Installing a stylish backsplash is one of the most popular ways to upgrade your kitchen or bathroom. But before you start tiling, an important question needs answering: can you put backsplash over drywall?
The short answer is yes, you can install backsplash tiles over drywall. However, there are a few things to keep in mind to ensure proper installation and longevity of your backsplash. In this comprehensive guide, we’ll go over everything you need to know about putting backsplash over drywall.
What is Drywall?
Drywall, also known as wallboard or plasterboard, is a panel made of gypsum plaster pressed between two thick sheets of paper. It’s the most common interior wall surfacing used today for a few reasons:
- Cost effective – Drywall panels are an affordable wall covering option compared to other materials like wood or concrete. They’re easy to mass produce which keeps costs down.
- Smooth finish – The paper surface creates a nice smooth finish when seams between panels are taped and finished correctly. This even surface is ideal for directly applying paint or wallpaper.
- Easy to install – Lightweight drywall panels can be installed fairly quickly using basic tools like a utility knife, screws, and adhesive. Handy homeowners can tackle drywall installation and repairs themselves.
- Fire resistance – The gypsum core of drywall contains crystallized water molecules, which help slow the spread of fire. This makes drywall a popular choice to meet fire safety codes.
Drywall provides a budget-friendly blank canvas for interior walls and ceilings in most homes and commercial spaces today. But what about using it for a backsplash in the kitchen or bathroom? Let’s look at the pros and cons.
Can You Put Backsplash Over Drywall?
Installing backsplash tile over drywall is possible, but it does have some downsides compared to other backsplash materials and substrates.
Pros of Backsplash Over Drywall
Cost and availability – Using the existing drywall as a backsplash substrate saves money and time on materials and labor. Drywall is readily available and budget-friendly.
Smooth, uniform surface – New drywall offers a nice flat surface for applying backsplash tiles, which can result in a more uniform finished look.
Familiar material – Most homeowners and contractors are familiar with working on and installing drywall panels. No need to learn new specialty skills.
Doesn’t require waterproofing – Unlike other substrates like cement board and greenboard, regular drywall doesn’t require waterproofing prior to tiling.
Cons of Backsplash Over Drywall
Vulnerable to moisture damage – Drywall is made of a gypsum plaster core wrapped in paper facers. Exposure to significant moisture can cause drywall to break down, warp, and encourage mold growth.
Lack of rigidity – Drywall alone doesn’t offer enough rigidity and support for a long lasting backsplash installation. Tiles need a very secure surface to adhere to.
Difficult to make repairs – If cracking or damage does occur in the backsplash or drywall underneath, repairs require cutting away tiles and patching in new drywall which can be tricky.
Longevity issues – Due to vulnerability to moisture and lack of rigidity, a backsplash installed over drywall may be more prone to failure and have a shorter lifespan compared to other substrate options.
While using drywall as a substrate for backsplash tile can work, especially for very small non-wet areas, it is generally not the recommended practice. We’ll now look at better options to use behind a backsplash.
Best Substrates for Backsplash Over Drywall
There are a few good options available for preparing your wall surface for quality backsplash installation over existing drywall:
Cement Backer Board
Cement backer board, often referred to as CBU, is essentially moisture-resistant drywall. It’s made of an inert Portland cement interior core reinforced with fiberglass mesh on both sides.
Benefits of using cement backer board:
- Extremely moisture resistant and waterproof
- Provides very rigid support for tiles
- Can be cut, screwed, and finished similar to drywall
- Ideal substrate for most backsplash applications
Installing cement backer board over drywall for your backsplash is a small extra step that adds rigidity, moisture resistance, and long-term reliability.
Fiber Cement Underlayment
Fiber cement underlayment, such as HardieBacker®, provides another moisture and mold resistant substrate option.
Advantages of fiber cement underlayment:
- Waterproof surface
- Very rigid with no flex
- Smooth factory finish is ready for tiling
- Lightweight yet durable
- Does not promote mold growth
Screwing HardieBacker or similar fiber cement panels over the existing drywall creates excellent backsplash support.
