Painting Basement Floors

Painted Basement Floor
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Most unfinished basements have a concrete floor/subfloor that is the upper surface of the foundation block that the building rests on. In its raw state, this material can be rough, coarse, and unsightly. The simple application of a coat of paint can be a quick, easy, and cost-effective way to elevate this subterranean element and through it the surrounding environment.

The Basics

You will need an epoxy paint that is specially formulated for use on concrete surfaces located in below-grade spaces. These products are manufactured to withstand the natural expansion and contraction of the floor due to fluctuations in temperature throughout the year. They will also be able to handle the heavy weight of vehicles, machinery, and stock products as well as high foot traffic situations.

The other advantage of employing a quality concrete epoxy in a basement is that it can help to waterproof the floor. When applied, the paint will spread over the entire surface and then dry, creating a tight membrane that will not allow water to pass through it into the concrete below, except under severe flooding conditions.

Preparing the Basement

  • Temperature: You want to ensure that the temperature in the room is between 50 and 90 F. That will allow for optimal drying of the epoxy used. If the basement is too cold, space heaters can be employed though you need to use caution and never point the flow of heat directly at the paint as it is flammable and this can constitute a fire hazard.
  • Repairs: If there are any cracks in the concrete, they should be filled in using a repair compound or concrete patch product. Likewise, if there are any raised surfaces, those should be sanded or ground down. Otherwise, they will visually blend into the painted palette and become insidious hazards for tripping and poking.
  • Flooding: You need to take all of the standard steps required to prevent flooding in the basement as standing water can ruin a paint job. This includes sloping the ground soil away from the structure of the building, ensuring that the gutters are clear and pointed away from the walls, and making sure that it is in good working order if a sub pump is available.
  • Humidity: Since they are situated below ground level, basements often have high levels of humidity. If there is too much moisture in the air, it can slow the rate at which the paint dries, or cause it to set incorrectly. In those situations, a dehumidifier can do a lot to help the problem.
  • Dirt: Sweep or vacuum the surface of the floor thoroughly. You want to make sure that there is no loose dirt or debris that will get caught permanently under the drying paint.
  • Mopping: This is optional, but it can help to get the floor completely clean before you apply the paint. Only damp wash the surface, and afterward use clean water to remove any trace of soap. Then towel up any wet spots that remain; you don’t want liquids lingering after you are done. You will have to wait a full 24 hours for the concrete to dry out. Afterward, it may be useful to test the material for excess moisture. Only when you are sure that the water has completely evaporated should you proceed.

Priming The Floor

Primer needs to be applied before the paint so that the epoxy has the optimal surface to bond with. This can be poured into a paint tray and applied with a roller brush attached to a long handle. Start at the wall farthest from the door, and work your way back towards the exit so that you don’t paint yourself into a corner. Use long strokes as you go and try to apply it evenly over the entire area. If bubbles or puddles form, roll over them with a mostly dry roller to smooth out the features. When you are finished you need to wait a full 24 hours for the primer to dry completely.

Important Note: Primers and paints often contain chemicals, so try to ventilate the basement as well as you can during the application process.

Painting the Floor

  1. Start by adhering painters tape to the walls everywhere that they touch the floor. This will keep the color from spreading to unwanted surfaces.
  2. Pour the paint into a tray, and then use a hand brush to apply it to the floor nearest where the walls are. A roller is more efficient, but it can be hard to get an even coat near the walls in the room. Applying it by hand to about 12 inches out can make the process much quicker and less frustrating.
  3. Once you've painted a perimeter, you can switch to a roller attached again to a long pole. For this process start at the wall farthest from the door once more and work back towards the opening to avoid having to step on wet paint. You want to make sure that the coat is as flat and seamless as possible with few if any impressions left behind by pins or bristles.
  4. When you’re finished, give it a good 12 to 24 hours to dry. Once that is done you can apply a second coat and after that a third, as long as you wait for that full 12 to 24 hours between each. Three to four coats is usually sufficient.