What do you do when you are trying to tile over a wood subfloor that has areas that don't meet flatness requirements? Patching materials are used to flatten a substrate, making it allowable to install tile over. In this module, you will learn about when and where patching materials can be used over wood substrates. To complete this course and receive a certificate, you will need to complete the online module which will take a minimum of 7 minutes and then you will be required to take a 9 question quiz about what you just learned.