This is the big question, right? You know the types; you can weigh the pros and cons…kind of. What you really need to know about underlayment is which option is the best choice for you. Don’t worry; we’re not gonna leave you hanging.
For carpet, you will almost always use a foam or rubber carpet pad. These pads come in many different thickness options ranging in properties and pricing. Thicker pads will (typically) make your floor softer and more comfortable to walk on.
Make sure to pay attention to the properties of the carpet pad you’re looking at, not just the price and thickness. While you can find some thicker options at lower price points, they make not do all the things you want them to do (like absorb sound), or at least they might not do them very well.
Make sure to check out those specs!
For tile flooring where a thinset is used, the best solution is a rubber-cork underlay. You can also install ceramic tiles directly over plywood or a cement board.
Thinset mortar sticks well to cork, wood, and cement but not much else.
Hardwood, Engineered Wood, Laminate & Vinyl
When installing hardwood, laminate, or engineered wood flooring, the best underlay options are foam and cork.
However, foam does have more give than cork so, while it is the more popular option, we recommend cork. Cork has less give, making it less likely to flex underneath your planks. There are some extra dense grades of foam that can work under wood floors, but they are usually not as durable as cork.