Why Prime the Walls?
Probably the most asked question we hear. “The walls are already painted” Most walls today are painted with a flat latex paint which is extremely porous. The quality of the paint ranges from the the stuff (being nice here) that builders put on homes when they deliver them. You may know from experience that when you go to wash the walls the paint will come off or, in some cases, simply make the wall shiny the. Other times there is a paint primer on the walls.
Manufacturers of the wallpaper ALWAYS SUGGEST WALLPAPER PRIMER BE USED prior to application. Not doing so could void any warranty on the wallpaper, should there be a problem with the paper. Wallpaper primers prevent the paste on the paper from seeping through the builder’s flat and making the wallpaper a permanent part of your wall. Removal, when the time comes, is a nightmare, as there will be damage to the drywall requiring skim coating, repairs and more problems than you want. Wallpaper primer is a relatively inexpensive product selling for less than $20.00 a gallon. We recommend Shields white pigmented primer.
Never, use a alkyd primer on the walls. Doing so will require a latex wallpaper primer be applied over the Alkyd.
Prep Coats and R35- These products are used when additional “tack” is needed, say for example if you are hanging over glass, formica, glossy paint surfaces, etc. They should never be used to seal the wall as the wallpaper primer mentioned above.
Sizing the Wall- A confusing term as “sizing” was generally used back in the days of hanging over plaster walls. It is generally nothing more than wallcovering adhesive watered down and put on the walls. It supplies additional “tack” for the wallpaper to grip to. Frequently today people will call priming the walls with wallpaper primer “sizing” the walls. Now you know the difference!
Hanging over Old wallpaper. Sometimes it can be done in residential applications, however we don’t recommend it. In some cases where the wallpaper is well adheared to the wall and the walls are in bad shape you may want to consider this option. Rely on a professional to advise you if it is pratical. NEVER, EVER put wallpaper over wallpaper in commercial applications as it changes the fire rating of the wallpaper and can cause serious problems.
Blankstock lining paper- Generally required by Designer manufacturers like Osborne & Little, Cole and Son, Sanderson, Farrow and Ball, etc. This plain white paper helps provide a smooth surface for the wallpaper, more importantly it helps wick the paste and aids in drying time. It also helps minimize seams and provides a cleaner look. The downside is that it increases the costs as you are papering the walls twice.
There are many liners available used to help walls in poor condition where you want to mask the imperfections. Some are thick enough to be used over paneling and cylinder block walls. In many cases they can be painted in addition to being a great surface to hang wallpaper on.
Designer Papers Needing Selvage Trimmed. These papers are generally purchased from Interior Designers and require the edges be trimmed. They will not match exactly at the seams depending on the pattern. Many times papers machine trimmed will still not exactly match at the seam but still meet manufacturer’s tolerences.