How many rolls of wallpaper do I need? , example: perimeter 8.50m by wall height 2.1m = 4 Rolls
Don’t Just Wrap The Paper Around Corners.
When you get to the corner and need less than a whole strip of wallpaper to finish the wall you should cut the paper. If you were to simply continue around the corner with the same piece of wallpaper strip as on the previous wall it will more than likely sag or tear. What to do is measure the distance to the corner of the wall and then add about 12 mm. cut the strip the width of your measurement. Cut the strip into 2 lengths. Hang the measured strip and it will overlap onto the next wall slightly.
Start Level & Straight.
Measure the remaining strip that you have cut. Pencil a plumb line on the adjacent wall that is the width of the second piece minus 25 mm. Measure this distance from the corner and draw a plumb line. Hang the second strip in alignment with the pencil line.
Always Align Edges.
The paper has overlapped both ways in the corner. Now cut through both overlaps on one wall getting as close as you can to the corner using a straight edge and a utility knife this is called a double cutting. Take away the top piece of wallpaper. Now peel away the paper underneath leaving the top layer. Smooth the edges down to be sure they adhere to the wall.
Using professional techniques such as this one when hanging wallpaper will make it look better and it will last longer.