Cabinet Back Options
Half-inch plywood, or quarter-inch plywood and cleats? March 17, 2005
I build face frame cabinets with 3/4 inch veneer plywood and I am considering using 1/2 inch backs and eliminating the cleats that I use with the 1/4 backs. Are there any opinions on this process?
You don't designate if these are uppers/lowers. Regardless, I use 1/2 for both - just plain stronger.
I have done both. On small jobs, it usually depends what I have lying around. Inevitably we end up with a lot of excess material from our backs. We usually decide what we want excess of lying around. We use 1/4" for drawer bottoms so we often stick with those. I'm sure you'll hear bonified arguments for both. If I could order just the right amount of material and cost was not an issue, I would go with 1/2" all the time. But 1/2" pfin runs us $80/sheet, compared to 1/4", which we can get for $38. The extra 5 to 10 minutes for the cleats is worth it in that scenario.
$80 for 1/2" prefinish? Highway robbery. West Coast we're about $45-$55 for 1/2 or 3/4, $27-30 for 1/4.
I outsource drawers, so don't have any use for the 1/4 or 1/2 drop off from cabinet backs. I've gone to 3/4 material for everything, including backs. That way, I run everything from the same unit of material. Waste has dropped dramatically. There's no concern about the case holding together (using 1 1/2" staples, then Confirmats), and racking the case takes a ton of effort!
Material cost savings in the scenario would not amount to much over the course of a full set of cabinets. The real issue here is the amount of time involved to build the box. If you are going to be planting the 1/2" backs on with screws versus a dadoed and nailed 1/4" back, the nailed version is faster. Any time you have to pick up a screw gun to use with loose screws, it will cost time compared to using nails. In our shop we used to plant solid 3/4" backs on with screws. We switched to 1/4" backs dadoed in with 1/2" nailers behind the back. The backs and nailers are glued and nailed in place. What we found is that the box is just as strong as before, is easier to install because the cabinets don't weigh a ton and are assembled much faster than with the screws. That said, we did a similar study into the way we built the bottom of base cabinets. We were using leg levelers to save on material costs and found that it took way longer than just notching a kick. The small cost that we saved in case material was more than offset in the extra amount of time it took to install the feet. With a few tweaks like this and a few pieces of inexpensive equipment, we increased our production by 50%.
Good question. I am reevaluating the way we build. How are you guys attaching the 1/2" backs? If you plant, what are you using to secure - staples, screws, glue? Do you rabbet and staple? And how does this differ for base units?
I know I am probably the odd one here, but I use 5/8 for everything - sides, bottoms, backs, tops. Cuts way down on waste and is not as heavy as 3/4 all around.
Whatever I use for my gables, etc., I use for my backs. I don't dado anything and I don't use glue! Staples and confirmat only. I'm not high production, so I like the fact that I can cut a cabinet down easily on site or even knock it apart and put it back together easily.
1/4" stapled on base backs, 1/2" stapled/screwed on upper backs. I use an autofeed Senco collated screw gun - costs the same as a good cordless, but is a whole world faster than confirmats or loose screws.
I use a 4 3/4" nailer on bases (same rips use for ladder bases), and back is cut 28" so drops are already close to drawer bottom size (21 1/2). 1/2" drops are sold to two local birdhouse/feeder makers. Solid scraps are bundled and sold as kindling for $2 each. But the shop's still a mess!
Comment from contributor J:
I know this method may be slower, but my first concern is quality and longevity in my cabinets. I use glue on everything, as screws, nails, and even staples can come loose over years of seasonal movement. I use only 3/4" plywood for the case and 1/2" ply for the backs. I set my tablesaw up with a 1/4" dado and dado out 1/4" deep 1/2" in from the back edge. After I cut all my dados on the cabinet sides, I adjust the height and fence and rabbet the 1/2" backs. The back is then glued in place during assembly and provides an exceptionally strong joint that cannot fail without the entire cabinet coming apart. Does it take longer? Yes, but my clients know what they are getting and will pay for quality.