Why Put Paper Under Wood Floors?

Some floor-installing practices have been around for so long that people forget the real reason why it started, veteran construction science engineer Foster Lyons says.

For instance, it remains common to put rosin, felt, or some other type of paper between wood flooring and the subfloor. While people might give you several reasons why, the truth is that it was first used in the 1800s to reduce air flow through floor assemblies.

Is it needed today? Well, what matters more is having a good vapor barrier when you’re laying flooring over concrete or in a crawl space, Lyons says. Paper is a poor substitute, and you shouldn’t be trying to control water vapor transfer between sub flooring and finish flooring in any case. Read more >