More in Floors
It is possible to pour the concrete and level it off by eye, but it is far more accurate to use a screed board. Here, insulation is used as screed and as a leveling guide. However, you could use wood offcuts to make a temporary frame around the floor edge, which you would remove after use.
Remove the baseboards by prying them away from the wall using a pry bar (Image 1).
Use a pry bar to remove the floorboards one by one (Image 2). Once the floor is out, mark the required height of the floor with a chalk line.
Excavate to the required depth (Image 3). Snap chalk lines to indicate infill layer levels.
Fill to the height of the appropriate marked-off level, with crushed stone. Compact with a rammer (Image 4).
Cover the stone with sand, up to the height of the next guide line. Move the back of a shovel in a circular motion, to smooth the sand (Image 5).
Lay the 6-mil sheet plastic on the sand. Take it up the wall above the finished floor level. Tape it to the wall to hold it in place (Image 6).
Place the insulation foam board across the sand and membrane, cutting sections to fit as required. Cut 4-inch widths of insulation board and lay them around the edges of the room. The insulation provides a guide for the height of the concrete pad, as well as a rest for a leveling plank as you lay the concrete.
Shovel the concrete over the floor, starting at the wall farthest from the door (Image 1).
Scrape a straight-edged plank across the concrete to level it, using the top edge of the insulation as a guide (Image 2).
Fill in any gaps or indentations using a trowel as you work backward. You may need to go over the area more than once (Image 3).
Use a plastering trowel to smooth any rough areas, right to the edges of the insulation foam. Leave the concrete to set for two to three days (Image 4).
Place furring strips on the dry concrete. Apply a top layer, leveling it to the top of the furring strips (Image 5). Remove the furring strips and fill the gaps.
Level the surface using a float (Image 6). Work to the edges and back toward the door. Leave for another two to three days to set completely.
Excerpted from Do It Yourself Home Improvement
© Dorling Kindersley Limited 2009