Totally Drained: Working with Linear Drains
Shower drains, when installed and waterproofed properly, will do their job for the life of the installation. When not done properly, the results can be catastrophic—especially when installed over a wood subfloor. That’s when one of the definitions for “drain” from the Merriam-Webster Dictionary will first come into play for the tile setter (“to exhaust physically or emotionally”) followed by another definition (“to empty by drinking the contents of, such as to drain a mug of beer”) after finding out their drain leaks (Photos 1-4). In many cases, these types of failures are slow to manifest themselves and can take months before they’re noticed, and that’s why wood subfloors may need to be removed and replaced along with an entirely new pan, tile install and even sheetrock and paint work.
With curbless/barrier-free showers becoming more and more popular, and with larger tile finding its way into showers (Photos 5-8), we’re seeing more linear drains being installed. If tile setters are having concerns with 4” to 6” drains, just think what a 48” drain will do if not properly installed and waterproofed. Be aware that there are quite a few manufacturers of linear drains, with differences in their construction. Some have been designed with the installer in mind, making it easier to waterproof. Others can be a challenge.
We’re seeing a lot of retrofitting of pans with barrier-free entries and linear drains. Unless subfloors have been recessed prior to installation of the shower pan, it can be a headache for plumbers, carpenters and especially tile setters. When the tile setter has to work with a linear drain that’s been placed by a plumber who is not familiar with how to properly install/waterproof, or a carpenter who doesn’t understand the amount of slope required for a shower pan (1/4” per 12” run), it can lead to even more headaches and potential leaks.
One of the biggest headaches is when placing a linear drain right next to a wall. The wall side can be very difficult to waterproof. Photo 9 depicts one such headache; the linear drain was placed too close to the wall by the plumber, who also set the drain prior to the installation of water-resistant sheetrock (Photos 10-11). And yes, that is sheetrock topping used on the joints, instead of a waterproofing product.
Shims were placed on top of the existing joists and bracing in between the joists to allow for some slope by the carpenter. However, by doing this they raised the elevation of the pan subfloor above the main subfloor. By the time you add a deck and tile to the shower floor and main floor, the tile flooring would be built up to the point that the entry to the bathroom would contain at least a 1” to 2” barrier. Also, the linear drain was specified with extensions on each side because it wasn’t long enough to go wall-to-wall. If you look at the extension, how is one supposed to waterproof it when all that’s there is a metal channel? (Photo 12)
This is where it becomes essential to understand each manufacturer’s drain requirements, because what happened in this case is all the work by the plumber and carpenter had to be removed and redone (Photo 13).
Manufacturers are beginning to address retrofitted, barrier-free entries (Photo 14). One company I saw at Coverings in Orlando last month was Rapid Recess. They manufacture a bracket system that makes recessing a subfloor quick and easy. You can check them out at www.rapidrecess.com.
Special thanks to Antares Tile in Lafayette, Colo., for providing some of the pictures used in this article.