Smaller Brick Structures

Brick structures above ground can be built as walls, columns, arches and vaults. Arches and vaults are used in roof construction, and arches of brickare the most common way of spanning an openingfor windows and doors without having to usesteel reinforcement. The following rules of thumb should be used when building a complete wall without reinforcement:

• The building should not be higher than two storeys.

• The largest distance from centre-to-centre of structural walls should not exceed 5.5 m; the distance between bracing partition walls should not be more than 45 m.

Old bricks can be cut into tiles with thickness approx. 1,6 cm and used as flooring. Source: Stavne gard.

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Old bricks can be cut into tiles with thickness approx. 1,6 cm and used as flooring. Source: Stavne gard.

• Main loadbearing walls should be at least 20 cm thick, i.e. two bricks wide.

Alternatively, they can be one brick thick in lengths of a couple of metres between

30 x 30 cm buttressing columns.

• Window and dooropenings should asfaras possible be above one another.

Both solid and cavity walls can be built. Solid walls are straightforward to build, and can be insulated either inside oroutside, e.g. with wood-wool slabs which can be plastered or rendered. If the insulation is on the outside the brick's capacity to store heat is better utilized. Internal insulation means the walls will be cold towards the outside, increasing the riskoffrost damage.

Cavity walls are normally two leaves of single brickwork with a distance between them of 50 to 75 mm. A hard fired brick that will withstand frost is necessary in the outer leaf. Extra hard-fired bricks that are highly vitrified have a low capacity for water absorption and should therefore be ventilated behind. If the outside surface is to be rendered, bricks fired at lower temperatures can be used.

The inner leaf can be made of middle or low-fired bricks. Low-fired and porous bricks must be soaked before laying so that they do not absorb much moisture from the mortar. Low-fired brick binds well with clayey binders such as hydraulic lime, but less well with pure limeproducts (seeTable17.1).

The leaves are usually bonded together with simple steel ties. In cold climates, the cavity is usually filled with insulation, preferably of mineral origin, such as perlite, ver-miculite, expanded clay clinker or granulated and expanded waste glass. In areas wherethere is heavy driving rain, it pays to render the inside ofthe outer leaf too. Beams resting on the inner leaf should be surrounded with impregnated building paper to avoid humidity damage. Birch bark is also an option.

Avapour-tight render or paint should be avoided on the outside, since it will quickly result in frost damage. Good alternatives are hydraulic lime render and silicate paints.

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