When: Apply concrete floor sealer before use of the concrete floor. Whether you will be leaving the floor bare, painting it, installing carpet, hardwood, etc. a sealer needs to be applied. As long as the concrete has had a month to cure (a month since it was poured new), then it’s time to seal it.
Why: Concrete is porous. This means it is full of tiny little holes. Think of these holes as a maze where moisture can creep in. Sure it’s not a lot of moisture, but on a hot and humid summer day, you don’t want that moisture in your house. Humidity makes you feel warmer therefore causes you to turn up the air conditioner and costing you money.
If your house usually seems worse then it is outside (hotter in the house then outside in the summer, and vice versa in the winter) an unsealed concrete floor could be a contributing factor. Think of concrete floor sealer as another form of insulation. Another bad thing about moisture coming in through the concrete floor is that it can make carpet damp and smelly. It can also wreak havoc on hardwood floors with all the added expanding and contracting caused by the unnecessary moisture.
The worst place for moisture to seep through a concrete floor is a basement. This can lead to actual puddles of water rather then just a little humidity. In a basement you may want to seal not only the floor, but also any concrete walls you have.
More reason why to use a concrete sealer is that it will repel spills preventing stains. This is especially important if you will be leaving your concrete floor bare such as a laundry room or a garage. Once a stain sets into concrete you pretty much can never get it out, so thinking ahead could save the aesthetic appeal of your floor. If you will be painting your concrete floor, a sealer can act as both a sealer and a primer in one step. It will also keep your paint finish longer because of the moisture it blocks from both the ground and from the surface.
How: First you need to prepare the concrete floor. If it’s a bare floor then mopping it with soap and water will do. If it’s a high traffic area then it may need a really good scrubbing. If it is carpeted or has another flooring on it, you will have to completely remove the flooring to get to the concrete. Most likely this will leave holes, dents, and cracks on the floor. You can fill those in with a concrete crack filler, usually looks like caulk but it specifically says “concrete filler.” Let dry according to directions before applying a concrete sealer.
There are at least a few different kinds of concrete floor sealers (water based, epoxy, etc.). If you aren’t sure what kind of concrete floor sealer is best for you, consult with someone who works at your local home improvement store.
They will at the very least show you where the sealers are. If they are trained they will help you decide which sealer is right for you. If they aren’t very useful then just read the packaging and compare information such as clean up, drying time, and application method recommended. Pick the one that will be the easiest for you.
Most concrete floor sealers can be applied as easily as paint. Poor into the paint tray, load your roller, and paint the floor. Just be sure not to paint yourself into a corner.
Another option is to use a mop and a bucket. Since sealer isn’t as thick as paint this can work. Be consistent with your mop strokes the same way you would be with a roller. Either tool you choose your goal is to get an even, smooth finish over the entire floor surface.