Water-Resistant Drywall
Water-resistant drywall, often called “greenboard”, uses special additives and treatment to increase moisture resistance compared to regular drywall. It gets its name from the green paper facing.
Greenboard pros:
- More moisture-resistant than regular drywall
- Can be installed just like regular drywall
- Widely available and budget-friendly
- Familiar for DIY-ers to work with
Greenboard adds a higher level of moisture protection directly over your existing drywall.
How to Install Backsplash Over Drywall
If you decide to use the existing drywall alone as a backsplash substrate, or go with a water-resistant surface like those above, the general installation process is straight-forward:
Step 1: Prep the Drywall Surface
- Ensure the drywall is firmly attached to framing studs and will not flex. Screw down any loose areas.
- Fill any cracks or holes with drywall compound and let dry completely.
- Sand any bumps or mudded areas until smooth. The surface should be uniform.
Step 2: Apply CBU, Fiber Cement, or Greenboard (Optional)
- Measure area and cut substrate panels to fit using carbide blade score and snap tools.
- Attach panels with recommended screws into studs spaced 6-8” apart across entire surface.
- Tape seams with fiberglass mesh tape and thinset mortar.
Step 3: Prep the Surface for Tiling
- Seal the substrate surface with drywall sealer or appropriate primer.
- Apply thinset mortar evenly across entire backsplash area using a notched trowel.
Step 4. Install Backsplash Tiles
- Working in small sections, press tiles firmly into the fresh thinset mortar.
- Push tiles toward each other to minimize grout line spacing.
- Let mortar fully cure per product instructions before grouting.
- Apply grout between tile joints, wiping off excess.
- Seal grout once fully cured.
And that’s it! Take care to properly prep the substrate and use quality setting materials to achieve beautiful, long-lasting backsplash tile results.
FAQ About Putting Backsplash Over Drywall
Still have some questions about installing a backsplash over drywall? Here are answers to some frequently asked questions:
Can I use adhesive instead of thinset for the backsplash tiles?
Thinset mortar is strongly recommended, as it provides a much stronger bond than adhesives like mastic or silicone. Backsplashes require durable adhesion.
What about using liquid waterproofing instead of cement board?
Applying a liquid membrane over drywall can add moisture protection, but does not address the lack of rigidity or support drywall alone provides. Cement board is still a better choice.
Can I just use the same drywall that’s already on the wall?
You can, but it’s generally not advised. Unprotected drywall will be vulnerable to moisture damage long-term. At minimum use mold-resistant drywall. Adding cement board or fiber cement panels over the existing drywall is recommended for best results.
Should I take down the old drywall first?
No need to remove existing drywall if it’s in good shape and firmly attached. You can install cement backer board or another substrate right over it. Taking it down just adds unnecessary work and dust.
How is cement backer board different from cement board?
Cement backer board and cement board refer to the same tile substrate product – a moisture-resistant cement and fiber panel. “Cement board” is the more common generic term.
Can I use greenboard in steam shower areas?
Greenboard provides added moisture resistance but is not designed for continuous direct water exposure like in a steam shower. Cement backer board is better for these wet applications.
What do I do if my drywall has a glossy paint finish?
The glossy surface needs to be dulled down for proper thinset mortar adhesion. Lightly sand or use an etching solution so tiles adhere securely.
Conclusion
Installing a new backsplash is one of the most dramatic ways to transform your kitchen or bath. While it’s possible to install backsplash tile directly over existing drywall, moisture resistance and rigidity issues make cement backer board or fiber cement underlayment better substrate options in most cases.
However, if you take care to properly prepare the drywall surface and use quality setting materials, backsplashes over drywall can be done successfully. Just be aware that vulnerabilities to moisture and lack of support do exist when using drywall alone behind backsplash tiles.
We hope this guide has helped explain if and how you can put backsplash over drywall. The extra effort to install cement board or other suitable substrate will provide increased reliability and lifespan for your new backsplash. Done right, you’ll have a beautiful, high-performing backsplash installation that will upgrade your space for years to come.