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Wallpaper Adhesives, Wallpaper Seams

Double cutting seams is a delicate matter. But a sharp blade and smple experience will yield a seam that's almost impossible to find.

Overworking a seam or “worrying” a seam — Turner says some installers try to fix a seam by rolling it too many times and end up making things worse. The roller can stretch the paper, or create a shiny area by burnishing the paper or fabric. Also, too much adhesive can be pushed out from behind the paper, causing the seams to lift.

“Overworking a seam can cause the color to bleed, pigments to stick to your roller, or the foundation underneath to be stressed so much that the underlying paint layers fail,” Olsen says. It can also cause twin-ply materials to delaminate.

Turner says these problems can be avoided if the wall is dry, adhesive is used sparingly and booking times are sufficient, he says. “The more you play with it, or worry it, the worse that seam’s going to get.”

Stretching/Shrinkage — The more wood pulp there is in the product, the more likely it is to shrink, and stretching any wallcovering is an open invitation for shrinking, Turner says.

Moisture — If the sponge is too wet when you are wiping down your paper, water can get behind the seams and lift them.

Contrasting white seams when using dark wallcoverings — These white gaps have been a big frustration for professional paperhangers and solutions are hotly debated. The problem is especially evident if the paper is cut with a dull trimming device, leaving a fuzzy white edge. Duvall uses an acrylic paint and a sea sponge to color the end of each roll to match the background of the wallpaper. Olsen rubs chalk into the ends of the rolls with a piece of terry cloth and rubs away the excess with a sea sponge. Turner won’t use paint, marking pens or chalk. Instead he tints the primer so the color matches the wallcovering substrate, but he doesn’t guarantee that a wallcovering’s white substrate will not show. “I am the lone voice in the woods on this one,” he says.

New Products Can Prevent
Unsightly Seams
Responding to these concerns, Eisenhart Wallcoverings Co. developed Seam Solution, a wallcovering that is made with a gray substrate. The gray edges blend in with darker colored papers, masking the seam. “That’s been received very well, especially by professional paperhangers,” says Bruce Schott, Eisenhart’s vice president of enterprise resource planning and operations.

Schott says the company has also developed a new product called Paperez, which is hung on the wall dry. It does not absorb water and will not stretch or shrink, eliminating seam separations. The product is scheduled to become available in March.

To install Paperez, roll Roman’s EZ Hang adhesive onto the wall with a paint roller first, then hang the dry sheets. The paper is thicker and softer than most, so it’s easy to handle and does not tear easily. It’s dry strippable too, coming off the wall cleanly in full sheets. An entire room can be stripped in 20 minutes, Schott says.

Different Kinds of Seams
Professional paperhangers must be knowledgeable about the different kinds of seams, which are used in different situations.

• Butt seam — The most common seam, it is formed when two strips of paper are hung edge to edge.
• Wire seam — A slightly overlapped seam, it is used when the wall surface is uneven or if the paper has a wavy edge.
• Spring-loaded seam — This seam is created after a wire seam has set up for a few minutes. Pull the seam apart gently, then allow the edges to spring together, creating a smooth butt seam.
• Double cut seam — To form this seam, use a razor blade to cut through both layers of overlapped or untrimmed papers. Remove the cut end of each strip and join the seam.
• Wrap and overlap seam — Used to realign crooked corners, the seam is created when the paper is wrapped around a corner. Overlapped seams should be secured with vinyl-over-vinyl adhesive.
• Mitered seam — This seam is needed when hanging wrapped soffets and borders, and involves double-cutting the paper at a 90-degree angle.

Seam Tips
The double-cutting technique can be used to keep seams tight. Thomas tells his crew to double-cut the seams at a very slight angle if it looks like the wallcovering is going to shrink. Even if the paper does shrink back a bit, that angled cut allows the seams to stay tight.

Another method of preventing open seams, called the Velcro technique, involves applying, about an hour before installation, a thin layer of diluted clay adhesive directly to the wall where the seam will fall. The coating of clay will lock down the seams before shrinkage can occur, Duvall says.

Proper use of the right tools can also help paperhangers make a perfect seam.

Duvall says a lot of paperhangers are moving away from seam rollers and toward plastic smoothers, but she won’t give hers up. She uses a mahogany seam roller for screen prints, a bone or poly roller for everyday pre-pasted papers and a metal roller on fabric-backed paper or commercial wallcoverings.

In the end, experience is the best guide. Wallcoverings are made with a wide range of materials, weights and thicknesses, and paperhangers have learned to get a feel for what kind of adhesives, tools and techniques to use.

When in doubt, phone the manufacturer and then test the product at home, Duvall advises. “Even though we’re professionals, there’s nothing wrong with calling and asking.”