DIY Arch - Using the Etsy Arch Kit!

An easy weekend project for renters, beginners, and design lovers.

Rounded doorways instantly soften a space — they add character, warmth, and that subtle architectural charm you see in boutique hotels and Mediterranean‑inspired homes. The best part? You don’t need demolition, framing, or power tools to get the look.

Etsy customer after a picture of a shelf alcove.

Today, I’m walking you through how to install the Etsy Arch Kit — a lightweight, customizable system that lets you turn any square opening into a full half‑circle arch in just a few hours. The transformation is dramatic, but the process is surprisingly simple.

🛠️ What You’ll Need

Included in the Etsy Kit

• 2 custom arch pieces sized to your doorway (optional sizes to pick from)

• Pre‑cut to your wall thickness and opening width

Additional Supplies

• Construction adhesive (Liquid Nails or similar)

• Masking tape

• Drywall joint compound

• Joint tape

• Putty knife or trowel

• Sandpaper or sanding screens

• Optional: wall texture spray

• Paint to match your walls

  
  

📏 Step 1: Measure Your Doorway Correctly

This kit is custom‑cut, so accurate measurements matter. The seller requires three measurements per corner:

• Wall thickness at the corner

• Wall thickness 15 inches above

• Wall thickness 15 inches down the vertical side

• Doorway width at the top (round up to the next inch)

Pro Tip: Deduct ⅛ inch from your measurements to allow space for joint compound.

🧲 Step 2: Dry Fit the Arch Pieces

Before gluing, hold the arch pieces in place to ensure:

• They sit flush against the wall

• Your corners are close to 90°

• The curve aligns with the opening

If your corners aren’t perfectly square, don’t panic — you can correct small gaps with joint compound later.

🩹 Step 3: Glue the Arch into Place

Apply construction adhesive to the thinnest areas of the arch pieces (this keeps the surface solid for mudding later).

Press each piece firmly into position.

Use masking tape like temporary clamps to hold everything in place while it dries overnight.

🧱 Step 4: Tape & Mud the Seams

Once the adhesive is dry:

1. Remove the masking tape

2. Apply joint tape along all seams

3. Cover with joint compound

4. Feather the edges with a putty knife

5. Let dry, sand, and repeat as needed

You’re aiming for a smooth, seamless transition between the arch and your existing drywall.

🎨 Step 5: Texture & Paint

If your walls have texture, apply a matching spray texture before painting.

Once dry, paint the entire arch to blend it into the surrounding wall.

This is the moment the arch truly disappears into the architecture, and the space feels instantly elevated.

✨ That is it!

Don't forget a before & after picture! :))