Question:
Thanks for your excellent columns. Could you comment on the pros and cons of installing a surround shower vs. the “old fashion” ceramic tile? If tile is to be used, how can you avoid the problem of mildew developing in the caulking? Are there any products to minimize this problem? Also, is there less risk of water leakage down the road if tile with a copper pan is used instead of a surround?
Answer:
This is an excellent question to a very common decision that many homeowners face when renovating bathrooms or building a new home. There are indeed positive and negative attributes to the various styles of shower enclosures and we will explore several of those here.
You concern over mildew or mould growth on the grout and caulking in a traditional ceramic tile shower is a valid one. Just this morning, I spent a few minutes cleaning the mildew off the silicone above my own bathtub. It is really not difficult to do, but does require regular attention or it can go beyond the point of no return. I personally use an old toothbrush combined with spray-type bathroom cleaners for this task. If the mildew is a little out of hand, a spray cleaner with bleach helps to temporarily get rid of the growth. The only two products that I am aware for prevention of mildew may be in the original products, themselves. Bathroom silicone is available with a fungicide mixed in the caulking. This has limited effectiveness, but may be somewhat better than regular silicone caulking. For the grout, a spray-on liquid silicone is available, or often grout with integral silicone is available for slightly higher cost than traditional grout. These again will have limited effectiveness if the shower walls are not wiped down and cleaned regularly.
Before discussing the other types of show stalls, we should understand the reason that mildew and mould grow on shower walls and fixtures. Moulds require two main things for growth. The first and most important is moisture and the second is an organic (cellulose-based) medium to grow on. In a shower, these two items are in great supply. The water is readily available during and after a shower or hot bath and the soap and shampoo that we use in the shower is an excellent growth medium. To prevent mildew build-up we must try to minimize one or both of these items. This can be done by using adequate ventilation for the area to reduce the moisture in the bathroom, and secondly wiping down or cleaning the walls after a shower may make a significant difference in the appearance of mildew. Alternatively, a squeegee may be used on the tile walls, but it may not be as effective in removing soap residue from the grout. If we are diligent in wiping the water and soap off the shower walls, there should be little mould growth and the tiles will keep their desired appearance.
The reason for use of tiles in a shower is their excellent moisture resistance combined with aesthetic appeal and almost infinite choice of styles and colours. This is what we give up in a pre-formed shower unit. Most high quality shower units are made out of fibreglass acrylic and come in a very limited selection of colours. There are also, low-cost vinyl shower and tub surrounds, but I don’t recommend their use. They are easily installed by using adhesive over solid walls, but are not very durable and have a limited lifespan. One-piece laminate surrounds or cultured marble slab surrounds are much better quality, but are more costly and must be installed professionally. Despite this limitation, these upper end units are very durable and can be very low in maintenance. The best ones are one-piece fibreglass-acrylic units that are installed directly over open studs. These are ideal, but may be difficult to install in your retrofit situation, as they may be too big to get in through existing doorways of your home and bathroom.
The alternative, ideal for renovations, is a two or three-piece unit that can be assembled on site. These shower stalls have the benefit of a leak proof solid base, similar to the one-piece units but have one drawback similar to tiled shower surrounds. There are seams that can accumulate soap, debris, and mildew just like tile grout areas. These normally have gaskets installed at the joints at time of assembly, but they may deteriorate over time and leak. Often, these seams require caulking after a period of years to prevent leakage and may require cleaning and caulking replacement.
If a shower enclosure is completely rebuilt during bathroom renovations, the use of a copper or modern synthetic pan beneath the tiles will be quite resistant to leaks, if properly installed. There are many cases where this is not done adequately and that is when leakage can occur. A manufactured fibreglass-acrylic shower base will provide even better protection, as the only area of potential leakage is at the drain. This can be used with walls made of the same material or several of the alternatives noted above.