While learning how to turn a square rough opening into an arched opening may sound like a very serious, expert-level project, it is usually quite simple. With the right tools and a little know-how, turning your square entryways into arched doorways is—in almost all cases—much easier than the average “do-it-yourself-er” thinks. Here are a few helpful hints for creating and installing an arched entryway into an existing square rough opening.
The Tools You’ll Need to Create Your Arched Entryway
• Crowbar or pry bar
• Pencil
• Hammer
• Jigsaw
• Handheld circular saw
• Workbench
• Drywall knife
Contrary to what most people believe about turning square rough openings into arched entryways, you don’t need any extravagant or expensive tools to get this DIY project done. You’ll need a crowbar or pry bar to remove existing trim and/or jambs, a jigsaw for cutting plywood, and a handheld circular saw to cut framing lumber. A pair of side-cutting pliers to pull out old nails, and a few other items for finishing the job, as listed above, will also help turn a square opening into an arched entryway. You’ll also need a workbench, where you’ll create your archway for installation at the top of the rough opening. If you plan on completing the job of turning your rough archway to a finished entry that’s door-ready, you’ll also need bendable drywall, drywall sealant, and a drywall knife.
The Materials for Creating and Installing a Doorway Arch
• 1/2” plywood
• 2×3” framing lumber
• 16-penny nails
• 1/4” bendable drywall
• Drywall sealant
• 1-5/8” drywall screws
To create the arched top to replace the square top of a rough opening, you’ll need two pieces of one-half inch thick plywood, and several pieces of 2×3” framing lumber: the amount and length of your plywood and framing lumber will depend on the width of your entryway from side to side, and the width of the doorway’s thickness. Typically, in homes built from 1965 forward will have entryways that are between 4-1/2–4-5/8 inches thick, while older homes will usually have thicker doorways. Houses built from 1900 to about 1965 with square doorways will have been constructed with plaster rather than drywall, and can often exceed the more modern 4-1/2-inch thickness.
If you’re creating an arched entryway in an older home, the doorway thickness could be five or more inches thick. Don’t let this deter you from creating an arched doorway in your rough opening—follow the instructions below and simply replace drywall with plaster where called for.
Steps to Creating an Arched Entryway in a Square Rough Opening
To begin, remove any existing trim or old parts and pieces of doorframe until you’re down to the rough opening without any debris, old nails, or other hardware in the entryway. Use your hammer to remove any old framing, casing, or trim nails, and use your crowbar or pry bar to carefully remove any old door casing or doorframe fragments from the rough opening. Now you can accurately measure the entryways thickness, and you’ll be able to tell if you’re dealing with drywall or plaster in the rough opening. To create the best arch for the entryway, measure the width of the entryway across several points to locate where its narrowest: If, at its narrowest point the entryway is 4-5/8 inches or less, continue with these instructions.
Making the Entryway Arch for a Drywall Rough Opening
Head to your workbench with your plywood first. The arch you’re creating should be a single inch narrower than the narrowest part of the rough opening. 1/2”-thick plywood and 2×3” framing lumber will work perfectly for constructing your archway.
Cut the plywood pieces based on how large you want your arch to be: most commonly, a one-foot arch is most desirable unless the rough opening is very tall and/or wide. For example, if your rough opening is five feet wide, and you’ve planned for a one-foot arch, cut both pieces of plywood so that they are five feet long and one foot wide. To cut the perfect arch, ensure the peak doesn’t come any closer than 1-1/2” to the top border of each piece of plywood (the finished plywood cut-outs should match exactly). After measuring the highpoint of the arch in the middle of each piece of plywood, mark it with a pencil. Use a sturdy piece of cardboard to create a traceable template for the arch shape you want (partial circle, eclipse, or half-circle). This way, if you make any mistakes you can simply erase lines or grab a new piece of cardboard if you cut incorrectly—that’s much cheaper than making a cutting error in plywood.
Use the cardboard to trace the arch onto your pieces of plywood, then use a jigsaw to slowly and carefully cut the arch into the plywood. Next, fasten each piece of plywood to either side of the rough opening. Enlist the help of a friend to hold the plywood arch frames in place as you drive 16-penny nails in at an angle through the plywood onto the rough opening. You now have the structure that your framing lumber will fit between, length-wise.
Next, measure the space between the nailed-in plywood arch cut-outs from one interior side to the other. This will tell you how long your framing lumber pieces should be. Use the handheld circular saw or table saw to cut your framing lumber. You’ll need one piece of lumber mounted every four to six inches across the top of the arch to give it the strength it needs to hold up over the years.
Applying Drywall to Your Arched Rough Opening
Instead of making your archway soak in drywall, and to avoid errors in smoothing drywall out with a trowel, use 1/4” bendable drywall to cover the rough archway opening from one end to the other. This saves a lot of time and the work you’d have to do later to sand down drywall to make it as close to perfect as possible. To adhere bendable drywall to the arch and rough opening, use a utility knife to cut a piece the length and width of your arch plus an additional six inches for either side of the arch. For example, if your archway frame measures 60 inches, you should cut 72 inches of bendable drywall. The extra foot of bendable drywall allows you to adhere it an extra six inches lower than the archway frame, so the drywall is mounted to the surface of the rough opening as well.
Ensure the bendable drywall is the right length, width, and shape with the help of your friend to place it against the arch. If everything matches correctly, the next step is to adhere the bendable drywall to the rough arch frame’s border and down the sides of the rough opening (six inches down on either side). Depending on the brand of bendable drywall, how it adheres will differ. Some brands come with a compound that automatically sticks, while others require a little water to activate a sealant built into the backing of the bendable drywall. Follow the instructions from the packaging of your bendable drywall to fasten it to the archway. Once it’s dry (if it requires drying), you’ll need to add a little extra security to the bendable drywall. For this, apply one 1-5/8” drywall screw every three inches across the entire archway border and an additional 1/2 foot down either side of the arch.
Final Steps
To match the bendable drywall you applied to the arch frame, add the same to the sides of the rough opening. Measure the length of each side (they should be the same), cut bendable drywall, and apply the same way, using 1-5/8” drywall screws every three inches to ensure total adherence to the rough opening. To cover any spaces between bendable drywall and the rough opening, mix some Mastic (drywall compound) with water until it’s the consistency of cake frosting. Apply the Mastic with a drywall knife, getting it into any cracks, and smoothing over any imperfections at the seams of the bendable drywall all the way down to the floor. You may need to apply Mastic one or two more times depending on how well your bendable drywall adhered, but if you do need to do this, wait at least two hours between applications.
Congratulations, you now have an arched entryway! Time to pick out an arched door from the ETO Doors selection, where you’ll find sizes and styles for any interior or exterior design type. Don’t see what you want? Design your own arched door with or without doorframe with ETO Custom Doors in four simple steps.
