Using a self-levelling concrete compound on an uneven wooden subfloor provides an effective way to prepare for your new floor covering. All tile products benefit from installation on an even subfloor, which helps produce a quality finish that retains both durability and aesthetics. Self-levelling concrete requires both preparation and the correct application to create a successful result.
Sweep the wooden subfloor with a push broom to remove all loose debris. Clean up any traces of dirt from the wood using a degreaser and a damp cloth.
Check that all floor boards are firmly attach to the floor joists in order to reduce flex or bounce in the subfloor. Use flooring nails and a hammer to fasten the wooden boards at regular intervals. Commonly, fasten boards every 6 inches along floor joists to create a secure subfloor.
Read the self-levelling concrete compound directions to determine whether a second level of plywood is required to further reduce subfloor flexibility. Install the grade of plywood that the levelling compound manufacturer recommends.
Brush latex floor primer evenly over the wooden subfloor with a clean paint roller. Allow the primer to dry according to the manufacturer's directions. Usually, this will take about two hours.
Use a carpenter's level on the subfloor to determine where the wooden surface is uneven. Mark the uneven areas with a pen to quickly recognise where you need to pour the self-levelling compound.
Mix up the self-levelling concrete according to the manufacturer's instructions. Use a clean bucket and add the water first, before the dry powder. Mix the compound using an electric drill with a mixing paddle or hook attachment. The mixture should have a very wet, almost soup-like consistency.
Pour the self-levelling concrete mixture over the floor, following your marks. Wait approximately 2 minutes to allow the concrete to level. Feather the concrete edges out and over the adjacent wood using a trowel to create a smooth and even transition.
Allow the self-levelling concrete to completely cure before installing your final floor covering. Read the manufacturer's guidelines for the cure time, which can vary from hours to days between different products.
Fasten strips of wood on the floor at door openings to stop any levelling compound from crossing a room boundary. Choose self-levelling concrete compound with a high content of flexible polymers in order to avoid or reduce the need to install a plywood layer on the subfloor.
Wear a respirator and protective gloves while using self-levelling concrete to prevent injury from chemical contact. Work quickly with the concrete mixture to avoid the self-levelling compound from setting before you finish.