Concrete Floors Liverpool

A rotten or damaged suspended timber floor, on the groundfloor of a house, can usually be replaced with a solid concrete floor if you wish. However, you should always check with your local building control officer as this can effect the ventilation properties of the house. Additional insulation and waterproofing may also be required, so investigate carefully before going ahead.

Preparation

Your first task is to remove the existing suspended floorboards and joists. Remove all of the boards first and then saw through the joists and pull them out of the wall. It is also a good idea to remove the door and the skirting boards as these can get in the way later. Fill the holes left by the joists with trimmed bricks and mortar and allow the mortar to dry. It is then a good idea to treat the subfloor and walls below ground level with a strong chemical fungicide solution.

Materials Needed:

Sand

Cement

Aggregate

Infill Material (e.g. brick or tile rubble)

Polythene Damp-proof Membrane

Polystyrene Insulation Boards

Bonding Agent

Mark the wall with a levelled chalk line to indicate the finished floor level required. This should take into account the thickness of any floor covering you plan to use, such as tiles or wood blocks. Measure down 50mm and make another chalk mark to indicate the layer of screed, taking the mark all the way around the room. A third mark 100mm further down the wall will show you the thickness of the concrete slab required. A final mark 50mm below that will give you the position of the insulation board you will usually need to install. Anything below this final line can be filled with infill material.

Infill

For the infill, you should plan to use tile or brick rubble, or gravel rejects (coarse stones from quarry waste). Lay this down in layers of no more than 200mm before compacting it down and breaking up larger pieces with a sledgehammer. Be sure to pick any wood or metal out of the infill material as this can effect the concrete when it is laid. Continue to add layers of compacted infill until you reach a level about 25mm below your lowest chalk line. Fill this last 25mm with a layer of sand, which should then be tamped flat.

Damp Proof Membrane

Choose a 1000 or 1200 gauge damp-proof membrane and lay this carefully over the bed of sand. The edges need to be run up the wall to above the height of the finished floor level to form a tray. Fold the corners neatly and hold in place with paperclips or staples. If your sheet of DPM is not large enough to cover the whole room in one, you will need to join two pieces together. Overlap by at least 200mm and seal the join with waterproof tape.

Insulation

Lay polystyrene insulations boards on top of the DPM, making sure that they are fitted closely together and the joints are sealed with duct tape (or another strong type of tape). Take care to fit the insulation boards tightly against the walls and not to leave any gaps. Polystyrene insulation boards...