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Wallpaper Basics

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By Tim Carter
©1993-2010 Tim Carter

Summary: Wallpaper must be applied over a sound foundation, or it will reveal every defect left beneath its beautiful face. Good wall prep is a required first step, just as when you wish to paint. Walls or old paper must be clean, sized and sealed, and wallpaper must be allowed to relax before hanging. Learn the basics here and get your wallpapering off to a head start.

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Wallpaper, Wallpaper Installation Tips, Resource Books

Back in the latter 70's, I was a wallpapering machine. My wife Kathy and I had just moved into our second house, a monster three story, five bedroom, frame house. Kathy loves wallpaper. I must admit, I to like the feel it gives a room or hallway. Anyway we installed wallpaper in the dining room, kitchen, entrance hall, main stairwell, second floor hall, and one wall of our bedroom. With Kathy's help, I'll bet I put up 100 or more rolls.

I found the work very therapeutic. Being a detail oriented person, I enjoyed cutting around ornate woodwork and working the seams. Kathy was fantastic at getting the paper pasted and precut.

Rare Errors (say that fast three times!)

It is important to realize, that I had no training whatsoever in hanging wallpaper. I just tried it. Believe it or not, I lucked out. There were few problems. Little did I realize at the time, failure could have struck at any moment. Paperhanging is both a science and a craft. Left to amateurs, problems can and will arise.

Wall Preparation - The Key

When was the last time you really read the label on a paint can? Come on, be honest. Virtually, every set of instructions includes a phrase similar to "...apply to a clean, dry, surface." Read a little further and you will probably see something to the effect regarding the proper use of primers. Wallpaper is no different. The key to a successful wallpapering job lies in its foundation, the wall surface.

Wallpaper can be very unforgiving. Smooth papers will telegraph every pimple, crack, depression, or defect the next day. Bumps you never realized will be highlighted as soon as the paper dries and stretches itself over every piece of sand or grit.

Dust, dirt, grease, water soluble stains, etc. can cause major problems. Dust will cause the paper to simply fall from the wall. It gets between the primer and/or adhesive and the actual wall. Grease will produce the same results. The moisture in the adhesive can dissolve colors found in stains and make them bleed right into the paper.

All of these possible failures and problems are lying there waiting for the unsuspecting rookie. Make a mistake and $300 - 400 worth of paper can be trashed in a day!

Cleaning - Think Glass!

One of the best things used to clean glass is ammonia. It just so happens that is probably one of the best cleaning solutions for wallpaper preparation. Simply mix 1 part of ammonia with one part water.

Avoid soaps that contain phosphates. Even after rinsing, a small amount of phosphate may remain on the wall. This will react negatively with sizing or wall primers causing them to bond poorly to the wall.

Primers - Sealers - Sizing

Wallpaper must resist the force of gravity to stay on the wall. However, its grip on the wall mustn't be so strong as to damage the wall in the event you wish to remove the paper at a later date. This is a tough balance to achieve. Primers, sealers, and sizing are designed to create the necessary base so that adhesives can stick well and that wall coverings can be removed with little damage to the wall surface.

Sizing - What Does it Mean?

I remember hearing the salespeople say at the wallpaper store that I needed to "size" my walls. I asked what it meant. They just pointed to a box and said it must be put on the wall. No one, at that time, could give me a clear answer as to its purpose.

Wall sizings are compounds that act like sealers. They equalize porosity. That is, they allow the wall paper adhesive to dry uniformly. Sizings also are supposed to provide extra bite. They also are meant to enhance the adhesive's holding power.

There are three basic forms of sizing compounds: cornflower and starch, pine flower and cellulose, or thinned down clay based adhesives. One characteristic that all sizings share is that they do little or nothing to protect the wall surface below for future removal of the wall covering.

The cornflower and starch sizing compounds should only be used on surfaces that have a very good high quality latex or oil based paint surface. Never use this sizing compound beneath a non-breathable wallpaper. Mildew may become a HUGE problem.

