Hello All,
I’m installing a French cleat for a cabinet. Cabinet dimensions are 35″wide x 17″ tall x 15″ deep. Baltic birch over plywood (hey, that’s plywood on plywood)
The cabinet will weight perhaps 70 pounds loaded.
The cleat on the wall will be 3/4″ x 3″ x 35″, oak, Tap-Conned into concrete.
The piece on the cabinet itself is where I have a question. It too will be about 35″ long, but can I use 23/32″ Baltic birch for that?
I could use the same dimension oak as is on the wall, but then I thought, plywood will be stronger. But then I thought, no, plywood might shear where the layers are glued. Then I thought, no you’re overthinking again. Better to ask.
I’m not concerned about the French cleat where it’s joined to the cabinet, that will hold fast. Just the wood comprising the cleat itself.
Any thoughts?
-jonnieboy
Replies
I only use a french cleat as a means of hanging an empty cabinet. Once hung you screw through the back of the cabinet through the cleat into a stud. The cleat & back must be structurally sound to the cabinet.
jonnie,
There are several companies who make what are called Z Clips, Lee Valley being one http://www.leevalley.com/hardware/page.aspx?c=2&p=41869&cat=3,41306,41308
I've used them often and make them out of ¾" stabile solid wood; haven't used plywood but have seen many references to using it. I should think either one would work well. Here's Tom Hintz site that explains them a bit more. I haven't tried the recessed one.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I contacted Lee Valley to get some information about there Z-Clips and got the following response."We have been asked this question before and the following is the manufacturers response concerning the weight the Z-Clips (# 00S18xx) will hold:The MONARCH Z-CLIP is extruded from billit aluminum alloy 6063-T6. By itself the MONARCH Z-CLIP will withstand thousands of pounds of stress, both compressive and tensile. The concern should not be with the structural integrity of the clip, but with integrity of the substraint you are screwing into and the hardware you are using. Taking four #8 x 3/4" pan head screws, and two MF625 - 1 1/2" Z-CLIPS, we mounted the Z-CLIPS to two 2x4s and connected them both together. We put a load on the assembly trying to break the connection. It failed at 475lbs, the screws pulled out of the wood and NO VISIBLE DAMAGE WAS NOTED TO THE Z-CLIPS.”I hope this helps some.Chuck
WoodLess,
Thanks for the info on Z-Clips!
--jonnieboy
The Baltic Birch will be fine for the cleat. The load is distributed across all of the plies so there are no forces that should cause it to shear between the plies and the shear strength of the glue line is probably better than the shear strength of solid wood.
Ideally the top edge of the cleat on the cabinet will bear against the overhanging top of the cabinet, and in addition to glue, use screws through the back, from inside the cabinet, to attach the cleat to the cabinet's back.
Shop Manager for FWW Magazine, 1998 to 2007
John,
Excellent. Thanks John.
As I read on Hintz's page, their main concern seems to be with the attachments to the wall, and how stud widths limit that. Because I'm using Tap-Cons I don't foresee any problems with that aspect. I can use far more anchors than 16" on center as with studs.
I cut (dadoed?) a 4" channel into the back of the cabinet for the cleat to screw onto. It connects at the right, left and middle vertical walls. I think I'll change that to get the cleat right up under the top of the cabinet. as you suggest. That makes more sense structurally.
Thanks!
--jonnieboy
I'd make the cleats -- both halves -- from wood, not plywood.
And I'd want to look through the website for tapcons, to learn about their strength against pullout. I don't think I'd be concerned about shear -- but pullout would worry me.
But as others have noted, the cleat is just an installation aide. If you plan to use anchors for the installation screws -- through the cabinet mounting rail, and into the anchors in the concrete -- you're good.
I won't be laughing at the lies when I'm gone,
And I can't question how or when or why when I'm gone;
I can't live proud enough to die when I'm gone,
So I guess I'll have to do it while I'm here. (Phil Ochs)
I'd be comfortable with the tapcons - assuming the cabinet will be supported against the wall at the bottom, it seems like it should be only shear.
