A guarantee board is a (virtually) waterproof hardwood plywood construction panel with a smooth, usually pre-primed top face, for which the manufacturer gives 10 to 20 years’ guarantee depending on the type. It is a popular panel for outdoor applications that must withstand years of wind and weather.
Application
The guarantee board is built up from bonded hardwood veneer layers, glued with a waterproof WBP adhesive (Weather and Boil Proof). This keeps the panel stable even under prolonged exposure to moisture, so it does not delaminate. The pre-primed top layer saves a priming coat and provides a smooth surface that is ready to be painted straight away.
Common applications include:
- Fascia boards along roof edges and gutters
- Cladding and external facade boarding
- Dormers, cheeks and side panels
- Canopies and overhangs
- Bay windows and other extensions
- Damp rooms where ordinary board would move
An important point to note: although the panel surface is primed, the cut edges become vulnerable after cutting to size. Untreated edges can absorb moisture and then begin to move or delaminate. Therefore seal all sawn edges immediately with a suitable edge lacquer or sealer, so the guarantee is preserved and the panel does not let in water.
Common sizes:
| Property | Value |
|---|---|
| Thickness | approx. 10 to 22 mm |
| Panel size | for example 244 x 120 cm |
| Guarantee | 10 to 20 years (depending on type) |
With its combination of durability, a finished top layer and a long guarantee, the guarantee board is a reliable choice for exterior finishing.
Related terms
- Facade
- Bricklaying
- Foundation
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