Do I need a moisture barrier under hardwood floors?
Subsequently, one may also ask, do I need an underlayment for hardwood floors?
The short answer: usually. If you already have a plywood subfloor, and the subfloor is smooth and level, then you may not need an underlayment beneath the hardwood floor. Plywood has some moisture resistance already compared to solid wood, and it mostly gives a smooth surface.
One may also ask, do you have to put a moisture barrier under laminate flooring?
Sometimes the underlayment is already attached for you, but you may hear the term moisture or vapor barrier when installing laminate flooring. You will need a moisture barrier underlayment when installing: On a cement subfloor. On any subfloor that has a chance of moisture coming up and soaking into the flooring.
When installing hardwood or engineered wood flooring, the best underlay options are cork and foam. However, foam does have more give than cork so, while it is the more popular option, we recommend cork.