Expert: Jamie Yocono - 8/5/2007

Question
Hello!
We want to install a counter top (from ikea, 96 inches long 26" deep weighs 46 kg) onto a wall with some heavy duty legs from ikea at the front but wonder how much support it needs ( I'm sure a lot) at the back...wondering if we get a metal L shaped brackets (some come with the leg) and put those into the studs all along the piece whether this will be enough support....supposedly these legs, 2 of them with the small metal L support brackets are enough to hold up a 26 kg. table....Or should we do a ledger board....I also have some particle board V brackets from my mom's house that previously supported a kitchen counter (free standing).  We're trying to get it as sleek and simple as possible so the kids can all be at the table at the same time doing homework...
If you could even direct us to where to find this info out about how to calculate how much and what type of support are necessary given the weight of the material, the depth, and the use....
Thanks in advance for your help...!
C. Ford

Answer
Hi Cynthia,

Sorry it took me a couple of says to get this answer to you, I read your question and needed a little time to come up with a cohesive answer. The answer to your question is sort of long, and multidimensional. But- it sounds like what you're trying to do is perfectly "doable" and you shouldn't have too much trouble making this work.

There's a pretty interesting website that will calculate the sag on any horizontal material, so this site might help you with figuring out what is going to happen with your counter top.  The web address to that site is:

http://www.woodbin.com/calcs/sagulator.htm

I love that name, The Sagulator, by the way. Someone had a sense of humor when developing that page, and it's VERY handy to have for reference.

That said, you're wondering about supporting the countertop, mostly along the front edge.  I will try to help and not give you too much to worry about.

OK, usually, a countertop is made of medium density fiberboard (MDF) for a core, and then plastic laminate on the top surface and edges. Without seeing the actual Ikea product, countertops are made with 3/4" thick material, but the perimeter is actually a double layer of the MDF, so it looks like it's 1 1/2" thick, but it's not really. Just on the edges, which give it some support.  So some parts of the countertop are 3/4" thick, and other's are 1 1/2" thick. With me so far?

If you use some sort of metal angle bracket along the back edge of the countertop, where it meets the wall, that is perfect for supporting that back edge. A ledger board would work, too. The idea is that you need to support all along that long edge. But the long front edge is where you're going to have some support problems. Even if you put legs every 2 feet (which you wouldn't, for aesthetics) it wouldn't be enough support. See, MDF isn't very strong at all, and even a 2 foot span can sag. So what you probably need to do is attach some sort of under support, like an apron, that will support the shelf in front, like the angle bracket (or ledger strip) does on the back.

Something about aprons- imagine a 2 x 4 laid flat. If you put a block at each end of an 8 foot 2 x 4, and stepped in the middle, where it's unsupported, it will flex. But turn that 2 x 4 on edge, where it's now 3 1/2" tall, and step on that skinny edge; there's no way you can flex it. See, wood is stronger in one direction that the other. So even if you use a rather small piece of wood, like a 1 x 2, if you turn it on it's edge and attach it to the underside of that front edge, it will probably support that front edge and keep it from sagging. Hope that made sense!

I think I understand the sleek look you are trying to achieve; try looking at this website and look at some of the interesting hardware they offer:  http://www.mockett.com

OK, I think this is enough to get you started, write back if you need more help, or have any more questions after reading this. An apron under the front edge is the key to everything you want to achieve. Good luck,

Jamie Yocono
Wood It Is! Custom Cabinetry
Las Vegas, NV
www.wooditis.com