Thinking I was going to lay carpet, I mistakenly painted a concrete subfloor to keep the dust to a minimum. Now we decided to lay tile in front of my french doors. Is there an easy fix without scraping off the paint? Can wonerboard or durock be adhered over the concrete floor prior to tiling? If so, is either a better option (durock or wonderboard)?

Just install cement board over paint.

All could work here in boards. Durock can be used out side.

DUROCK® Cement Board - USG Corporation (http://www.usg.com/navigate.do?resource=/USG_Marketing_Content/usg.com/web_files/products/prod_details/DUROCK_Brand_Cement_Board.htm)

Just install cement board over paint.

All could work here in boards. Durock can be used out side.

DUROCK® Cement Board - USG Corporation (http://www.usg.com/navigate.do?resource=/USG_Marketing_Content/usg.com/web_files/products/prod_details/DUROCK_Brand_Cement_Board.htm)

What type of adhesive should I use?

This is a good adhesive made for this application.

Recommended For:
Bonding building materials (concrete, lumber, etc.) to subfloors, tileboard, treated lumber, cabinets, foamboard, countertops, granite, marble, drywall, ceramics, mirrors, plastic, vinyl, 1/8" MDF paneling, brick veneers, plywood and waferboard.

Liquid Nails® - Polyurethane Construction Adhesive (low-VOC) (LN-950) (http://www.liquidnails.com/products/product.jsp?productId=54)