I am remolding my bathroom and am turning my tub into a shower. Where do I buy the rubber membrane to put down under the concrete shower base. I have asked at Lowe's and Home Depot but they don't know what I am talking about. Thanks Brenda

Check the plumbing section at Lowe's or home depot that's where its usually stocked there. If no luck a tile supplier or plumbing supply house may carry it.

Brenda, the guys at Home Depot apparently do not know what they have on hand, HD sells membrane right in the shower aisle. I have to ask, why are you planning on a scustom mud shower pan, they are a bear to install correctly for a 1st time DIY project. Swanstone makes a fiberg glass shower pan made for replacing a tub. I have done about 5 of these , they are a breeze compared to a mud pan. Swanstone Products (http://www.theswancorp.com/?search=3260+retro&x=17&y=8)

Thanks for the compliment Brenda. Instead of a finished floor like the Swanstone you can by a foam shower pan that is ready for tile. http://www.shop.showerbase.com/category.sc?categoryId=2 This saves you lots of trouble and eliminates the rror some folks make doing a custom pan from scratch.

I checked out that link for the shower basin, saw the price and OUCH!! For less than the price of just the basin, you can get a complete Kerdi shower kit. Kerdi is hands down, the Rolls Royce of tile shower systems and the kit comes with the preformed tray (available in an offset configuration for retrofitting into an old tub location) and preformed curb and your choice of drain finish. It comes with enough Kerdi membrane to create a shower system that is 100% water and vapor proof behind the tile, not behind the substrate as you get with plastic behind cement board walls. It dries out quicker than any other shower and takes no more skill than being able to apply wall paper. You'd especially love the drain. Not only does it have a square grate instead of circular, it also is fully adjustable up/down and side to side.

Tile-ExpertsKERDI, DITRA and Nuheat.  The Schluter Experts! (http://www.tile-experts.com) is a great place to order the kit. Dave Taylor's service is outstanding. He even personally delivered the kit to the house of one of my customers.

As a side note, since tubs only require a 1.5" inner diameter drain, when you pull the tub, you might encounter that. Showers, though, require a 2" drain. That 2" size requirement carries all the way to and including the intersection with the main stack. You can't just use a reducing coupling from 2" to 1.5" to make it work.

Not all HD's and Lowe's carry the dam corners. If yours does not, they are available online at Noble Company Sheet Membranes & Shower Installation Products for Tile & Stone (http://www.noblecompany.com) and Noble also has clamping ring drains to be used with pvc or cbe liners with both circular or square grates in a decent assortment of finishes. One other thing about their drains is they don't ruin the look of a beautiful tile shower with a cheesy, cheap looking pvc ring surrounding the drain grate. If you only want to do one layer of mud, Noble also has preslope trays so you can skip the first mud layer and only do the setting layer. If forming the curb out of concrete seems intimidating (you CANNOT make it out of cement board unless the idea of hole in your liner doesn't concern you), they also make a tile ready curb that slips over the liner wrapped stack of 2x4's used to form the curb.