: My house is built on a concrete slab. I want to modify an existing bedroom into a second bathroom which will require going into the existing slab to find my drain pipes. Is this a pretty common and acceptable practise? Do I need to worry? Can I use ready mix crete to fill in after the new pipes have been joined to the existing pipes? Please bare in mind that I am having a supposedly professional plumbing company do the work. Thanks for your answers. Dear Bill, What you have described is how it is done. A good way to remove the concrete slab is to hire a concrete cutting outfit. They are listed in the phone book. Using a diamond saw cooled with water, they can cut the slab, loosen the pieces with a demo hammer and lift out the concrete from the area being plumbed. This damages the existing slab less and is less dusty. It is also easier to pour the concrete patch back in place. (redi-mix is fine) Regards, Terry Love
