How to Install a Concrete Floor

Laying an interior concrete floor is usually a renovation project that takes place in your basement. Learn how to remove an old wood floor, prepare a base and pour a concrete floor.

Excerpted from Do It Yourself Home Improvement

Highlights:

Prep and Excavate
Lay Insulation Board
Pour Concrete

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.

View photo gallery instructions for this project

Prep and Excavate

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).

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Excavate Ground to Required Depth to Pour Concrete

Fill with Crushed Stone and Ram Until Compact

Cover Stone with Sand and Smooth with Shovel

Lay Sheet Plastic on Sand and Tape in Place

Lay Insulation Board

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.

Put Insulation Foam Board Across Sand and Plastic

Pour 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.