Cellulose and pine flower sizing compounds are much more resistant to mildew. They aren't like the starch which is basically the equivalent of "filet mignon" to mildew.

Homemade sizings simply refer to using a thinned down on-site adhesive. You would typically thin down the adhesive to the consistency of a thin latex paint. If a clay based adhesive is being used, the clay will act as an excellent base to absorb the water in the wall covering adhesive. This will speed up the drying process.

The act of sizing a room for wall paper is a process in and of itself. Once the walls are clean, smooth, and ready to go, you apply the sizing all at once. Begin applying the sizing at the spot you intend to begin wallpapering. That way the sizing maybe will be dry when you are ready to go.



Click here to watch Tim's video on wallpaper installation.


Primers & Sealers - A Must!

Let's say you have a new drywall wall you wish to wallpaper. If you do not apply a high quality primer/sealer, you (or a future homeowner) WILL ruin the drywall when they try to remove the wallpaper.

There are several different types of primers and sealers. You can purchase an acrylic one that has pigment in it. This product can be used on just about any wall surface. They are fantastic, especially if you intend to use a see-through wallcovering (many are!). Usually they clean up with water.

Clear acrylic sealers can also be purchased. They work great on existing wallpapers and vinyl wall coverings. However, if you use a see through wallpaper, you may see the old wallpaper after your new paper dries. Be sure to ask if your new paper is semi-transparent.

Oil based quick & slow dry primer sealers are also available. They work well. However, it is not advisable to use them over existing wallpapers and vinyls. The oils in the product may dissolve the inks in the previous wallcoverings. Also, some ingredients in these sealers are actually food for mildew.

Marks on walls or wallpaper that were not removed during the cleaning process may cause a problem. The adhesive may dissolve the color in the stain and cause it to bleed through the new paper backing. Use a standard stain killing paint for this job. After it dries be sure to put the regular primer/sealer over it before you paper. These stain killers are not approved wallpaper primers. They just kill stains.





Comments:

Rebecca
09 Jun 2008, 03:34
Hi

We sized our walls but after a few attempts at hanging wallpaper, we had to give up. We now can't attempt it for another three weeks due to time. Will we have to re-size the walls again or now that we've done them once, are they ok?

Thanks
Lisa
11 Apr 2009, 21:28
I want to remove my wall paer and paint my walls. The paer is peeling off fairly well but how do i remove the sizing from the walls?
Jerry
03 Aug 2009, 15:17
I am a third generation carpenter who was building a pool pump shed for some elderly neighbors. The neighbors loved my work and asked if I remove wall paper. I have removed my share, don't like doing it, but I had a few days before my next job started, so I agreed to take on the project. I perforated the wall paper, drenched the walls with DIF, replaced the blade in my 4-inch scraper and within about 4 hours the patterned layer of wall paper was removed. Unfortunately the backing remained on the walls. I ran my perforating tool over the backing and drenched with DIF again. This began an eight-hour task of scraping inch by inch. Once through the backing, there was another layer of backing and another 8 hours of scraping. Finally I reached the glue which with more DIF and a scrubby eventually came off. 10 hours over my original bid, the walls have now been skimmed and sanded, and are ready for primer. The customer who thought I'd be done within a day or so, is screaming at me because the job has taking three times longer than I predicted. I'm over my bid, working for free, and wondering what kind of demon wall paper I ran into? Did I mention that the wall paper was also on the ceiling? By the way, the customer says the wall paper was hung in the 90's, but I have only experienced paper this stubborn from the 40's and 50's. Did they get a deal on some 40's remnant and hang it in the 90's?

Confused, tired, and minus a good customer,
Jerry
Simon
29 Oct 2009, 04:04
How long can you leave size on a wall before you apply the wall paper

days - weeks
Joanne L Brown
29 Dec 2009, 19:29
i removed my wallpaper and intend to re-wallpaper. the walls were sized before the initial wallpapering. Do i have to size again? if there is sizing left, can i leave it on
juliana
30 Dec 2009, 20:35
Hello,
I have sizing in a bottle dated 1993. Is it still ok to use?

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