Look at Brookhaven too -- that's what I have.

Plywood is not crucial any more than all houses have to be built of brick. Quality product, quality build and quality finish are all important and I believe some MDF is better than some plywood.

I also have some Woodmode pieces in my kitchen -- also frameless. They are the parent company of Brookhaven and a higher end line. I had a water leak in each of my sink bases in the beginning (joys of new construction and plumbers who should know when something needs 1/4 turn more). The Woodmode base bubbled and wrinkled in the wood bottom. The Brookhaven didn't have any swelling, lifting -- nothing. Just find a good brand that works well for you and that others seem mostly happy with over time (mine have been in 2-1/2 yrs - no problems).

Frameless comes in either plywood or MDF. Mine are all MDF.

Unfortunately, Brookhaven/Woodmode is not available here. I might call tomorrow about Crown Point, but it doesn't seem like that would be much of a cost cutter...

I live in Canada where frameless is standard and I talked to a few custom places and they told me they rarely sell the upgrade from furniture grade particle board to plywood in our market. For instance I don't think Kitchen Craft, a Canadian framless manufacturer, now owned by MasterBrand even offers the upgrade to plywood. I have provided a link to the gallery at the Cabico (a custom line out of Quebec) website because they specify the box type on each kitchen. You get the same warranty whether you upgrade to plywood or not - same is true for most manufacturers.

A couple of pro KD's from here have said they don't advocate the upgrade and in their experience have not found that plywood construction offers any real advantages in relation to the lines they sell. You have to remember that with frameless the construction changes so the cabinet gables usually are 5\8 to 3\4 thick while with face frame the cabinet sides are often 3\8 furniture grade particle board or upgraded to the same thickness of plywood.

It's about your comfort level but it isn't necessary to achieve a durable and attractive finished product.

Kichen Craft is one of the more available frameless lines (and it is definitely a mid-priced line) in the US. Kraftmaid does have a frameless line call Venicia. Good luck.

Here is a link that might be useful: cabico gllery

Thanks. I'll check that out.

Our KD also said there was no reason to go with plywood over MDF (we have really great frameless cabs by Glenwood, a Canadian cabinetmaker. http://www.glenwoodkitchen.com/ Very high quality and very reasonable. We have a local distributor here in maine)
After doing my research, I came down to only one reason I'd want to do the upgrade, and that is the appearance of the insides of the cabinets. If you look really hard you can see that the printed "maple" on the MDF isn't really wood (although this company's is a very good approximation, much better than Ikea, etc.) I would have preferred a real wood interior, but could not justify the ~20% upgrade cost. All of the drawers, however, ARE solid wood, dovetailed, etc.

Upgrading is a myth designed to pick your pocket. MDF is as good as plywood, and in many instances, better. It's certainly greener And cheaper. It's a win/win situation for the consumer and forest industry, and ultimately, the earth.

BTW, the insides of the cabinets can have matching wood veneers to the exterior, but I prefer a melamine interior for ease of cleaning.

Oriented Strand Board (OSB) is worth a web search and a little learning.

Your question or your quest: MDF, OSB, woodpanel products, ply.
There are professional associations out there, with factual information about all these products.

Whether frame or less, cabinets are built however.

HTH

live wire oak: Do we need to be concerned with low formaldehyde though? That is one question I am asking with respect to particle board/MDF cabinets. Actually I think I am going Brookhaven, unless Crown Point comes in on my budget. In Brookhaven both the frameless and the framed use particle board sides/tops/bottoms etc. The good thing is that Wood Mode says their PB is low formaldehyde (California compliant or something).

I am glad to read here that plywood is not necessarily worth the upgrade except perhaps for the wood interior. One cabinet line here is trying to sell me on the fact that their cabs have plywood SIDES - though the rest of it is particle board.

Actually I found out that even Wood Mode uses particle board for the boxes if you use their frameless option.

I got my cabinets from Scherr's Custom cabinets. I paid for the upgrade to plywood construction, and am happy that I did.
The exteriors of my cabinets are quartersawn red oak; the interiors are maple veneer. However on the pieces of the cabinets that are exposed ends, they didn't have quartersawn oak veneer faced 3/4" plywood. Therefore those pieces are 3/4" MDF, faced with QS oak veneer (including the toekick boards). I was somewhat unhappy about this at first especially about the toe kick boards which will occasionally get wet from spills, and mopping, but it has not been a problem yet.

-Bob

My research indicated that veneers actually adhere better to MDF and furniture grade particle board because the surface is more uniform than plywood and more dimensionally stable. I much prefer a melamine interior (not that flimsy paper with wood grain designs on it) to poly coated ply or veneered wood interiors (as long as the cabs are edge banded to match the doors and open cabinets are finished to match the doors).

You want to know the ANSI rating of the paticleboard being used (for one thing this assures you it was made in NA).

Here is a link that might be useful: ANSI ratings

My understanding is that you actually want MDF for frameless, as it's dimensionally more stable than plywood, and cuts to a better straight line. Remember that the box itself acts as the frame, rather than the front, so you need material that will hold true angles.

MDF is also much heavier than plywood, which is why many installers and custom cabinet makers will push for plywood...easier to lift and install. I helped to lift and install them, so I can attest from personal experience how heavy those MDF boxes were.

We went with a medium high end frameless cabinet line and they told me not to upgrade to the plywood boxes, even though they would do it if requested. Not worth the extra money, they said. This directly from the salesman.

I did get cherry plywood for the exposed end pieces, and opted for melamine interior for ease of cleaning.

And for all of those who worry about sink base cabinets being in MDF and leaks, we did have a big leak right after the renovation and I didn't notice it for the several days. No damage to the cabinet and no swelling of the wood. Another advantage of the melamine interior and of sealing the inside edges with waterproof caulk, as you're supposed to do.