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Nothing will give you a cleaner line and a cleaner countertop than undermount sinks. Without the sink lip on the countertop, there is nothing to trap food and bacteria around the sink. Undermount sinks are used in conjunction with solid-surface countertops. One reason is because the counter must be strong enough to hold the sink. The other is the finished edge inside the cutout for the sink.
You can purchase undermount sinks in many various configurations from a single bowl to a triple bowl. They also come in several different finishes, from stainless steel to marble and stone. The first step to installing your sink is to find the one that best fits your needs. -
You should have the countertop cut to the specifications of the sink. Cutting a solid-surface countertop is not the job for the average homeowner and is best handled by a manufacturer or certified installer. After you have your cut-out though, you can take over. You will need a 2-by-4 board longer than the opening of your sink and a couple of bar clamps to get started.
But before you do, clean the underneath of the countertop very well with a brush to get rid of all the dust from cutting and polishing it. If this is allowed to remain, the adhesive will not work.
Place the board over the sink opening. Then place a bead of clear silicone adhesive to the flat rim of the sink and line the sink up under the countertop. Put one end of the clamp on the board, stick the other through the drain opening and clamp partially tight. Do the same on the other side if you have a double or larger sink. Check to make sure the sink is perfectly aligned before you fully tighten the clamps. Silicone adhesive or caulk will create a waterproof seal between the sink and the countertop. It will also help to hold the sink in place.
Next mix some two-part epoxy together and apply it to the bolt posts that are next to the lip of the sink. As soon as the epoxy sets you can install the wing nuts onto the bolts and hand tighten to the inserts that hold the sink in place. Leave the clamps in place for 24 hours before installing the drain pipe. -
Install the drain basket by applying a bead of clear silicone caulk to the inside edge of the drain hole in the sink. Push down the basket and turn it a little to spread the silicone and give it a good seal. Under the sink, install the rubber gasket, paper gasket and the metal lock nut. You will need adjustable channel lock pliers to turn the lock nut and needle-nose pliers to put through the small holes above, to keep the basket from turning. Do not overtighten the lock nut or you can distort the rubber gasket and cause the basket to leak.
Next, install the tail pipe. A metal nut, which should come with the basket kit, installs over the PVC drain tailpiece. Insert the plastic washer, and then connect the assembly to the sink basket.
If you are working with a double sink, you will need an elbow here to work over to the other tailpiece from the second sink. Then a T fitting is used to bring both drains together and down to the P trap. The P trap is a U-shaped piece that traps the water at that point and blocks the sewer gases from coming back up the drain pipe and into your room. From there a pipe is connected that goes into the main home drain. These pipes are put together with compression fittings that need only to be hand tightened. There is a gasket inside that prevents leaking, and if you overtighten these large PVC nuts, it will distort the fitting and you could cause a leak. PVC drain kits can be purchased all together at your local hardware or home improvement store.
Comments
aajohnson21 said
on 6/26/2009 What bolts? This is bogus. News flash to anyone looking to install an undermount sink: The sinks don't come with bolts to attach the sink to the countertop. The first half was almost right, but a total rip from another post. Know what you're talking about before you post a How To.