Do I Really Need Tile Backer Boards? The Questions You Were Afraid to Ask

The Basics

What is tile backer board?

Tile backer board is a semi-rigid panel used as a base for tiling. Unlike plasterboard or plywood, it will not warp or break down when exposed to moisture. It creates a strong, even surface that helps tiles stay secure long term. It protects your tiles from surface movement (so they don't crack), and can often hold more tike weight than aging plasterboard.

What is tile backer board used for?

Use backer boards anywhere you plan to tile, especially in bathrooms, showers, wet rooms, and kitchens. They protect against water damage, mould, and tile failure by providing a waterproof, dimensionally stable substrate.

What is tile backer board made of?

Different brands use different constructions. Marmox Multiboard uses an XPS foam core with a cementitious coating. Schluter Kerdi Board combines a rigid foam core with a waterproof surface layer. Orbry boards are foam cored and reinforced for strength.

Why use backer board for tile?

Tiles and grout are not waterproof by themselves. Backer boards create a reliable base that limits movement, blocks moisture, and reduces the risk of cracks and debonding. The result is a longer lasting tiled finish. You can also have confidence that the substrate your sticking tiles to (the backer board) has been specifically engineered and designed for this purpose, rather than just using the walls / floors / substrate that is already there and hoping for the best!

Do you have to use backer board for tile?

It is strongly recommended in wet areas and on unstable substrates. Tiling straight onto standard plasterboard or timber often leads to failures. Backer boards add stability and moisture protection.

Is tile backer board necessary?

Yes if you want durability in bathrooms, showers, or over timber floors. The upfront cost is small compared to the cost of replacing failed tiles later.

Should I use tile backer board?

Yes for wet rooms, showers, and over floors with movement. Even in dry areas, backer boards improve flatness and adhesion which helps prevent cracks.

Properties and Performance

Are tile backer boards waterproof?

Yes. Waterproof boards such as Kerdi Board, Multiboard, and Orbry are designed to resist water ingress. Always seal joints, corners, and fixings for full protection.

Can tile backer board get wet?

Yes, and unlike standard plasterboard, it will not disintegrate. Correctly installed boards remain stable even with regular moisture exposure. This makes them particularly useful in bathrooms and wet rooms.

Is tile backer board moisture resistant?

As above - yes. Moisture resistance is a key benefit, helping prevent hidden damp and mould behind tiles in bathrooms and kitchens. Think of it as your silent saviour keeping everything dry behind the scenes!

Do tile backer boards need tanking?

Most waterproof boards do not need full tanking, but you must seal joints, penetrations, and edges with waterproof tape or sealant to create a continuous barrier. For example, if you're screwing into them you should always cover the screw with waterproof tape to stop water getting in around the screw.

Is tile backer board fireproof?

No. Foam cored backer boards are not fireproof and should not be used as fire protection. Check the manufacturer data if fire performance is critical.

Is tile backer board fire resistant or fire rated?

Similar to the above, some tile backer boards carry limited fire classifications, but they are not intended as fireproofing. Use specialist cement boards where non-combustibility is required. Most foam cored boards are not classed as non combustible. Consider fibre cement boards for applications that require that rating.

Are tile backer boards heat resistant?

Yes within normal building temperatures and with underfloor heating. Avoid direct flame or extreme heat sources.

Are tile backer boards flexible?

Boards are generally semi-rigid. Thinner options like 6mm have generally have flex for minor irregularities, but they must be well fixed to prevent movement.

How thick are tile backer boards?

Common thicknesses range from 6mm to 50mm. We generally advise using 6mm to 10mm on walls, and thicker boards on floors for insulation and rigidity.

Installation Questions

How to cut tile backer board

Score and snap foam cored boards with a sharp utility knife and straight edge. For thick boards, use a handsaw or circular saw with dust control. Always wear appropriate PPE. They are designed to be both lightweight and easy to work with, so cutting them is generally considered easy and part of their design.

How to install tile backer board

Fix to walls or floors with suitable adhesive and corrosion resistant screws with washers. Stagger joints and seal all seams and penetrations before tiling.

How to install tile backer board on wall

Screw to studs at the specified centres, or bond to solid walls with tile adhesive. Tape and seal joints to create a watertight surface.

