Can this be done?
In this kitchen remodel I want to put as big (wide) a stainless single bowl sink as I can into a 30″ sink base. I have seen 2 candidates:
elkay 2816 and a Kindred KSS 5u, both of which have a inside bowl width of 28″. The recommended cabinet size for these sinks is 36″, but I don’t see any theoretical reason why they couldn’t fit into a cabinet that has a 28 1/2″ inside dimension.
As long as take care in mounting the sink into the roughtop (granite will be the countertop surface) before fastening the rough top to the cabinet, are there any good reasons why this should not be done?
Thanks,
Joe
Replies
Is the cabinet stand-alone or part of a group? Because if it stands alone you are going to have a mighty narrow countertop on the sides of the sink. A further consideration is the space for the mounting flange and the clips under the sink. I would guess that the manufacturer's have pushed the practical limits to the wall with their reccommendations (at least that is their usual modus operandi). Take a careful look before you buy. Sometimes you can fudge a bit taking some out of the tops of the cabinets on the sides especially if they are drawer units.
the 30" cabinet is part of a run: dishwasher on one side, drawers on the other.
Are clips really necessary (or even used) on an undermount sink? Isn't it the weight of the granite that keeps the sink in place?
No the sink is attached to the bottom of the granite, and it needs to be sealed with silicone too (or other similar sealer). Holes must be drilled into the granite, you better find a display and take a look under there.
I trimmed out a kitchen last year with granite countertops and an undermount sink the size of a horse trough. Although they had drilled the granite for the bolts and clips, what they actually did was to cut away just enough of the top of the sides of the cabinet so the sink was cradled by the cabinet side cutout and held in place by the counter top. Silicone was used to seal the deal. The granite guys weren't real happy about the thin edges front and back of the sink; the top can break if it's too thin in those areas. They like to say 3" per edge, but I think that's an ideal figure in ideal circumstances.
I just did a remodel and clips aren't used for an undermount sink. What I did was mark the cutout in the plywood substrate, cut it out with a jigsaw, and use a router to slightly cut out the part of the plywood where the sink sits. This got the sink top absolutely flush with the plywood, and this, in turn, got a better granite fit.
John
I've done that. The way I and my granite guy do SS undermount sinks is this. I cover the tops of all the base cabinets with 3/4" ply. At the sink, I router down so that the top of the sink's mounting flange is flush with the top of the plywood. The sink is supported on all sides by the plywood. The granite guy drops his usual adhesive blobs all over the plywood, and runs a bead of caulk around the top of the sink. When he sets the granite, the caulk makes a nice wide seal between the stainless and the granite. The caulk squeezes out as he sets the granite, and he just wipes it up. It makes a simple and secure installation, both for the carp and the granite guy.
Jamie,
I used 3/4 ply in my remodel and it was a mistake.
It should have been 5/8ths. The reason? The granite is 3/4, and the bullnose (or any other edge) is doubled, so is 1.5 inches. With the mastic (or whatever it is that the granite guys use), the granite actually sits slightly above the plywood. If the plywood used is 3/4, the finished granite will be slightly above the plywood, and you'll both be able to notice it and to feel it if you put your hand on a bullnose (like gripping a handrail).
John
Secondly, if you rout out the plywood for sink lip thickness, then the stone will not sit tight against the sink. I suggest just dropping the stainless sink into the rough cutout, and then the mastic thickness will match the sink edge thickness.
I routed the plywood for the rim, making sure that the SS was absolutely flush with the plywood. There is absolutely no play in the sink. Tight as a drum.
If the sink is set on top of the plywood, the layer of mastic will actually be very thick and it'll be hard to keep the granite absolutely level ... 10 feet away. Even so, with the mastic, my 3/4 inch plywood shows belowthe granite. The substrate should be no more than 5/8ths of an inch IMO.
John
The plywood method sounds slick but what do you do if the sink needs to be replaced? Maybe cleat the plywood in place so it can be removed from underneath? Obviously this won't happen very often but once would be enough for me.
Yes, that's the way I mounted my cast iron sink. With the ply substrate and granite top there is no way you can remove the sink if you want to change it. But then how likely are you going to have to change the sink? Just be safe I mounted it as you have outlined. I didn't use a ply substrate because the granite is 1 1/4, so I set the sink in ledgers bolted to the sides of the base, making sure the top of the sink is flush with the top of the base.
John, you brought up a good point. The silicone they use to set the top does have a thickness to it. If I were to set a sink on a ply substrate, I'll use 5/8 for sure.
Tom