What are Shower Thresholds and the ADA?
ADA shower thresholds are devices that have been used within showers at least since the advent of ADA law. What is a shower threshold? It is not the cast iron or tile curbing for a shower. It is not the tile on the floor inside the shower. Rather, it is a horizontal metal plate that is typically recessed into the shower floor and which allows the water to drain through. The ADA requires that this plate be sloped slightly toward the drain, which it typically is. The slope is required so that the shower water quickly drains toward the drain in the shower floor when the shower is in use . If the shower threshold failed to slope toward the drain, the water could collect and remain, creating an unsafe walking surface where one might easily slip or trip.
The shower threshold must be level with the remainder of the bathroom floor in order to be in compliance with ADA. If, however, the threshold is still too high (as it often is), it can make transitioning between the nearby floor and shower difficult and potentially hazardous. A complementary ADA compliant device for a shower threshold is a slope protector, which is simply a ramp that allows an easier transition between the bathroom floor and shower floor and which also protects the shower threshold.
Key ADA Rules for Shower Thresholds
The ADA provides specific design requirements for shower thresholds, which are located at the entrance to the shower and define the boundary between the dry area and the shower area. In 2010, the Access Board included revised requirements for shower compartments that contain a seat or grab bars, a tub with a shower attachment, and roll-in showers. A raised threshold is required for transfer showers (inaccessible showers are also required to have a raised threshold).
Standards relating to barrier-free design require that a shower compartment have a threshold that is at least as high as the threshold on the tub. For roll-in showers, the threshold must be less than 1/2 inch (13 mm) high, must be sealed on the inside to prevent leakage, must have a beveled edge with a maximum slope of 1:2, and must have a curb that has a rounded cross-section. For wheel-in showers, the threshold must also comply with the slope and surface-exposed requirements. The maximum permissible height of a roll-in shower threshold is 1/4 inch (6.5 mm). The surface-exposed height for a roll-in shower threshold is the same as the minimum surface-exposed height: 3/4 inch (19 mm).
The recommended materials used for shower thresholds are concrete, granite, marble, foam polymers, and plastic. Marginal products include bricks, precast concrete, stainless steel, cultured marble, and aluminum. These do not meet the recommended requirement due to their susceptibility to corrosion, the tendency to stain when wet, and for being too heavy to install.
Advantages of ADA-Compliant Shower Thresholds
The benefits of shower thresholds that comply with the ADA are numerous. First and foremost, they improve accessibility and safety for the elderly and those with special mobility challenges. Entrapment, a leading cause of injury and death, can be reduced in communal showers, such as in assisted living facilities. They also limit mold and mildew growth (which leads to slip/slip-fall hazards) by boosting drainage functionality. Featuring slight slopes versus step-ups and curbs, they can also save space without compromising ease of use. Showing residents that you care about their safety can aid in retention efforts and grow your positive reputation, as word-of-mouth is one of the quickest ways to encourage new residents to check out companies in your sector.
How to Create Compliant Shower Thresholds
When implementing ADA-compliant shower thresholds in a new construction or during a renovation, careful consideration is essential to meet the ADA standards. The process typically begins with ensuring the appropriate slope of the shower area, with a maximum slope of 1:12 in new construction and preferably flatter in renovations, such as 1:16 or 1:20.
Next, the subfloor must be pitched to ensure runoff toward the threshold and away from any pool areas that exist. If a curb is present, then the necessary pitch is determined so that the water flows from the rear of the shower to the threshold and opening, with the runoff leading to a drain .
During the design phase, it is also important to choose an appropriate surface material for the shower threshold. For instance, a slip-resistant tile may be chosen, that is installed to create a surface that is flush with the floor and meets ADA standards.
Finally, consult the local code to determine if any additional requirements may apply, including drainage and plumbing standards that apply to the ADA-compliant shower thresholds. These codes dictate the slope requirements, the materials to use, and any other requirements to meet the more stringent ADA and CARB standards.
Common Problems and How-To Fix Them
Common challenges with shower thresholds are many and varied. The biggest is stemming the water, then the slope gradient or run, the corners, the pitch, water debris on the floor and much more. So how can one filter through the challenges and create a solution that protects the building and almost effortlessly tests for leak potential?
Most are familiar with the visual triangle graphics that appears when code studies are done. On the tile or construction drawing or a mock up, you will see the triangle appear demonstrating the potential for water migration. Many times we have had to stop construction after the initial assembly is up because water testing proved to create undesirable results. That’s when we create mock ups and schedule audits for water testing.
