Step by Step Subfloor Preparation for Flooring

Before beginning the process of installation or even buying material, some measurements need to be taken to ensure no issues in the process later on. If these measurements won’t be accounted for in the beginning, they’ll waste more time later on. Every contractor or DYI floor installer will begin preparing the subfloor by calculating square footage, removing the old, polishing, measuring, and finally installing.

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Calculate

First, calculate the room’s square footage by multiplying its length by its width. It is easier to split the room(s) into smaller squares or rectangles if they are shaped irregularly. Add 10-12% to the total to account for any mistakes or warped boards.

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Remove the old

Pull out the old floor or carpet with the necessary tools (hammer, scraper, grinder, Dremel, etc.) Using a prybar and a hammer, remove all baseboards to create an expansion gap. Expansion gaps are necessary for all flooring types to allow new flooring to expand from moisture and heat. Check clearance at door casings. The underlayment and plank need to fit. If they don’t fit, use a Dremel or an undercut saw with the proper safety to cut to the right size. A lot of these tools can be found or rented at your local Home Depot or Lowes.

Requirements

Before installation, every subfloor has to meet the requirements: clean of any dust, completely level, and dry.

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Clean

Before beginning prepping the floor, the floor must be clean. It must be clean of paint, sealers, wax, any blemish that will create bumps or uneasiness to the new flooring. Use a scraper to scrape any paint along the ends of the room and especially at areas between door frames. The subfloor needs to be polished using a concrete grinder to remove any coating and create the conditions necessary to be level.

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Level

Using an 8-10ft level, mark any low or areas that contain hills or high spots. The floor must be level and uniform within 3/16 in every 10 ft. It is important to check the manufacturer’s recommendations for any additional information. If you come across high spots, grind them down with a concrete grinder until specifications are met. Fill any low spots with a self-leveling compound used for concrete fillings and use the level to spread if necessary. Before proceeding, make sure that the compound dries and is polished with a grinder.

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Dry

Every manufacturer has different specifications. Check the specifications for moisture and test the moisture level with a moisture test kit. This also includes temperature levels. The material must accustom to the room in a period of 72 hrs before installation. This will reduce issues with warping and rapid expansion.