This will be, hopefully, the final drain detail on this subject. But never say never, right? That’s floor covering for you. We all need to pay attention to the particular job site conditions we are confronted with on a daily basis. Most of the time moisture problems are from the bottom up. A green slab, with the resulting high levels of water vapor emissions, is just one type of several possible moisture-related problems found in the field.
What I have tried to address in this series is the moisture issues from the top down in a typical commercial kitchen environment; mostly dealing with drain detailing, which I have found over the years to be a weak link in a lot of installations.
Photos 1 and 2 show the reason drain rings should be used in wet area installations. If you believe in the old saying, “The weakest link of any floorcovering is the seam,” then treating the cutouts for your drains and clean-outs as if they where seam areas just makes good sense. Not to mention that all the time you spent under scribing and cutting the openings for a good fit should not go to waste.
Photo 3 shows a router being used to recess the drain ring properly. This is done so that you don’t create a tripping hazard and allows for proper water runoff into the drain fitting.
Photo 4 shows the outer edge being cut first, while Photo 5 shows the field of the ring being removed/relieved. You must use extreme caution when doing this! A high-RPM router will not last long if you run it into the brass drain housing. Removing the drain cover will help prevent this from ruining your day and your expensive router unit. If you can’t remove them or have never before used a router, then wrap the lip with duct or electricians tape to prevent your $20 bit from getting trashed, and please put on safety glasses. A blind mechanic will have a hard time finding finish work, so protect your eyes.
Photo 6 shows the radius cutout to the proper depth. Photo 7 is the finished fit. Keep in mind that the rings should be installed with counter sunk stainless steel screws for a flush look, and use lead sinkers in the concrete to screw into. I don’t think that wooden dowel rod and epoxy will work in this wet environment.
Tapcon brand screws would work if they had stainless steal. But I have yet to see those! Also it is best to install the rings when the adhesive is still pliable; still in a green state, not yet hard. This ensures that the ring has a pinch fit around the drain opening to ensure a good seal. If you have no other choice but to install them after the flooring has been laid, know that it will take much more time but still be effective.
Photo 8 shows a properly installed ring that has been in service for some time. Photo 9 is a side view showing the correct slope and fit. This drain will give years of service and prevent moisture from getting underneath your floor covering.
Photos 10 and 11 are of a cut away showing a typical drain that details another important step. Can you make the call on this step?
This is the sealing of the drain ring with the use of a urethane sealant/adhesive. The urethane type is best for water resistance and has better adhesive qualities than silicone or blends.
Remember the silicone bandit in the first article? Typically your urethanes dry faster and stick best, in the long term, in the high traffic kitchen areas.
Photos 12 and 13 are square sink drains; do you think they should have the same type of detailing as the round? “You Make the Call!” Thanks again for reading, and have a great day!