Building a shower requires knowledge about both plumbing and construction, so it's typically the kind of job best left for the expertise of professional installer. Whether you're going to attempt it yourself, or you just want to get the ball rolling, preparing the area for the installation of a new shower by tearing down the old can be a job for a do-it-yourselfer.
Taking out an Existing Shower
Before you demolish the existing shower area, take a few steps to ensure safety. Gloves, safety glasses and protective clothing should be worn at all times during the tear down of the old shower.
You may want to decide before removing the existing shower whether you want to have installed a pre-fab shower system or use the existing tub and plumbing. Pre-fab systems are those that are designed to be placed in the area where the existing shower was. They come with their own wall and assembly and are custom measured to fit in the old space.
Remove the Showerhead
If you choose to remove just the old shower, shut off all water and remove the showerhead. Place a cap on the showerhead to prevent any leakage after the system has been drained.
You also want to detach all of the faucet fixtures in the shower as well in order to make way for the new fixtures that you chose. The fixtures tend to screw off or can be removed using a plier.
Remove the Tiles
Using a chisel and hammer, pop the old tiles off the wall. This will give you access to the wallboard and protective membrane where the vapor barrier was installed. You want to carefully tear the walls down to the studs in order for a new vapor barrier to be installed and a new wallboard. You should also check for mold and other organic build up in the wall studs. This can be treated with a bleach and water solution.
The vapor barrier keeps the walls from becoming compromised due to the build up moisture from the shower use. Building a new shower allows you to inspect and test the existing plumbing and ensure that the previous installations were done properly.
Bring in the Professional
Once the shower has been taken down to the minimum bare walls and you have clean-up the demolition area, it is time to have the plumber and installer in to take measurements and make additional assessments. Depending on the selection made for the replacement shower and tub assembly, the installer will need to determine the proper measurements and any adjustments that need to be made.
Improper installation of a shower requires attention to detail and some knowledge of plumbing and moisture protection. You should not expect to know these things right off when first attempting to build a shower. Understanding how your shower works by tearing out an existing one however will help you understand the level of detail that goes into the shower build.