I have a question about my installation. I'm sorry about the length but I'm thoroughly confused at this point. I have a 3/4" Advantech subfloor with I-Joists every 16". I have staple-up radiant under the subfloor using heat transfer plates. I was in the process of laying down 1/4" Hardibacker EZ Grid using Versabond Fortified Thin-Set Latex Mortar (polymer modified). [url]http://www.custombuildingproducts.com/ProductCatalog/SettingMaterials/LatexPortlandCementMortars/VersaBondFortifiedThinSet.aspx?user=arc&lang=en[/url] As to the thickness of the floor, I would have done more but I'm trying to keep the R-value down because of the staple-up radiant. It is a catch 22. I would like a stronger floor but it would reduce the efficiency of the radiant system. Otherwise, I would have done the 1/2" plywood with 1/4" hardibacker or a 1/4" multiply with 1/2" hardibacker. I am screwing it down but I can only use a 3/4" screw because of the staple-up radiant. I tested a 1" screw but it still pokes through so I couldn't risk it. Because of this, I am screwing on a 4" grid instead of the typical 8". I'm also using a standard wood screw instead of the backer screw since it's not available in a 3/4" length. I was even thinking about hitting it with an air stapler using 3/4" staples. One tile guy I talked to said I should be using an acrylic admix mortar to lay down the hardibacker instead of the latex mortar I'm currently using. He said I needed the better adhesion for the Advantech. I was under the impression that the layer of thinset beneath the hardibacker was more of a filler than a bonding agent. I talked to another tile guy who said I was doing it all wrong and that the tile will be breaking loose within a couple of years. He said I should have used a crack isolation membrane such as Schluter's Ditra product. He said that my only hope now would be to use a crack isolation membrane over the hardibacker, such as Mapei Mapelastic HPG. If I would have remembered previous advice, I would have probably used ditra instead of hardibacker. However, I completely forgot about ditra and began laying down the hardibacker. A good portion is already installed, so it is too late for ditra at this point. Unless you know of an easy way of removing hardibacker that has been put down with thinset and screws on a 4" grid? :) I talked to yet another tile guy who said I should use a better thinset for adhering the tile to the hardibacker. He said the Versabond was OK for the hardibacker to Advantech but I should be using the Mapei Kerabond+Keralastic for the tile. My questions are as follows: 1. Should I be using an acrylic admix mortar to lay down the hardibacker instead of the latex mortar I'm currently using? 2. Are the 3/4" screws on a 4" grid enough or should I also hit it some more with an air stapler using 3/4" staples? 3. Do I really need to tape off the hardibacker seams using a glass fiber tape as recommended by hardibacker? 4. Do I need to use a crack isolation membrane over the hardibacker because of the radiant? If not required, is it recommended? 5. Is Versabond a suitable thinset for the tile or should I be using the Mapei Kerabond+Keralastic product instead? I'm not trying to take the cheap way out. I want a floor that lasts while maintaining the efficiency of the radiant. I'm willing to do what it takes as long as I know it's going to make a difference. Thank You

Hi: We want to tile a basement floor that has a drain. The concrete floor slopes toward the drain, as expected. I've tiled level floors, but what special tile or technique do I need to know about to tile a sloping floor? Thanks.