Never thought about using ply for one cleat, but John W explained that well. When I use french cleats, I take a hardwood board, and make the bevel cut in the approx. middle of the board, so that the angles are identical, then I use half on the wall, and half on the cabinet.
Just me - but I'd take that 3/4" x 3" piece of oak and bevel-cut it in the middle @ 45*. Short dim will be about 1" (long dim about 1-3/4") - I would be comfortable with that arrangement - plenty of room to countersink for tapcon head, and strength is not an issue IMO if you anchor at 3 or 4 places.
Edited 10/14/2009 12:43 pm ET by Spotcheck
I'm still worried about the tapcons.If you support the cabinet from the bottom, the tapcons for those bottom supports will be "in shear". But whatever is holding the top of the cabinet to the wall, will be "in pullout".And the pullout force can actually be quite strong. You're talking about a 70 or 80 pound cabinet, with perhaps a couple of hundred pounds of stuff inside. With that kind of weight in leverage, pullout force might be hundreds of pounds per screw.That doesn't make the idea a bad one. But as I mentioned earlier, I'd be looking for engineering data from Tapcon.
I won't be laughing at the lies when I'm gone,
And I can't question how or when or why when I'm gone;
I can't live proud enough to die when I'm gone,
So I guess I'll have to do it while I'm here. (Phil Ochs)
Shouldn't one also consider the quality of the concrete? There are various grades and the lower ones are quite "crumbly". After all concrete is usually graded for compression strength. Tapcons in "pullout" mode are applying a shear stress to the threads cut in the concrete.I'd never even heard of tapcons until a few minutes ago but personally I would not want to use them.Wouldn't 8 x 80 mm ( or even 10 x 100) Fischer screws be a better bet? On paper you're relying on the plastic sleeve but in practice the only failure I've ever had was when I used what must have been a cheap copy. The plastic actually reacted with the stone (limestone) and shrank. My mother's crockery was reduced by about 5% but 25 years later the survivors are still in service.
I've used Tapcon for many years in all types of applications - none in kitchen cabinets per se, but in other analogous applications that put more on them that the cabinets will. For example, the galvanized adjustable lumber racks with 16" arms, 48" tall, verticals 16" - 17" OC, mounted on the cinderblock wall over the CMS, loaded TO THE BRIM with QSWO and RO, overall length 14'. Over 500 BF at times - prolly 2,000 lb plus the weight of the storage racks themselves. And, I didn't gently set down a can of soup on the top shelf - I sorta half-heaved a chunk of 5/4 x 10" x 14' lumber up there 8' high. I made sure to drive them into the block, not the mortar seam - no science behind that decision - I just was more comfortable with the cinderblocks than the mortar in a 75+ yr old house.
I like the Tapcon because they are easy to install, and the holes are small - not that I cared about the size of holes in the wall, just that small holes are easier to punch than big holes. Also - I don't need a large hole in the cleat (or whatever).
I assure you, for the first few minutes after I had learned about them, my response was "you are kidding me". But my friend who was with me and pointed them out on the shelf (lifetime career in concrete and related products) said "Aww, just shuddup and buy them already". So I did.
My point - there are a lot of fasteners that will work. I am sure there are fasteners I have never heard of that will work. I have complete confidence in using the Tapcon for an application like that. But - they ain't my cabinets and it ain't my kitchen. Just offering my personal experience to the OP.
Hi Dave,
I was a bit wary of Tapcons (I was misspelling it Tap-Con) at first myself. I've used Redheads and lead anchors. The lead anchors a LOT. You get a feel for what's solid in a wall. These Tapcons are solid. They self-tap into the concrete. I tried them on a paint shelf first, and now I have no qualms about using them.
As far as load ratings, I went to their website (ITW) and of course they only have it in pi-r-squared terminology that I don't understand. They might be telling me, but I can't understand it.
I believe I saw on the display at the store that the 1/4" screws I bought are good for either 150 or 220 pounds. Not sure which, but the cabinet will weigh maybe half that fully loaded so I wasn't too worried.
The concrete is about 7 years old, and hard as a, well, a rock.
