by-fours of the same size as the original opening. Fasten them together with nails. To achieve the proper wall thickness of 3 1/2 inches, put 1/2 inch of plywood between the two-by-fours.
7. Put them together.
- Nail (12D) the ceiling joists or block to the top plate.
Click here to see this Grip-Rite 12D nail on Amazon.
- Drive the nails into the floor joists or blocks to secure the sole plate to the floor. Because the sole plate will be removed before the door is built, don't nail it to the floor between the jack stud placements. Insert the sole plate using masonry screws or any suitable fastener.
Click here to see these Tapcon screws on Amazon.
- Nail the king studs in place with 12D nails. To form a toenailed joint, drive the nails in at an angle, or use metal connectors to connect the studs.
- Take two two-by-fours and trim them to the same size as the door opening. Make a header out of them to go above the door. Nail these header pieces together once they're in place. The header should rest snugly on the jack studs and fit between the king studs.
- Cut two pieces (depending on the width of the door) of stud to fit between the top plate and the header. These are called the cripple studs. Secure the cripple studs to the header below them and the plate above them with toenails.
- On the inside corners of the jack studs, saw through the two-by-four sole plate. Take out the plate's cut part.
A video tutorial on constructing the frame of a rough opening is presented in the YouTube video below.
Final Thoughts
It's crucial to assess the rough door opening before placing a prehung door into a wall. Installing the prehung door will be impossible if the rough door opening is either too small or too big. If the rough opening is small, the prehung door will not fit into it. If it is too large, it will leave large gaps that will make installing the prehung door problematic.
Before you leave, take a look at some of our other posts to learn more about door improvement and design!