What Thickness of Material for Cabinet Backs?

Cabinetmakers discuss whether they use 3/4-inch, 1/2-inch, or 1/4-inch plywood for cabinet backs, and the reasoning behind their preferences. July 11, 2013

We ran into an issue with cabinet backs. I had a client recently that went to 3/4" Backs with 3/4" nailers and that messed up the interior clearance, so we try not to go over 1" total back thickness. We like to do a 1/2" captured back with a 1/2" nailer. For us this has been a standard that we try to carry over to our millwork and casework shop drawings. Some shops will only do 1/4" backs with a 3/4" nailer and I have seen the GC complain that the backs look wavy. We find the more solid 1/2" looks better after you drill out for the water supply and drain or any other penetration through the back of the cabinet. What is your shopís preferred standard for cabinet backs?

Forum Responses
(Cabinetmaking Forum)
From contributor K:
We use 1/2" backs. They sit in rabbets in the gables and the deck and are screwed into the top. We glue and shoot staples through the gables, and glue and shoot staples through the backs into the deck. Weíve never had a problem. We do a bunch of inset so we use 12" gables (sheet goods are oversizes) and that gives us 11 1/2" on the inside for clearance.

From contributor M:
I build my upper cabinets with a 3/4" back attached with blind dados on two edges (CNC). I also screw the back securely to the box with 2" Spax screws. A nailer is really going to be overkill with a 3/4" back. I can't think of any reason to do this. For lower cabinets I use a 1/4" back set in a rebate. The nailer is inset so that it is flush with the inside edge of the rebate.

I like to measure my clients stuff to make sure it will fit in the new uppers! They often have plates, etc. that are too big and preventing doors from closing, especially in compact kitchens in apartments and condos. I like to squeeze in some additional depth whenever possible.

From contributor G:
1/2" back with lots of 1 1/4" staples.

From contributor F:
1/2" backs in grooves 1/2" in from the back edge. Itís easiest for construction as the backs, bottoms, and tops are all same length and the back serves as the nailer. I'll make my insets slightly deeper than overlays to accommodate for interior depth problems. If it makes you feel better, you can fill the 1/2" void in the back with filler for a nailer.

From contributor C:
1/2" prefinished maple screwed on with #8x 1 1/2" screws 6" o.c. plus/minus. No dadoes, no rabbet, just screwed on. If itís an end cabinet, the exposed end gets a rabbet 1/2" deep plus 1/8 or so for scribe fit depending how much the wall is out of plumb.

From contributor F:
I guess that most of you are using applied end panels since you're screwing the backs all the way around. I use integral ends with the 1/2" groove. It works on both exposed and non-exposed sides. The only issue is keeping the interior of the cabinet consistent in which case you can nail a quarter inch to the interior side.

From contributor G:
On uppers I put screws along with the 1 1/4" staples on the tops and bottoms. I also put a screw in the spot where it will be screwed to the wall into the stud. Of course this is done during the install. I don't put screws into the lowers except during install, same as the uppers.

From contributor S:
3/4 backs hands down, glue and screwed. No nailers.

From contributor C:
I'm with Contributor C - 3/4 backs, 3/4 sides and bottoms. The bottoms are set in a 1/4 deep dado and the sides have a 1/4 deep rabbit to drop the back in and then itís all glue and screws. No chipboard or melamine, all plywood!

From contributor F:
I'm guessing the folks that use 3/4" backs are still pretty young or have young installers. It seems like extreme overkill to me and a shortening of your career lifting those boxes. I'm just curious why you would want to use 3/4"? Is it just material consolidation? Not knocking what youíre doing I just don't get it.

From contributor H:
For me a 3/4" back is just plain easier. Sure if the cabinet is narrow it seems like overkill but try a 36" wide base cabinet with four drawers or a 36" pantry cabinet. a 3/4" back makes attaching the finished bar face easier when I build an island or bar cabinet. I have a contractor that likes 18" deep x 60" tall upper cabinets (don't ask me why) and I don't have to worry about hanging them with a 3/4" back holding it together. If I didn't have to install I might go back to 1/4" backs as they are simpler to construct.

From contributor U:
I'm with Contributor F on not getting it. I use 1/2'' for everything except the shelves, which are 3/4''. I do mine the way Contributor G does. I also found out a long time ago that cabinet customers will not share your enthusiasm about rabbets and dados, as long as the box holds together then they don't care how they are constructed. So I build mine the simplest way I know how as long as it is solid. I spend my time on a good design and seeing where I can fancy it up without breaking the bank.

From contributor S:
Yes on material consolidation but I have a 14"D cab, finished interiors. Having no nailers eliminates a few steps and gives me a nice clean look. The cabinet back gets edgebanded on the bottom and you have a nice clean box. I found using 1/2 that I had tons of scrap all the time and even using 1/2" drawer bottoms I could not use it up so I went to 3/4 backs. Everything gets end panels so I just glue and screw everything to the back of the carcase.

From contributor D:
We build our home office cabinets and garage cabinets with 3/4" backs. We used to use 1/4" but switched about a year ago. The only downside is that the cabinet is heavier. We do a Euro style cabinet and do matching melamine interiors and offer it in 16 colors. The cost difference was negligible, with some colors costing more in 1/4" than in 3/4". Then figure in all the waste that we couldn't use and the racks that we were storing scrap in. Add on to that that we were cutting nailers, etc. The 3/4" just made sense for us in our market. We get a much stronger cabinet, virtually no waste, and lower inventory with fewer parts to handle.