Beam & Block
Installation

Foundation walls must be accurately constructed so that the beam bearing ends are well supported on the inner leaf but do not overhang into the cavity.

On ground floors a continuous damp-proof course must be laid along the top of the support wall, before the beams are lifted into position. To ensure a clean bearing on the support wall and to avoid damage to the DPC, the underside of the beams should be cleaned of dirt or debris before they are placed in position.

As the beams are positioned, infill blocks are laid between the ends to ensure correct spacing. The flanges on the beams should be cleaned of debris so that the blocks sit properly and beams should be 'tightened up' as they are laid, to minimise gaps between blocks and beams.

Once all the beams are in place, they should then be infilled with blocks over the whole floor area. It is important that blocks are not cut or drilled in such a way as to impair their performance.

The whole floor area must be grouted with a 3:1 sand/cement mix (using coarse sand) as soon as possible after the fixing of the beams and blocks has been completed. This should be done by brushing the grout over the floor with a stiff broom after the surface has been well 'wetted' so that the grout penetrates into the joints and provides a monolithic construction.

Walls running parallel with the beams are usually required to support a row of blocks and bearing levels should be prepared accordingly. Rackham's standard sections show this arrangement and it is advisable to study these before fixing commences.

Partitions can be built off the floor providing these have been allowed for in the design and are shown on the layout drawings supplied by Rackham's. It is sometimes necessary to place either two or three beams together to carry the additional load and in such cases care should be taken that the partitions are built directly over these units which must be concreted solidly together.

On upper floors, ceiling clips can be supplied to provide a fixing for timber battens. It is recommended that the clips be staggered on plan and lined up prior to grouting. The clip is placed on the shoulder of the beam and held in position by the infill block. The batten is placed between the two prongs, which are then bent around the batten and fixed with suitable nails, thus securing the batten firmly in place. Perimeter battens can be secured directly onto adjacent walls.

Beams must not be drilled or shot fired into under any circumstances.

During construction care should be taken to avoid overloading the floor. The following guidelines should be observed:

• Planks should be laid across the beams before stacking materials on top.

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• Stacked materials should be positioned as near to the floor bearings as possible.

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• Stacks of bricks, blocks or similar materials should be restricted to a total weight of 350kg (eg. 120 bricks or 20 blocks on each beam).

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Finishes

All normal finishes can be applied to Rackham floors, including screed and chipboard & polystyrene.

Screed should be a minimum of 50mm thick and in domestic garage floors the concrete topping should be reinforced with A98 steel mesh.

Full details of suitable finishes are available on request.

Incorporation of Services

Services must not be attached to the beams or blocks in such a way as to impact their strength or durability.

Soil pipes passing vertically through the floor can be accommodated by the removal of the infill block making good around the pipes with in-situ concrete.

In situations where landfill gas (methane) or radon precautions are required, services should not pass through the floor if at all possible. Where this is unavoidable the gas proof barrier should be carefully sealed around all penetrating service pipes. Water pipes must be pre-lagged.

If you require any more information please contact our Technical Department
on 01924 455876.