Cladding Design Detail

This section provides build up drawings for different cladding scenarios and is one of the most popular areas of our site. You can link through to pages dedicated to each situation or download a single sheet version in pdf format to store for future reference.

Drawings are indicative only and are not to scale.  The information is for guidance only.  You may need to consult a suitably qualified engineer depending on the situation, imposed loads and likely wind loads.

Cavity, structural support and battens

• Ventilation cavity shall be a minimum of 21mm
• Vertical cladding battens with top edge machined at an angle will help shed water into the cavity.
• Battens need to be made from durable timber e.g. softwood pressure treated for a BSEN335:1 use Class 3 application to give a 30 year desired service life is ideal.
• Battens are normally spaced at 600mm centres.
• For high moisture content species like green oak use 400mm centres.

Timber cladding should provide adequate weather protection for the buildings. However, it must be assumed that not all wind driven rain will be deflected. As a consequence, a well ventilated, free draining cavity should always be included in the detailed design.

Whether a solid masonry or timber frame structure, TDCA recommends that this cavity shall be a minimum of 21mm wide. However, the width of cavity is generally decided by the style and width of the cladding board. The more open the cladding style the wider the cavity required to protect against moisture penetration.

On timber frame buildings, the minimum sized batten (21mm) may be used so long as its position coincides with wall studs.

Cladding membrane

Timber frame properties: The inner wall structure should be fitted with a breather membrane. This serves to seal the building against damp and weather penetration. As such it should be highly durable and tear resistant in accordance with Type 1 membranes in BS4016.

Masonry: Fitting a breather membrane between cladding / battens attached to a property with cavity walls is not essential.

Where cladding is fitted to an existing building with solid walls then to prevent water penetration the wall should be given a waterproof coating or a waterproof membrane or wax treated insulation board should be fitted.

Specification sheet downloads

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