What is rising masonry (superstructure brickwork)?
Rising masonry — in Dutch opgaand metselwerk — is the brickwork that rises from the foundation: the walling above ground level, as distinct from the foundation masonry beneath it.
In specifications and cost plans this distinction matters, because very different demands are placed on the two parts. Below ground the masonry works in a permanently damp and often aggressive environment; above ground it is about weather resistance, frost resistance and the appearance of the façade.
Differences from the work below ground
- Type of unit — for the rising work you select a facing brick on colour, format and frost resistance. Below ground you use a unit that copes with moisture and salts: hard, low-absorption brick or concrete blocks.
- Mortar — for rising masonry, a mortar matched to the brick; below ground, a stronger and denser mortar.
- Damp-proofing — at the transition sits the horizontal damp-proof course, which stops rising damp from the foundation. This is the most critical detail of the whole junction.
- Pointing — the rising work is pointed or struck; below ground that is unnecessary.
Practical points
- Start the rising work deliberately at the right height. Keep sufficient distance between ground level and the first course of facing brick — if the ground is later raised, or paving is laid too high, the damp-proof course is bridged and rising damp follows.
- Check that the damp-proof course is continuous into the cavity and turned up at the right height; a break in it is virtually impossible to repair afterwards.
- Open perpends in the bottom course of the outer leaf drain cavity water and ventilate the cavity.
- Keep the cavity base clean. Mortar droppings on the wall ties and at the base form bridges along which moisture travels inward.
- Build in suitable weather. New masonry is vulnerable to frost and to being washed out by rain; keep it covered.
Related terms
- Bricklaying
- Cavity wall
- Ground level
- Facing brick
- Damp-proof course
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