Do You Prime Drywall Before Tiling? [Yes! What To Do]


Tiling is a great way to improve or update the look of your home. It is essential to make sure you take all of the necessary steps to promote longevity with any tile installation.

Whether you are installing tiles as a backsplash, focal point, or in the bathroom, you should always prime the walls before installing them. This ensures that the tiles will properly adhere to the surface and prevent future problems. These problems could involve expensive issues to remedy, such as mold or mildew or loosened and falling tiles.  

Follow the steps outlined in this article to prepare and prime your drywall for a professional tiled look.

The Function Of Primer

While you may be tempted to skip the primer, most use it when tiling, wallpapering or painting to get the best overall results. Primer not only allows your work to last longer but helps to avoid future potential repair issues.

Primer Reduces Porosity For Better Adhesion

Drywall is absorbent and porous, and therefore anything wet will be absorbed by it. 

When you prime walls, the primer soaks into the drywall, filling in the pores and strengthening the surface. The drywall will increasingly become more resistant to moisture and temperature changes.

Priming over skim-coated walls, joint compounds, and drywall mud creates a surface that other materials, such as tiles, can adhere to. 

Priming prevents the drywall from absorbing any glue adhesives prematurely. Tiling glues need to dry slowly on an even and nonporous surface for optimal adhesion.

In regards to painting, primer will also cover stains and repaired spots so that topcoat paint has a consistent look and even color distribution. 

How To Prime The Drywall Before Tiling: 5 Steps

By following the steps outlined below, you can successfully prepare and prime drywall for tile application.

1. Choose A Primer For Tiling

Choose a primer that offers moisture resistance or is formulated for multi-surface applications. This is to ensure that you are using a primer that works well with tiles. 

Refer to the primer’s informational label.

2. Prep And Sand The Drywall

Preparation

Repair any damage such as gouges or scratches with drywall paste or mud to create a smooth and flat surface. Inspect the drywall to ensure that it is securely nailed or screwed in.

If necessary, remove switch plates, molding, outlet covers, and so on from the area that will be tiled.

If not already done so, use drywall tape on the joints and seams to strengthen the connection points. Allow this to dry, if necessary, before proceeding.

Sanding

  1. Cover nearby furniture and wear eye protection and a mask. 
  2. Use a pole sander with 100- to 120-grit sandpaper on the drywall. Sand a few inches beyond the scope of the tiled area. 
  3. Move the sander in a push and pull motion with consistent pressure. 
  4. Move over drywall mud and seams to create a flat surface.
  5. Finish the area with 150-grit sandpaper.

3. Clean The Walls

Remove sanding dust with a hose and suction attachment. Run dry, dark-colored cloths over the walls to remove any fine particles.

Make a cleaning solution in a bucket of one gallon of water with 1-cup of vinegar:

  1. Use a clean, damp sponge to wipe down the drywall, removing dust. 
  2. Rinse the sponge and repeat as needed. 
  3. Make a new solution if the mixture becomes dirty.

Conversely, trisodium phosphate (TSP) can be used to clean the walls. This is a hazardous substance, so follow all label precautions.

4. Dry The Area

Open windows and use a fan to circulate the air and dry the walls. 

This could take a few hours, and you will be able to observe if the walls are dry by looking at the mud and seams. 

If these areas are the same consistent color, they should be dry. Any variances in color will indicate that moisture sits there.

If in doubt, wait a full day before moving on to the next step. You want to avoid trapping moisture in the wall.

5. Prime The Walls

Using your chosen primer, refer to the labeling for application and drying times.

Tape off or cover any items and areas that you wish to keep paint-free.

To apply primer, follow these steps:

  1. Dampen the paintbrush or roller with water (water-based primer) or mineral spirits or paint thinner (oil-based). This allows the tool to absorb the primer evenly. 
    • Squeeze out the excess liquid.
  2. Apply the primer to the drywall. Prime a few inches beyond the scope of the area that you wish to tile. 
    • When putting primer on the paintbrush or roller, wipe off excess paint and apply it with consistent, even pressure.
    • Use the paintbrush to apply the primer to corners, edges, and around the trim.
    • Use the roller for larger areas. 
  3. Let the primer dry so it can seal the drywall for tile application. 
    • If the primer appears patchy, you will want to make sure all parts of the wall are primed for optimal adhesion. Apply a second coat, if necessary.
  4. Once dry, sand the primer with fine-grit sandpaper. This roughens up the surface for tile adhesion.
  5. Vacuum and wipe down the primed surface. Make sure it is completely dry before tiling.

What To Do If The Drywall Is Already Painted

If the drywall already has a primer on it, you still should repair and clean the wall before tiling.

Blue board drywall that is commonly used in bathrooms, is water-resistant, but not waterproof. Its surface should still be primed for optimal tile adhesion. 

If the drywall has top coat paint on it, especially semi- or high-gloss, then you should remove the paint before tiling. The tiling adhesive will not adhere well to any top coat paints.

This is because even if it is not visible, paints have ingredients that make the surface “slippery”, and the tiles are more likely to loosen and fall off over time.

Removing top coat paint is a laborious task but to ensure your tile sticks, it should be done. 

If you are not using a professional to remove the paint, you can try the following techniques:

  • Paint at least two coats of primer over the topcoat (easiest method)
  • Paint scraper
  • Wire brushes
  • Paint and varnish remover
  • Sandpaper, disc sander, roto stripper, or electric paint remover
  • Heat gun

Conclusion

Priming drywall before tiling is paramount. If you do not prime the surface, the wet mortar or glue might soak into the drywall. If it does, you may trap moisture in the wall, which will create issues such as mold or mildew, a weakened grip, or peeling or falling materials.

Lisa Burlison

Lisa is a freelance blogger, literacy specialist, teacher, and self-published author with a vast DIY experience. When she’s not writing for PlumbJoe, Lisa enjoys testing homemade cleaners and doing repairs around her home. Her other hobbies include birding and bicycling.

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