Prova - BOARD PLUS - Waterproofing Tile Backer Board - 4' × 8' × 1/2"

PROVA BOARD^® PLUS is a lightweight, high-density tile backer board: a 100 % waterproof extruded polystyrene core, reinforced on both faces with fibreglass mesh and protected with a cement coating.

It fastens directly to the framing studs and gives a ready-to-tile bonding surface in wet areas. At 0.66 lb per square foot, a 4 × 8 ft board is a one-person lift — where an equivalent cement board takes two.

The XPS core absorbs no water by capillary action and supports neither mould nor mildew. It resists vapour pressure, which makes it usable where an ordinary board breaks down.

• 100 % waterproof XPS core — zero capillary absorption
• Fibreglass mesh and cement coating on both faces
• 0.66 lb/sq ft (3.2 kg/m²) — one-person handling
• 32 sq ft per board
• Mould and mildew resistant
• Resistant to vapour pressure
• ASTM E84 surface burning: Class A
• Insulating — R-value of 4.3 per inch of XPS core
• Working temperature from -45 °C to 60 °C
• Zero ozone-depleting substances
• Installs on walls, floors and ceilings, over wood or steel framing

⚠️ Thin-set mortar — read before installing

A premium polymer-modified thin-set mortar is mandatory. Pre-mixed mortar and mastic must not be used: they do not cure properly against a non-porous substrate.

Sealing the system

The board is waterproof throughout, the assembly is not until the joints are treated. Seal every joint, seam and pipe penetration with PROVA-SEAL™ and fasten with PROVA FASTENERS^®.

That is also the condition of PROVA's lifetime warranty: it applies when the board is installed as part of the complete system.

Can be used for

• Showers and tub surrounds
• Bathroom walls and ceilings
• Countertops and backsplashes
• Saunas and wet rooms
• Substrate for large-format tile and natural stone

Testing and performance