Careful attention to joints is needed to ensure that the joint fulfils both architectural and practical requirements.

Many details are available, but those shown below are some that have been used over many years and found to be successful.  More elaborate or extreme details shown, for instance, on an Architect’s drawings should only be considered in the light of what is known to be efficient.

The outer and second seals shown are usually ’gunned’ mastic.  The inner (third) seal is often a pre-compressed impregnated foam strip.  This has to be be applied from the inside face, but not if panels have insulation with taped joints, or access problems such as against a shear wall or with structure behind.  In practice, a properly applied double ‘mastic’ seal will be 100% impervious and an inner seal is superfluous.

The above details refer to ‘plain’ concrete panels.  Where stone or brick facing is used, other details are needed.  In particular, it is important that (at least) the inner seal is applied between two concrete faces.  If this is not done then moisture may penetrate through fissures and imperfections, in the facing material, bypassing the seals.