Posted on Date Posted by Dipak Patel on 27th Aug 2025
What Is Back Buttering a Tile (And When Is It Needed)?
What Is Back Buttering a Tile (And When Is It Needed)?
What Does “Back Buttering” Mean?
Back buttering is applying a thin, even layer of adhesive to the back of a tile in addition to the notched bed on the floor or wall. The goal is to increase contact, collapse ridges more effectively, and eliminate voids that can lead to cracking or hollow sounds.
Why It Matters
- Coverage: Helps achieve the recommended 80–100% contact (100% in wet or exterior zones).
- Strength: Fewer voids mean fewer weak points under point loads like chair legs and appliances.
- Flatness: Assists with large‑format porcelain where minor bowing needs managing.
When You Should Back Butter
- Large‑format tiles (≥ 600×600) and long planks.
- Natural stone, which benefits from full support to prevent cracks.
- Outdoor tiling and high‑traffic floors.
- Uneven substrates where full contact is harder to achieve.
How to Back Butter Correctly
- Use the flat side of your trowel to key a thin coat onto the tile back.
- Comb ridges on the substrate in one direction with the notched side.
- Press the tile firmly, then slide perpendicular to the ridges to collapse them.
- Lift a tile occasionally to inspect coverage and adjust trowel size if needed.
Match your tile and project to the right adhesive and consider a levelling system for ultra‑flat results.
Common Mistakes
- Skipping back buttering on big tiles—leads to voids and future failures.
- Combining ridges in different directions—makes collapse harder.
- Using too small a trowel—reduces coverage.
Bottom Line
Back buttering is a small step with a big payoff. If you want your tiles to last and feel solid underfoot, it’s worth the extra minutes.