XPS Tile Backer Board 4-50mm
High-density XPS core with cementitious coating, 4-50 mm. A core component of the ICC-ES PMG-1804 listed tileable shower system. EN 13164 batch-tested, CE marked.
| Thickness: | 4-50 mm, custom sizes |
| Water absorption (96 h): | 0.8% |
| Compressive strength: | 361 kPa |
| Sound reduction (12 mm): | Rw,P 23 dB |
Overview
This is the XPS waterproof backer board the whole system is built on. A high-density XPS core, coated both sides with a cementitious layer over fiberglass mesh — stiff, light, and fully waterproof without a membrane.
One board, seven whole-house applications — see the full breakdown.
The numbers, from our own test reports: 0.8% water absorption after 96 hours of immersion. 361 kPa compressive strength. A 12 mm board carries a 1,842 N bending load and cuts sound by Rw,P 23 dB. Grade 0 mold resistance.
Three decades of XPS extrusion taught us where failures start: flex, moisture and seams. The coating, the mesh and the core density all exist to kill those three. Every batch is tested to EN 13164, and the reports are one email away.
Applications
Shower and bathroom walls on steel or timber studs
Wet room and steam room substrates
Pipe boxing, concealed cisterns and wall-hung toilet walls
Leveling uneven concrete (20 mm and up, dot-bonded)
Hotel bathrooms, residential retrofits and prefab bathroom pods
Fixing
On studs the board fixes straight to the frame — 12 mm on 300 mm-spaced steel studs is the standard shower build, and you step up to 20 mm where stud centres run wider. Specialized anchors and self-tapping screws with washers every 300 mm, no battens, no plywood backing.
Floors are a different job. Bed the boards in flexible tile adhesive, stagger the joints like ply, and hold a 10 mm gap off the walls. Then every joint, corner and penetration gets self-adhesive mesh tape bedded into waterproof sealant. That taped shell is the waterproofing — there is no membrane hiding under it.
Boards 20 mm and up double as levelling: dot-bond them over uneven concrete and the wall comes out flat in one pass instead of three. The full fixing sequence, with photos, is in our installation checklist — free with a sample request.
Sound Insulation Test: 89.5 dB to 54.4 dB
A live sound-level meter test. Watch the reading drop once our board goes up.
See where this performance matters most on our Applications page.
Complete the System
One material system, one fixing pattern — these usually ship together.