dampproof course

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damp course, damp check, dampproof course

In masonry, an impervious horizontal layer of material (as tile, dense limestone, metal, etc.) to prevent the capillary entrance of moisture from the ground or a lower course, but used also below copings, above roof level in chimneys, and elsewhere to stop downward seepage.
References in periodicals archive ?
So if it is not a broken dampproof course causing the dampness to rise, then what else could it be?
High abutting external ground levels This is where there is damp either at or above the line of the original dampproof course or at or above the level of the internal floor.
The construction of these in pre-Edwardian buildings are unlikely to have a physical horizontal dampproof course in the support walls below floor level, called the fender walls, these can "wick up", or draw up dampness from the ground below floors and introduce dampness on the walls of the chimney breast and reveal walls.
It may be surprising that all of the above are exclusions under a long-term dampness guarantee for rising damp and yet they are the most commonly-found causes, none of which require a retro-fit chemical dampproof course injection to solve them.
The only thing they may offer is a retro-fit chemical dampproof course injection and, of course, that peace-of-mind guarantee.
Secondly make sure there is a sound dampproof course beneath every bit of timber beneath the floor, not just the floor joists but also the timber bearers that carry the joists on top of the brick supporting walls.
The construction must be suitably robust, following Building Regulation guidelines and incorporate wall ties, lintels, dampproof courses and adequate sound insulation adjacent to a boundary with an adjoining property.