How to install tile backer board on floor

Bed boards into flexible tile adhesive over the subfloor, then secure with screws and washers. This creates an insulated, stable base for tiles. We actually have a blog guide about installing tile backer boards on floors which you can read here as a handy in-depth guide!

How to install tile backer board on concrete floor

Use a suitable tile adhesive over clean, level concrete, then roll the boards in and press firmly. Fix mechanically if the manufacturer requires it and seal joints.

How to install tile backer board in shower

Use waterproof boards like Kerdi Board or Orbry. Fix securely, then tape joints, corners, and fixings. You will have a watertight lining ready to tile.

How to fix tile backer board to wall

On studs, use screws and washers into timber or metal studs. On masonry, use tile adhesive and, if needed, frame fixings. Always seal joints. We created a handy guide for installing tile backer boards to walls which you can read here.

How to fix tile backer board to stud wall

Install boards horizontally or vertically per guidance, fix at recommended centres, and ensure edges land on studs. Tape and seal seams. For a more in depth guide, please review the "How To Guide" tab on our Orbry Board page.

How to fix tile backer board to brick

Prime if required, apply tile adhesive in full bed, press boards flat, and add mechanical fixings if specified. Seal all joints and edges. For a more in depth guide, please review the "How To Guide" tab on our Orbry Board page.

How to attach or secure tile backer board

Use the board maker’s screws and washers plus adhesive where recommended. Correct fixing pattern prevents deflection under tile load. For a more in depth guide, please review the "How To Guide" tab on our Orbry Board page.

How to use tile backer board

Install as the substrate before tiling. Once all joints, corners, and penetrations are sealed, you can tile directly onto the board.

How to seal tile backer board

Use waterproof joint tape with compatible sealant or thinset at seams, corners, and around screws and pipe penetrations. the baord itself doesn't need sealing, just anywhere where you are screwing it in, or creating joins between boards.

How to remove tile backer board

Carefully strip tiles, then unscrew or prise boards from adhesive. Expect some damage to the underlying surface during removal.

How much tile backer board do I need

Measure the area to cover and divide by the board face size. Add around 10 percent for offcuts and wastage.

Alternatives and Comparisons

Can you put tile backer board over drywall or plasterboard

Yes. Fix backer board over drywall or plasterboard in wet areas to create a waterproof tiling surface. Make sure you seal all joints and edges.

Can you use tile backer board instead of plasterboard

Yes. In bathrooms and showers, backer board is the preferred substrate because it will not soften or rot when exposed to moisture.

Can tile backer board be dot and dabbed

Yes with tile adhesive on flat, sound masonry, but mechanical fixings are recommended for strength and to meet fixing centres. Ideally would screw them to studs and add some tile adhesive to give them extra strength.

Can you use tile backer board on the floor

Yes. Use thicker boards on floors to add stability and insulation, especially over timber substrates or where underfloor heating is used.

Can I use 6mm tile backer board on walls

Yes. 6mm is suitable on walls when space or weight is tight. Use correct fixing centres and ensure the wall is plumb and true.

Can I tile directly onto cement board

Yes. Cement board is a tiling substrate. Seal joints and fixings, then tile with a suitable adhesive. This includes shower areas.

Do you have to put backer board under tile

On timber floors it is best practice. Backer boards reduce movement that can crack grout and tiles, improving longevity.

Do tiles need backer board?

In wet rooms, showers, and over unstable substrates, yes. Backer board is the most reliable foundation for a long lasting finish.

Finishing Questions

Can tile backer board be plastered or skimmed

We wouldn't recommend it. Backer boards are designed for tiling. Plaster may not adhere as intended and can compromise performance.

Can tile backer board be painted

This is possible with suitable primers and paints, but most installations are tiled. Always follow the paint maker’s substrate guidance.

Does tile backer board need priming

Most boards - including ours - do not require priming for tiling. However, if you are tiling with a known troublesome substrate or using the baords for somethings else, it's always worth check the board and adhesive manufacturer instructions before tiling.

Conclusion

Backer boards are the foundation of long lasting tiling. They deliver waterproofing, stability, and a flatter surface that helps tiles look better and last longer. Skip the shortcuts and start with a quality board for peace of mind.

Ready to choose your board? Explore our range of Schluter Kerdi Board, Marmox Multiboard, and Orbry Tile Backer Board and get your project off to a professional start.