The best solution for basement floors and finished basements are decorative concrete overlays with area rugs.
Here is why.
Moisture - Below grade space will have moisture. Moisture will come from numerous sources. Gutters work great but few people bother to maintain them. In time they pull away from walls, debris gets in them, downspouts dont provide proper runoff. The result, rain water runs down along the foundation wall and frequently below the concrete floor. The water pressure pushes through concrete which is porous. Dry air in the basement helps pull moisture through the slab. So you have moisture, at least a little.
If you re on a slope rain water will run towards the house. Underground springs are another source.
2. Height - Basement floors are seldom a consideration when designed. As a result doorways and stairs are a problem. Code requires six inch risers at stairways. If you put down any flooring that raises the floor height so last step to floor is less than code requirement you can have a problem when selling your home. I see this frequently even in Multi-million dollar homes. Recently a builder friend of mine had built a 12,000 square foot spec home he was going to put on the market for $6.5 million. The building inspector happened to look at the basement floor and said "what are your plans for the floor?" Then he pulled out his tape measure. Any flooring more than 1/8th inch thick and the builder would have been denied his Certificate of Occupancy.
I might add, even if there wasnt a code issue all the doors would have to be cut down if any flooring added height, like tile or hardwood.
The solution- First either stained concrete or a concrete overlay will solve height and moisture issues. What I do advise to determine the extent of moisture is to tape down squares of plastic wrap to your concrete floor. Use duct tape and tape plastic around all edges so air cannot get out. Leave for 60-72 hours. If you see moisture on the plastic you will likely need to apply an epoxy waterproofer to floor first. This works as a topical moisture vapor barrier preventing moisture from wicking through concrete.
If moisture doesnt appear on the plastic it doesn't mean you don't have moisture. You can also turn on your dehumidifier. Moisture will fluctuate depending on the time of year. The moisture that collects in your dehumidifier is the same moisture that ends up in carpets.
Providing that you get your basement moisture under control the application of a decorative concrete overlay is the best solution. Overlays are breathable and will allow moisture vapor to pass through. They are easy to install and very inexpensive. Typical installations are 2-3 days and less than $2.00 per square foot. (if concrete floor is blemish free you can stain concrete and seal it for about 50 cents per square foot) Once the decorative concrete overlay (or stain) has been applied area rugs can be put down. The beauty of the area rugs is that they can be removed for cleaning or replaced. This solves the problem of unhealthy mold, mildew and resulting poor air quality caused by moist carpets.
Do it yourself floor staining and overlays are the perfect solution for finished basements. Before jumping into a remodel research basement flooring ideas before starting. The right solution will save you lots of money and you ll use your space frequently.