As much as I would love to have this be a perfect scenario, it isn’t. We are in a time crunch and are working with a budget. The site built mixed materials on the floor are very challenging – and yes, we’ve tried those faux corners formed on the job site. The carpet tile or hard surface transition can also be a problem area for water migration onto the floor.
When I refer to "we," I am referring to all professionals involved as a construction team. Water migration is from the lapped area to the drain. To create a tight seal in that lapping process and below the entry door/threshold, it will depend upon the type of shower pan or liner used. Pre-formed sheet pans or piers can appear to be a great solution at first. The pan assembler lays down a layer on the slab, tile setter comes in to add another layer with thin-set, and then the tile setter does the tile work. Great, right? Not quite, because the issue with a shower pan is that they are flat, so when you go to drain the runoff, the transition has a slight slope beyond to move the water to the drain. That means, if you shower, the water will not "sense" the slope or incline and will therefore move towards the door and into the lapping area where that triangle of concern is.
The trick to avoiding this issue is to modify the mock ups and communicate to all parties, from the architect or designer to the subcontractors, to build a slope. It may be a small rise – even a half inch or less – but includes a sloping build-up from the perimeter walls or return of the curb.
Shower curbs are made with an incline from the drain to the curb itself to drain water to the outside. As simple as this sounds, it can create an issue if the height of the curb is not built tall enough and the drain area isn’t sloped sufficiently. This situation will cause the shower head water to pool in the shower and then rollover the curb, ending up on the floor. A solution to this is to use a pivoting shower door or bi-fold door, which will not continue to pass the water once the shower curtain rod is out of the way.
The direction and pitch of the shower head is next in line for regular problems and solutions. While designers and architects are well aware of the window size due to height and conflict with the opening, it impacts the shower area. To avoid this issue, and the potential for an ADA issue where the ability to stand under the shower head is difficult for individuals who are less than four foot, use a wider window.
Porous and water retaining material is good in the shower for drainage, but there is a downside. As small dirt or debris collects in the porous holes, they cause clogs and block the efficient drainage process. When the water begins to overflow its berth, this is when water migration becomes a serious problem. The solution is to clean the surface regularly, so that it will maintain its drain capacity and reduce the chance of water migration.
As much as we would like to think that our use of sealants will completely block and prevent moisture and water evaporation, it will not. Tile and grouted surfaces will be porous due to loose grout from set pieces and even in the curing process. So while the sealant can stop the big bulk and most water that will end up on the floor, it cannot stop every drop of moisture.
Case Studies of New Spacer’s Successful ADA Shower Installations
Along with successful installations of our ADA shower thresholds, we have been involved with several new construction projects. Two of the most successful projects were large hotels that needed dozens of shower thresholds for their accessible rooms. One of these hotels was a large five-star resort located in Maui, Hawaii. The general contractor contacted us after an awful experience with an alternative product. Due to the narrow bay on which the hotel was located, the company had no other choice but to install pre-made thresholds that were manufactured by one of our competitors. Given the incredible humidity on Maui, the product line had failed at a rate of 50 percent during its first year. After conversations with the general contractor, it was decided they would pull out the pre-made and install our ADA shower thresholds. The unfortunate assembly line of de-molding, cleaning, sealing and installation would be a thing of the past, and a product would finally make sense for their state-of-the-art kitchens. As all of the showers required curbless thresholds, we used a three-quarter-inch recessed base tile and our low-profile ADA-grade threshold. We make a point to always review the installation of our products with the installers and contractors and this is especially important for curbless entries. The single source responsibility concept worked flawlessly and, to date, none of the thresholds have failed . The complete lack of callbacks has allowed the general contractor to ship out large orders without a second guess. Another successful ADA shower threshold installation was a high-rise apartment complex in New York City. High rises can have incredible challenges when it comes to low curbs. The difficult nature of low curbs comes down to the inability to prevent the runoff of water to areas outside of the shower space. Even though we’re eager to assist with any design, we had to pay extra attention to this job. After reviewing the bathroom layout, we determined that our ADA shower thresholds could be not only the perfect solution for low curbs, but also for small bathrooms, where every inch needs to be utilized. By using a slightly extra long threshold, we were able to make the most of this space without flooding the bathroom. With little else, the design fell into place and the low curbs functioned well. When accessed from a wheelchair, the ADA shower thresholds work at the same flow drainage process as with a regular sized wheelchair and grab strap. There are no additional steps needed for wheelchair access or barrier free design. We feel that on-time project delivery, premium quality products and betters products at a lower price will encourage designers and contractors to turn to us first for their ADA bathroom needs.