In most cases, you do not need to put padding or underlayment under carpet tiles. Unlike traditional carpet, which requires a separate pad, carpet tiles are designed to be installed directly onto a firm subfloor like plywood, concrete, or tile. Many carpet tiles come with a built-in underlay and attach with peel-and-stick adhesive, double-sided carpet tape, or glue. For a more comfortable, cushioned feel, especially in residential settings, you can opt for padded carpet tiles that have a thicker underlay attached. While it's generally not recommended to install a separate pad, a compact underlayment might be used in some situations, though this typically requires professional installation. An acoustic underlay may also be considered in commercial spaces or multi-level homes where noise reduction is a priority.

There are a few different types of finishes to choose from for the final step of the project. 

Water-based polyurethane sealants emit fewer odors and fumes but dry quickly, which can pose a challenge when trying to get a smooth coat. Oil-based polyurethane sealants let out more odors and fumes into the air (it’s especially important to wear a respirator if you choose this type), but they take longer to dry, which can be more forgiving during the finishing step. 

Some may prefer wood oil to polyurethane because rather than creating a layer, it becomes part of the wood. Wood oil takes longer to dry, and is less resistant to wear and tear; however, it creates a natural-looking result by enhancing the grain of the wood. 

While many hardwood floors can last decades with proper maintenance, choosing a harder wood type, like hickory, can help extend the life span of your hardwood floors and reduce the amount of maintenance needed to keep them looking new and shiny. Softer hardwoods, like walnut, may not last quite as long as other types.

The difference between a 40-oz. and 60-oz. carpet is the carpet face weight, meaning the 60-oz. carpet weighs 20 ounces more per square yard. When looking at two similar carpets of the same material and type, the 60-oz. carpet face weight likely indicates higher quality and more durability due to heavier carpet fibers.