Wallpapering corners and seams requires precision techniques to ensure smooth transitions and invisible joins. Whether working with inside corners, outside angles, or curved surfaces, mastering proper cutting, overlapping, and seam alignment is critical for a seamless look. Professional installers recommend slightly overlapping wallpaper in corners, using a sharp snap-off blade for exact cuts, and smoothing with a corner tool to avoid wrinkles or gaps. Matching patterns across seams and trimming excess with a straightedge helps maintain design continuity and achieve a clean, polished finish.

 

Table of Contents

How to Wallpaper Inside Corners | How to Wallpaper Outside Corners | Dealing with Curved Corners | Setting a Plumb Line for Adjacent Walls | Common Mistakes | Overlapping Wallpaper | Tackling Chimneybreast Corners | Finishing Touches | What is the right sized pattern? | Removing Old Wallpaper

How Pro's Wallpaper Inside Corners

 Inside corners are where the corners of the wall meet inside a square room. We make sure that there is gap between the wallpaper that we've pasted and the corner. We then follow these steps for inside corners.

1. When you begin wallpapering make sure you hang the first piece around 2 inches form the corner.
2. Measure the top the and the bottom gap between the wallpaper and the corner of the room. You'll notice that the one measurement will be wider than the other because walls are often not completely straight. Write down the bigger of the two measurements adding half a centimetre. 
3. On your wallpaper table fold the next section in half lengthways and again so that its easier to cut. 
4. Now mark the face of the wallpaper with two dots at the top and bottom using the measurement you took in step 2. If your wallpaper corner is on the left of mark from the right side and vise-versa for left 
5. Line the two dots up with a long ruler and cut a strip of wallpaper. You should now have a strip that is slightly larger than the gap you measure and will be left a small edge on the adjacent wall once its pasted.
6. Apply adhesive to the wall and match the pattern with the wallpaper that is already on the wall. 

Hanging wallpaper on inside corners can be challenging. Use the wrap-and-overlap seam technique for seamless joins on the adjacent wall. Next up we'll run through outside corners.

 

How to Wallpaper Outside Corners

An outside corner also known as an external corner is where the wall projects outward. This is common in hallways or where a room adjoins another room.

 When wallpapering external corners first of all don't panic, it will all go smoothly if you follow our guidelines and believe in yourself, don't attempt to wrap a whole piece of wallpaper around a corner. Walls are often not straight and a larger piece of wallpaper wrapped around an external corner will accentuate this. Instead break into two sections like below:

 

Section A

1. You should stat by wallpapering a strip near the edge of the external wall leaving a gap of anything between 6 -12 inches
2. Measure the top and bottom distance of the hung paper to the outside edge of the wall. Write down the largest of the two measurements and add 1 cm.
3. On your wallpaper table fold the next section in half lengthways and again so that its easier to cut.
4. Now mark the face of the wallpaper with two dots at the top and bottom using the measurement you took in step 2. If your wallpaper corner is on the left of the already hung piece, mark from the right side of the pattern and vise-versa for left.
5. Line the two dots up with a long ruler and cut a strip of wallpaper with a knife or scissors.
6. You should now have a length of wallpaper that is slightly larger than the gap you measured and will left a small edge on the adjacent wall.
7.   Apply adhesive to the wall and line up the pattern with the wallpaper that is already on the wall.
8.   Smooth out any crease with a brush.
9.  Because there will be half a cm of overhang you'll need to cut a horizontal line at the top and bottom so the paper can be wrapped around the wall.
10. Fold the overlap around the corner

 

 

Section B

1. 1. Now measure the width of the remaining wallpaper that you cut and add 1cm
   2. Take the measurement and mark it on the wall measuring outward from the edge of the wall.
   3. Use a laser level to line it up with the marking. This should give a straight line for your next length to follow all the way down.
   4. Apply paste to the wall and dont forget to go under and over the folded area from section A.
   5. Apply the wallpaper around 2mm from the edge of the wall over the top of the folded section
   6. Adjust the angle of the paper ensuring that the space between the laser level measurement and the edge of the paper is equal
   7. smooth out with a brush and trim any excess.

Dealing with Curved Corners

Curved corners can be tricky, but the right approach can make them work to your advantage. Leave more wallpaper than usual to accommodate the curve, ensuring enough material as you smooth it around the bend.

Use horizontal motions to smooth wallpaper around curved corners. Relief cuts at the top and bottom of the wallpaper ease application and allow it to flex and contour to the curve for a seamless finish.

These tips will help you handle curved corners like a pro, ensuring a flawless look regardless of wall shape.

Setting a Plumb Line for Adjacent Walls

Setting a plumb line helps hanging wallpaper straight, especially on adjacent walls. A plumb line ensures proper alignment. Use a weighted string or plumb bob to establish a vertical line for accurate application.

To set a plumb line, drop a weight attached to a string from the top of the wall to create a reference line. Mark where the string touches the wall for precise placement of the first strip. Older walls may not be perfectly square, so trust the plumb line for accurate vertical alignment.

Reposition the weight if the plumb line appears off during installation. This prevents the wallpaper’s left edge from becoming off-plumb, ensuring a straight and professional finish.

Common Mistakes to Avoid When Wallpapering Corners

Avoiding common mistakes is key to a successful wallpapering project. Use a smoothing tool to eliminate air bubbles. A seam roller presses down the edges for a secure bond, ensuring smooth and adhered edges.

Smooth wallpaper from the centre of the strip to avoid air bubbles, but avoid applying too much pressure to prevent damage. Ensure proper alignment at eye level to avoid noticeable mismatches.

By avoiding these common mistakes, you’ll achieve a professional and flawless finish on your wallpapering project.

Overlapping Wallpaper in Corners

Measure and ensure an extra ½ inch to wrap around the corner. For outside corners, measure the length needed and add a few inches for overlap.

The next wall panel should overlap the ½ inch extension from the previous one for a seamless look. This creates a smooth transition, avoiding visible seams and gaps. Handle excess wallpaper and paste carefully to maintain a neat finish.

Mastering the technique of overlapping wallpaper in corners will help you achieve a professional and polished look.

Tackling Chimneybreast Corners

Wallpapering a chimney breast requires a specific approach for a seamless and visually appealing result. Start by centralising the first strip based on the chimney’s vertical midpoint. For large-patterned wallpapers, position the most prominent design feature at the centre.

After centring the first strip, wrap wallpaper around both external and internal corners for a seamless transition. Alternatively, hang the first two lengths on either side of the centre line before continuing around the corners.

Following these techniques will help you tackle chimney breast corners with confidence, achieving a professional and visually appealing finish.

Finishing Touches for Professional Results

Finishing touches set a professional wallpapering job apart from an amateur one. Smooth the wallpaper into the corner and trim excess at the ceiling and baseboard for a clean finish. Trimming in the corner creates a tight fit for inside corners.

A trim guide while cutting helps maintain the desired overlap and preserve pattern integrity. Clean any excess paste with a natural sponge immediately to prevent drying.

Paying attention to these details ensures a polished and professional finish, making your wallpapering project stand out.

What is the right sized pattern for my room?

Choosing a wallpaper pattern its often helpful to see how it looks in your room or commercial space to feel confident in your vision. Whether a private buyer, an interior designer or otherwise House of Londinium enables you to see any of our Luxury wallpapers in your space with our digital view in your room option. Contact us to enquire further.

How do I remove old wallpaper from corners and walls

Removing old wallpaper can be done in a number of ways but it will depend on the age of the paper. Follow our guide on removing wallpaper from walls.