Hardi backerboard over luan

I am putting new travertine in my bathrooms upstairs and they both had lenoluim fooring before. I pulled up all the lenolium flooring and found luan underneath. The only problem now is the luan seems to be really stuck to the plywood flooring making it almost impossible or difficult to remove like the builder has glued it to the plywood. Can I not put the Hardi Backerboard on top of the luan and make this install ok? What are my options? I was going to glue the hardi backerboard to the luan and use 1 1/4 inch cement screws to secure it. Can someone give me some good advice on this? I do not want to have to remove the plywood.

Thanks,

dtaylor1119

Bad guess...luan is very soft and will swell up and create problems for your stone tile. Also, stone tile requires two layers of properly installed plywood (and luan doesn't apply!). Plus, a floor with stone requires it to be twice as stiff as one without for ceramic tile. Have you calculated your deflection specs?

Hardie along with pretty much all cbu's, either specs or highly recommends thatyou use thinset under it. The thinset is used to fill minor imperfections and provide 100% support for the floor.

Highly suggest you go over to www.johnbridge.com and get some advice on this, otherwise, you'll have an expensive failure.

100% Agree with Jim. Head over to JohnBridge.com.

Between his site and this site, you've got the two best resources on the Internet.

You must rip up that floor. You will need two layers of plywood. You will need Hardibacker put on with modified thinset. You will need to reinforce that floor to reach a minimum of a 720 L deflection.

Otherwise you'll have a very expensive and time-consuming failure on your hands.