Description
Tiling over a timber floor fails at the substrate, not at the tile. Prima ceramic tile underlay is a cellulose fibre reinforced cement sheet made to sit between the two, giving the tile bed a rigid, dimensionally stable base that does not move with the boards underneath it.
The sheet is manufactured to AS/NZS 2908.2 and comes in an 1800 by 900 millimetre format at 6 millimetres thick, which covers 1.62 square metres and is still a two-person lift rather than a crane job.
Technical Specifications
| Product type | Cellulose fibre reinforced cement flat sheet |
|---|---|
| Standard | Manufactured to AS/NZS 2908.2 |
| Sheet size | 1800mm x 900mm |
| Thickness | 6mm |
| Coverage | 1.62 m² per sheet |
| Composition | Portland cement, finely ground sand and cellulose fibre |
| Application | Substrate for tiles over timber floors |
| Colour | Light grey |
Working With the Sheets
At 1800 by 900 millimetres and 6 millimetres thick, each sheet covers 1.62 square metres and weighs enough to be a two-person lift rather than a one-person one. Plan the set-out before you start so joints land where you want them, because cutting fibre cement to correct a bad set-out is slow work.
Cut using the methods the technical manual specifies and manage the dust properly. Cellulose fibre reinforced cement contains finely ground sand, and cutting it dry without extraction puts respirable dust into the air.
Where to Use
- Tiling over strip timber, particleboard or plywood floors
- Wet area floors where a rigid tile substrate is required
- Renovations where the existing timber floor stays in place
- Commercial fitouts tiling over a timber structural floor
How to Apply
- Check the subfloor — Confirm the timber floor is sound, dry and adequately supported before anything goes down.
- Lay the sheets — Set out with joints staggered, leaving the expansion gap the installation instructions specify.
- Fix down — Fix at the specified centres so the sheet is held flat across its whole area.
- Treat the joints — Fill and finish joints before tiling so the tile bed sits on a continuous plane.
- Tile — Tile and grout using a system suited to a fibre cement substrate.
Important Notes
- The sheet is a tile substrate. It is not a structural floor and does not replace adequate joists or bearers.
- Wet areas need the waterproofing system installed over the sheet, not instead of it.
- Cut with the methods the technical manual specifies and manage dust accordingly.
See the full flooring underlay range for related products.
