Tips to Prepare Your Concrete Subflooring for New Flooring Installation

Sep 30 2020
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Preparing concrete subflooring (especially an OLD concrete subfloor) is not always for the faint of heart. Depending on what was on it to begin with etc. It can require some serious manual labor. We’ve just tackled our basement floors and let me tell you: 100 year old concrete requires some serious time. It will all be worth it in the end though, new flooring can majorly improve a space for not a lot of money!

How we completed our Basement Epoxy floors using Rustoleum's RockSolid flooring Kit - after a thorough cleaning, scrubbing and acid wash Lodi(This is a contributed post, for more information about my compensation please read my disclosure policy)

Are you ready to install new flooring in your home? If so, the success of the project is dependent on how well you prepare the subflooring before putting the new material down. Keep reading to learn how to prepare your concrete subfloor from removing the existing flooring to using a concrete floor scraper and finally installing the new flooring material.

Measuring the Space

Before doing anything, it is a good idea to carefully measure the space where the new floor is being installed. This is going to let you know the amount of new flooring material you need to purchase.

To figure out this number, multiply the length by the width of the room. It is smart to add about 10% to that amount to account for any issues, mistakes, or other unforeseen problems.

Now, it is time for you to remove the old flooring and start preparing your concrete subflooring. If you are dealing with a vinyl floor, you may be able to install the new flooring over it, but this is not always the case. Make sure you read the manufacturer’s instructions to know for sure. Remove all the baseboards in the room to ensure there is the proper gap space at the edges of the floor.

Getting the Subfloor Ready for New Flooring

Preparing the subflooring is a multi-step process. To ensure your flooring is installed correctly, follow the steps here.

Clean the Surface

If you are using flooring that includes an adhesive, you must clean the subfloor or the old flooring in place from any adhesives, sealers, paint, wax, oil, and other dirt and debris. You need to make sure the surface is not slick, burnished, or too heavily troweled.

If it is necessary, you can use a concrete grinder or scraper to remove the coating present. This will also help to roughen the surface of the concrete to ensure the adhesive material will stick. If you plan to install a floating or locking floor that is not attached to the subfloor, be sure the subfloor is clean.  

Level the Subflooring

To see if the floor is level, you can use a tape measurer and a long level. Usually, the floor should be uniform and level within about 3/16th inch for every 10 feet. Be sure to check the new flooring’s manufacturer’s recommendations to see if this is the right measurement.

If you find high spots, you can sand them down using a concrete grinder. If there are low spots, using a cementitious leveling compound will help you level them out.

Dry the Subflooring

Before installing new flooring, you need to ensure there is no moisture present that may cause damage or other issues. You can do this using a moisture test kit. If the moisture levels do not meet the new flooring’s manufacturer’s recommendations, it is necessary to reduce the humidity levels in the room or area.

Ensure the Subflooring Is Structurally Sound

You need to make sure the concrete subfloor is strong enough to support the new flooring being installed, along with the furniture and the people who will be using the room. Be sure to check for any signs of crumbling or cracks, which indicate a problem.

Installing the New Flooring

Once you have thoroughly inspected and prepared the concrete subflooring, you are ready to move on to the next step, installing your new flooring. Be sure to follow the manufacturer’s instructions to ensure you achieve the desired results. While flooring installation may take some time, it is usually well worth it in the end. Being informed and knowing what to do will help ensure you achieve the desired results. 

Preparing concrete subflooring (especially an OLD concrete subfloor) is not always for the faint of heart. Depending on what was on it to begin with etc.
(This is a contributed post, for more information about my compensation please read my disclosure policy)

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