I am about to do this same project.
I found directions on the site below. You must build a support structure.

I am going with a 25" sink where I had a 33"

Here is a link that might be useful: DIY Network Farmhouse Sink Install

cella .... THANKS for those directions, I will have to show them to my carpenter.

So, COULD YOU HAVE installed a 33 inch sink??? Or did you have to downsize because of the support boards???

I almost ordered a 33 inch sink; and now I think I only want a 30 inch one; but I don't know how much repair work will have to be done to the outside of the front of my cabinets. Maybe just a trim board or two, I'm thinking.

Especially if you get just one big bowl, I think 33" would be tooo big .... hoping the 30 inch will work for me.

THANKS AGAIN :)

jody

I didn't put my sink into an existing cabinet but I can't see that there is any difference between a brand new cabinet and an existing cabinet. One is already bolted in, the other is just bolted in "today". Measure the inside of your existing cabinet. Your sink will have to fit inside the box. Your supports are under the sink, not to the side, back or front.

Will this be an apron front sink? If so, do you have the space to drop it into your existing cabinet? You have the fake drawer fronts, I presume, and two doors below those? How deep is the sink you are planning to get? You will have to cut the front of your cabinet if you are goign with apron front. So many little details to know before I can give you reliable advice. Long story short, if the sink will fit inside the cabinet box, you should be good to go. You will want to pull an apron front sink forward about 2 or 3 inches. Your carpenter can use two different methods for cutting the front out of your cabinet. Either scribe around the front of your sink or take the fake drawers and the frame holding them out completely and install a shelf to hold your sink.

Jody,
I found an old posting from this forum that's great. It has even more info and links.
One poster says not to build a platform like pinch me mentions above. I like the idea of a platform but I can see where it wouldn't be good once you cut into it for the plumbing below. I worry though about the sink breaking when under pressure. Also, I worry about a disposal...

The reason I went with a 25" sink was because it was the least expensive option - I purchased the only single-bowl ceramic option available at Ikea - $200. I wanted to save more money for appliances. I figure if the sink gives out, I will upgrade to a more expensive option. And yes, I agree, going from a double sink to a sink bowl will make the loss in inches negligible.

Here is a link that might be useful: Forum link

The biggest issue with retrofitting a standard drop-in sink cabinet for a farm sink isn't the horizontal width of the sink -- if the sides fit into the cabinet, you're good to go -- but rather the vertical proportions. Often the doors on a regular sink cabinet are too high for the farm sink to fit over them and still undermount or flushmount it with the counter. You can always upmount the sink (i.e., let its sides and back stick up above the counter surface) but that seems to be a less popular option these days.

In terms of a platform, you don't build a solid platform with a floor, but rather cleats set onto the sides of the cabinet and 2x4s laid across them at the front and back of the sink. It doesn't interfere with the plumbing at all.

Good luck!

If you are still considering the copper sink then you don't need to have a frame support the underside of the sink bowl as you would with heavier materials. Mine is supported only on the sides and I never feel any "give" on the bottom of the sink even with heavy cast iron in there.

I have a 33" copper sink and it replaced a double bowl sink of the same width. It fit nicely into the cabinet with only a small trim to the sides of the old tilt out compartment. To complete the install, we used shorter doors from a bath vanity that will be replaced.

Thanks everyone for your help on this subject.

I know I will have to shorten the doors under the sink. The doors are like a frame with an inset in them; and I'm thinking I will have the oak inset taken out, the frame shortened and put in some type of lattice (still working on that one!!).

I don't think I need a sink as big as 33 inches if I get a single bowl; and think a 30 inch just might look better in that space.

Yes, I am still going with copper; but before I buy, I need to have someone figure out what to do with the extra 3 inches of space I will have (1.5 inches on each side of the sink) .... because the sink will be 3 inches less wide than my old one.

I am going to print out all this info and let my carpenter read it (my husband too!!).

thanks again :)

jody

If the cabinets are going to be painted you can just add a 1.5" piece of wood on each side. After it is filled and painted you would not see any difference. If you are refinishing with a wood stain it would be best to replace the entire face of the cabinet so the splice would not show.

That's a good idea with adding lattice to the door panel, very retro looking. You can also buy new unfinished doors in almost any size. They have many styles available so one might match your existing doors.

steff 1 ~ My cabinets are stained Oak (a medium brown called Fruitwood) and were built on-site by my dad. They are still in good shape, but will need to be re-varnished. I would LOVE to paint them; but don't have the courage to do that yet.

Sooo, I have to find out just how easy (or difficult) it would be to add that little piece of wood to each side. I got the idea for the lattice while leafing thru some magazines a few weeks ago. I can either go wood lattice or metal lattice ~ I'm thinking the metal might work good with the copper sink and it is quite a bit cheaper than the wood lattice they sell specifically for cabinets (I checked the Rockler website ~ they have stuff like that).

Again, I so appreciate all the advice you've given me :)

jody

My carpenter did this for me. My old sink was a standard double sink, 32" I think. He built a frame underneath for my new Franke 28" farm sink. He made some filler pieces for the sides of the sink, and lowered the doors underneath a tiny bit. Here is his framing.

Here it is now - it has worked out really well.

We recycled a wall oven cabinet for our farmhouse sink base. Even with stained wood finish, you can get a very nice retrofitted look. Any good carpenter will be able to scribe those side pieces to fit the sink edges.

Circuspeanut's cabinet looks great with the wood filled in. Emphasis on good carpenter there is important. Both of those examples are nice.

Especially since your cabinets were built by your dad, then a well done matching fill in would be a good choice and become part of your kitchen story. I was visualizing a stock cabinet look. Your idea works better.

On the painting, some things just have to be left as they are. We've had a couple threads here recently about how some of the finishes we most want to get rid of are coming back anyway.

Looked up the lattice panels and there are a lot of nice ones out there. Either wood or metal look like good options.

prill ~ thanks for those great *how-to* pictures. Your sink looks great in that space ... love, love, love white painted cabinets (but just not there yet!)

circuspeanut ~ thanks as well for your pics. Love your smaller sink. That is the *look* I want. So hoping my carpenter(s) and or my one son can help with this :) And I also LOVE your copper countertops ~ so unique and beautiful!!!

steff 1 ~ yes, the Rockler site has lots of options for my base doors. And I really think, when done, the lattice will look better than the plain Oak panel in there. The kitchen I saw in the magazine, ONLY had the doors under the sink in lattice and it looked fantastic. Hoping to capture that *same* look :)))

jody

I am looking at doing the same thing so I was googleing around and came up with this website that custom makes apron front sinks that retrofit into existing cabinets. They only have stainless and copper but it looks pretty slick and the sink supports itself by resting on the cabinet so you don't need to build up from the bottom. Unfortunally they are really spendy but you wouldn't have to pay to have your cabinet modified so I guess you would save a little there.

Here is a link that might be useful: Apron front sink retrofit option

Well done except you may run into issues with the plumbing on the sink. It is installed in an "S" trap configuration, which means it stands a good chance of siphoning and losing your water seal in the trap.

You will want to add a studor vent (air admittance valve) under the sink to allow proper ventilation to relieve the trap from siphoning.

Go to your local hardware store and ask for a air admittance valve. Studor is the best brand and most professional plumber's choice. The instructions on the package should show the installation method. I have also added a link to the manufacturers site to see how it works. You will need the mini vent.

Good luck.

Here is a link that might be useful: Studor Vent