Hardwood flooring and wood flooring planks are generally sturdy floor covers, but if you install wood floors on uneven surfaces, it is possible that wood flooring planks will bend or crack when weight is applied to them. If you have an uneven surface in your home where you want to install wood flooring, you must take the time to level the floor and create an even surface on which to install your new flooring surface.
Find all of the problem areas in your floor. To find uneven spots, lay a flat metal ruler or a sturdy wood board against the floor in a corner of the room. Move across the floor and look under the board. Mark any low spots in the subfloor surface.
Fill in the low spots in the floor to make the floor's surface even. Mix levelling compound or wood filler in a bucket, according to the directions on the packaging, and apply the compound to the low spots in the subfloor with a putty knife. After filling each low spot, run the edge of the putty knife across the spot to remove excess compound, and wipe up any compound left around the low spot with a wet rag.
Let the compound dry for 24 hours, and then recheck the floor with the ruler or board where you filled the low spots. Sand down any of the spots that are higher than the floor's surface with sandpaper.
Clean the floor to remove the sanding dust and any dirt from the floor. Use a damp mop or rag to clean, unless the floor has greasy spots. If the floor has greasy spots, mop with a grease-cutting cleaner to remove the oily areas and rinse with clear water.
Put down a waterproof underlay in rooms , such as kitchens, where spills may pose a problem. Make sure you follow the manufacturer's instructions for your specific underlay, but, generally speaking, you install an underlay by smoothing it out across the floor and using the recommended adhesive to apply it.
Install the wood floors over the levelled surface. Follow the instructions provided by the manufacturer to install your wood floors correctly.