Caulk Before or After Wallpaper?

Wallpapers are the ultimate room changers since they are the most immediate way to introduce color, pattern, and texture into a room. However, mounting requires expertise to protect the integrity of the wall. A common question for interior decorators is whether caulking should come before or after putting up the wallpaper. 

Caulking before wallpaper is necessary to prevent the wallpaper from splitting, peeling, or puckering. Caulking before also protects your wall from scratches, stains, and structural damage caused by mildew growth. It also facilitates easier mounting and removal. 

In this article, I will explain why it’s best to apply caulk before mounting wallpaper. I will also offer important caulking tips before hanging wallpaper to ensure the wallpaper stays in place for longer.

Why You Should Caulk Before Hanging Wallpaper

wallpaper

Here are a few reasons you should consider caulking before hanging wallpaper:

Prevent Wallpaper From Splitting

Caulking refers to making surfaces air and water-tight by sealing them with a filler. This filler is usually an adhesive that can protect surfaces from water, mold, mildew, and damage. 

The primary reasons you should use caulk before applying wallpaper to your walls are:

  • Seal any gaps between walls and skirting.
  • Seal gaps around windows and doors as well as ceilings and walls.

The essence of caulking is that some cracks and gaps may grow over time, which affects paint, wallpapers, and other types of decorations. Decorator’s caulk is flexible and thus flexes with this movement without cracking. Active cracking does not only crack the plaster; it splits the wallpaper.

Prevent Wallpaper From Peeling and Puckering

At times, even professional decorators face challenges hanging wallpapers. The main challenge is a wallpaper peeling or pulling up as it dries. A little caulking can help solve this problem. Running caulk along all edges of the wallpaper and then smoothing with a finger or wet sponge removes any imperfections.

If your old wallpaper is starting to peel, do the following:

  1. Peel back the loose sections.
  2. Apply adhesive caulk under the paper.
  3. Smooth the paper against the wall to strengthen the bond and prevent the wallpaper from peeling off.

Smoothing Surface Imperfections

Decorator caulk is used before decorations to get rid of unsightly seal blemishes on crown molding, baseboards, nail edges, and other imperfections. Decorators caulk is the right choice to hide these imperfections and other gaps between the wall and finishes. 

The caulk also prevents moisture penetration into the walls, as moisture can cause your wallpaper to peel or pull. To prevent this, ensure that the caulk completely dries first and any bumps are properly smoothened by sandpaper before laying wallpaper over it.

Protect Your Walls

Caulking before sticking your wallpaper can protect your walls. The layer of caulk that you apply before mounting the wallpaper creates a buffer between the wall and the wallpaper. It is important to note that some wallpaper adhesives contain chemicals that can easily stain the wall or act to expand existing cracks. 

layer of caulk to protect the wall

Caulking also reduces the amount of air and moisture that gets trapped between the wallpaper and the wall. This helps control mold growth and mildew in the space between the wallpaper and the wall.

If mold and mildew are a major problem for your walls, you may consider products such as Zinsser and Kilz primers for mold and mildew management. Mold and mildew can make your wall soggy, potentially leading to structural damage, and applying that caulk layer before sticking the wallpaper will mitigate this risk.

Easier Installation and Removal of the Wallpaper

Caulking before applying wallpaper can make the installation process much easier, preventing the wallpaper from sagging and dropping as it dries. By holding the wallpaper in place and securing its edges during installation, the caulk allows the stick adhesive to dry naturally, which minimizes its chances of shrinking and puckering. 

Wallpapers are not permanent, and you may want to change them over time. The caulk layer protects your wall from stains and scratches during wallpaper removal and simultaneously protects the back of the wallpaper from staining during removal. Since the caulk layer is soft, it is easier to peel off the wallpaper during replacement.

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How To Caulk Before Installing Wallpaper 

Here are a few tips to apply caulk before wallpaper:

1. Clean and Dry the Area You Want To Caulk

Make sure that the area you want to caulk is clean. Sandpaper can be used to smoothen any rough patches and make cleaning much easier. More attention should be paid to the zones with which the wallpaper edges will align. 

After sanding, you can also consider washing the area with a wet sponge and leaving it to dry before caulking since a clean surface enables caulk to adhere better.

2. Lay the Caulk

To apply caulk to your walls: 

  • Fill the caulk gun and carefully and thoroughly apply the caulk in all target areas. A smooth gun motion at even speeds will ensure an even application.
  • After applying the caulk, use your finger or a soft sponge to smooth it out. Smooth the caulk as soon as possible before it dries. The main areas where the caulk should be laid include joints, cracks, and nail or screw holes on the wall.
  • Caulk along the edges where the wallpaper will fit. A wide bead of caulk should be placed around this edge of the wallpaper. This caulk will help hold the wallpaper in place as the sticking adhesive dries.

If there are any electrical outlets or switches in the wallpaper area, run a caulk bead around them. This will ensure your wallpaper adheres properly to the edges of the outlets while ensuring a uniform look.

canvas textured vinyl wallpaper installation with squeegee tool

3. Leave To Dry

After laying and smoothing the caulk, wait at least 2 hours for it to cure and dry completely. If there are any bumps, divots, or lumps left over from caulking, you can add them down with a bit of fine-grit sandpaper. 

After the surface is even and smooth, you can proceed with the wallpaper mounting.

Final Thoughts

Caulking a wall surface before mounting a wallpaper has numerous benefits. The process safeguards both the wall and the wallpaper. Caulking reduces the amount of moisture and air trapped between the wallpaper while preventing mold growth in the space. 

It is also important to note that this process protects your wall from stains and scratches during wallpaper removal.