Cement render can be applied to metal lathing with a layer of building paper incorporated. When used on a timber frame wall this assists in containing the render behind the mesh but should not replace the breather membrane applied to the sheathing. This can be applied on-site, or created in the Benfield ATT factory in prefabricated panel form. The battens are fixed to the studs in the wall panels in order to maintain a cavity between the back face of the render and the sheathing. The cavity allows any water which penetrates the render to drain out and also vents to increase the safety margin against condensation risk. The cavity should incorporate cavity barriers and firestops at the positions required by Building Regulations.
The render materials can be site mixed or proprietary pre-mixed render can be used which usually requires only the addition of water. Proprietary render or textured cement finishes can also be applied to fibre cement or cement-bonded particleboard cladding boards which are fixed to battens on the face of the timber frame panel. Subject to the appropriate allowance for differential movement being made, joints between the cladding boards can be covered with scrim tape and a flush joint achieved.
