Ceramic Tile on Particleboard Subfloor

[iabteri]

Hello:

I was getting ready to install 1/2" Hardibacker 500 and 20" ceramic tiles in the office of a new manufactured house. While looking up installation information on the web I realized that the particleboard (ANSI A208.1.99) used as the subfloor is not adequate for ceramic tiles. Some say it will be okay with the backerboard, some say not in any instance should they be put on this type of subfloor and the particleboard should be removed and replaced with plywood. I was surprised when I read this because the particleboard seems very solid. In addition the thinset I purchased says do not use on particleboard. I am in the high desert so it is very dry here. According to the Chamption rep.(this is a Redman MH) under the particleboard are the floor joist and insulation (and some sort of plastic barrier is under the house), so replacing the particleboard would not be something I want to tackle. If I can put the backerboard on the particleboard what do I use to attach it? I really wanted tile but do I need to return everything and do something else?

This is what happens when you take action and then investigate afterwards!

Any advice would be appreciated.

Teri

[David Oxhandler]

I think I would put a quarter inch plywood layer over the particle board prior to installing the backer board.... talk to the producer opf the tiles and ask for their recomendations.

[BILLY]

I will try to be of help here as I am a Lowes employee with 2 years in the flooring dept. First off the 1/2" backer board you have purchased is really intended as a replacement for drywall in the tub/shower area. Typically 1/4" backer board is used on wood or particle board floors. Normally over a plywood or solid wood floor you would put down a layer of mortar ( a high latex modified, such as Ultraflex 2 would be put down first then the backer board then another layer of Ultraflex 2, and then lay your tiles down. However as you have a particle board floor, do not put down that first layer. Instead fastner the backer board directly to the particle board using Hardi backer screw that are sold in the same area as the backer board is sold at Lowes. As the Ultraflex mortar is mixed with water, you definately do not want to put this down on the particle board. The reason for using a mortar such as Ultraflex 2 is that it is designed to absorb flexing or movement of a wood subfloor over which ceramic or porcelain tile is laid. Use the wrong or a cheap type of mortar and you will have cracked tile in a very short amount of time. Also follow the directions of installing the backer board using the proper fastners( no, drywall screws will not work,they'll snap off at the head). Yes, the proper fastners are expensive and you do need to put about 48 of them per 3' X 5' sheet of backer board. but if you do this installation correctly you will have a beautiful and long lasting tiled floor. Another possible option would be to put roofing felt down over the particle board floor then fasten the backer board over it. Putting down a plastic sheeting vapor barrier won't be of much help as the 48 holes, per sheet, from the fastners will allow moisture to wick down the screw shafts and cause problems with the particle board. good luck with your project, And feel free to call your local Lowes and speak with a flooring specialist. They will be glad to help you with your project.

[iabteri]

Thank you very much for the replies. I returned everything and repurchased the items you suggested, Billy. I like the idea of the roofing felt so I also purchased that, also. I'll start the project this weekend. Thanks again. Teri