Shower Niche
The shower niche is very prominent design component of your bathroom remodel. While it is can be a very beautiful and identifying focal point, it also provides a place to store accessories that are needed during normal shower usage. The shampoo niche is an extension of your own imagination, giving you the freedom to add a very large creative canvas or a subdued version serving more function than form.
Frame
The frame of your shower niche is very important, relative to the desired finish size. A shower niche can fit within a set of wall studs, which are usually a standard width of 16 or 24 inches. Taking into consideration the thickness of each component that makes up the shower niche, backer board or cement will be about a 1/2 inch, thin set adhesive can be up to an 1/8 of an inch, and depending upon your choice of tile it could be from 3/8 to 1/2 inch, with a total finished width of 1 and 1/8 inches on all four sides of the niche. As an example, using a standard width of 16 inches between wall studs, the final usable area of the shampoo niche would be 13 and 3/4 inches square. An alternative solution would be to determine the width and height of your finished shampoo niche and then using wood pieces, preferably pressure treated, that are cut to length and fit them into the wall studs. It is important to note, that pressure treated wood is going to dry out and can be prone to twisting, therefore, you will need to determine if it is a good choice and within the building code requirements in your area. The goal is not to lose any structural integrity and provide support with length running horizontal wood.
Cement Over Niche
Starting with a solid structurally sound shampoo niche, you can install wire mesh over 15lb. felt paper and begin applying the cement scratch coat to the interior and exterior niche walls. The intended goal is to have a straight application of cement that can be a perfect base for a tile installation. The finished product should have straight edges where the shampoo niche walls meet with shower walls.
Backer Board Over Niche
If you choose to proceed with a backer board base inside the shampoo niche, there are several things to consider. Assuming your frame is square and level, you should have a good starting point to ensure your backer board pieces after installation maintain the same square and level. The backer board should meet the shower walls in a linear manner and there should not be any gaps between pieces. Where screws were used to install the backer board and at all joint seams, mud pack the openings with a thin set, deck mud, or silicone, and a fiber mesh that is alkaline resistant. Since the shampoo niche will be within the wet area and experience further moisture from shampoo bottle storage, it is suggested that you apply a liquid waterproofing membrane over the entire shampoo niche area. This should be a consideration as part of your entire waterproofing strategy, but not to be overlooked since the shampoo niche is most often in the path of direct water from the shower head and sees indirect moisture from water splashing from the body and dripping from the hands.
Pre-Manufactured
Perhaps the easiest construction of a shampoo niche is to purchase a pre-manufactured form that can be screwed into the wood frame. While you still have to cut the frame and provide structural support for the pre-manufactured version, it comes with the added advantage of not having any inside seams and does not require screws, other then to the exterior where it is installed.
Waterproofing
The waterproofing method you choose for your shampoo niche will be encompassed by the entire strategy you have chosen for the shower area. With this said, if you choose to locate a water resistant barrier behind your shower walls, than the shower niche will take this into consideration during construction. If you water resistant barrier is applied to the exterior of your shower walls, then waterproofing the shampoo niche will occur as a result of this strategy. It is important to remember that you should never have two water resistant barriers, one behind the shower wall and one over the exterior of the shower walls, since this will create a “moisture sandwich”. Where a water resistant barrier exists behind the shower wall, you will have to weigh the consequence of applying a liquid membrane to the shampoo niche in order to add another layer of protection from moisture.