External cavity walls

When constructing cavity walls please consider:

• the local climatic conditions. Choose correct bricks, blocks, mortar and joint pointing for the site
• the type of insulation used in the cavity. Is it full or partial fill? What width of cavity, if any, should be left clear? Does insulation need fixing back to blockwork?
• the type of wall ties used and spacing
• the position of damp proof courses - horizontal and vertical
• the strength of blocks and the load imposed on them
• that wall require restraint from buttresses, other walls, etc.
• pier sizes between openings and windows
• that walls may require movement joints
• that walls require fixing to floors and roofs with restraint straps
• that suitable lintols are required above openings and
• that padstones may be needed beneath beam bearings.

Please not that these guidance notes are for advice only and may not cover all situations. It is your responsibility to ensure that they are appropriate for use in your particular circumstances.