You’ll usually need to prime a garage floor before painting—especially if the floor is unpainted. Garage floors are made from concrete, which is porous and produces dust. The dust can contaminate the paint and cause issues with adherence. 

Primer creates a barrier and gives you a clean surface to work on. It also minimizes absorption to help give you an even, pro-looking paint job. Make sure you choose a primer that’s specifically designed to cover concrete flooring.

Polished concrete floors also have downsides. Some homeowners, for example, might dislike the coldness of the material (though area rugs can help warm up the space). Concrete floors are also hard, which isn’t always ideal for children and pets. What’s more, these floors are susceptible to cracking, and repairs can be costly. Some homeowners might not like that installation isn’t DIY-friendly. 

It costs between $600 and $8,400 to stain an average-size concrete patio of around 300 square feet. The wide price range accounts for intricate stains that incorporate multiple colors and stenciling, high-end sealers, and special touches, such as stamping or concrete polishing. Prices can also vary if you need to make multiple repairs to your patio before adding the stain and seal.

It typically takes 1-2 days to coat a concrete floor, including preparation and curing time.