Also, in Ernest Joyce's Encyclopedia of Furniture Making, he illustrates a French cleat, or what he terms a "bevelled rail." Speaking in general terms he says they will support "considerable "weight. He goes on to caution that if the carcase might want to sag, it should be reinforced with an inner rail, or even an "under-batten" screwed to the wall (page 432).
Something worth noting is that in neither the illustration nor the text does he mention screwing through the cabinet and into the cleat. I hadn't planned on doing so, and you guys started scaring me (just in time for Halloween). I'm certainly not saying this isn't a safer way to go, I'm sure you guys with experience know more about it than I do. It surprised me is all, because I didn't remember reading anything about that. Then again, you can't get all your knowledge from books.
I can't remember where I just read of someone saying don't drill holes in the wall every time you want to hang a cabinet, install French cleats around the shop and you can change cabinet locations at will. Something like that. That's what I was reading when I made the decision to use lots of them. French cleats everywhere! French cleats for everyone!
This addresses more than what you brought up, but another reply mentioned some of these things. Thought I'd try to respond to as much as possible.
--jonnieboy
Personally I don't see the need to screw the cabinet into the wall. The cleat will take the weight and distribute it better anyway.My concerns rests entirely with the concrete. It does not like shear which is why it has to be reinforced with steel.
AS long as the hole for the tapcon is the correct size, and all dust is cleaned out of the hole, a tapcon will stay put. Be sure to leave the ho;e a little deeper than the tapcon you are using. If it "bottoms out" , it will start to "strip" out the sides of the hole. When you can tapcon forms into existing concrete walls and then pour a new wall using those forms, that should say a lot about how much these little blue screws can hold. Right drill bit size? The larger boxes of these screws come with both a drill biy of the right size AND length, plus a "driver" to drive the screws in place. Nice." Although I have the right to remain stupid, I try not to abuse that right"
"........If it "bottoms out" , it will start to "strip" out the sides of the hole........."
Heh-heh-heh. Voice of experience speaks. I certainly know that feeling.
My $.02...............Use an impact driver for the Tapcons, you won't strip near as many as with a standard drill/driver. Matching the drill bit size to the correct Tapcon is critical. I see them every day in my business and, if installed correctly, are extremely strong. I've used them at my store for shelving holding up boxes of paper, probably much heavier than any wood I would store on them.The correct term for the "pullout" that is being discussed here is "withdrawal". Due to that thing called gravity, all loads are vertical. It's when we extend the point outwards, i.e., a french cleat, that we induce the dreaded pivot. Stuff still wants to go straight down, but it's hindered by the fastener itself. If the fastener fails and goes into withdrawal (!), the gravity/load/vertical thing tends to form a slight curve. All things being equal, if you built a cabinet, say 24" tall, and loaded the top 6" with 100#, would it want to "withdraw" more than if you only loaded the bottom 6" with the same 100#?This is fun.Rich
Rich - thanks for install tip re: impact. Would my corded hammer drill qualify? "Impact" to me is what the guys in the shop use on my car's wheel lugnuts.
On loading question:
"All things being equal, if you built a cabinet, say 24" tall, and loaded the top 6" with 100#, would it want to "withdraw" more than if you only loaded the bottom 6" with the same 100#?"
Absolutely. Think of it this way. Stand looking at the side/end of the cabinet, and draw a line from the anchor to the point of load. Move that load lower, and the angle of the line changes - that vector shows more of the load is going to "vertical". Now imagine your shelves are of infinite height. Put the load on the bottom shelf, draw that line. The line is now essentially vertical - the load is going straight down.
Hammer drill, yes. Not sure why I said impact, not enough coffee yet, I guess.........Agree with your treatise, mine was more of a rhetorical/let's-talk-about-this hypothesis, but yours is a good visual. Rich
Rich ,
I know that if I load my bank account with $100, even if I do so with great care, it wants to withdraw almost immediately.
Hey, you say use a hammer drill for installing the Tapcons? Not impact driver? Are you sure you don't have that backwards?
--jonnie
No, hammer drill has always worked for me, never tried an impact driver. Those few Tapcons that I attempted without the hammer drill failed miserably...........And I've always had better luck drilling in the mortar joint, if masonry, than the masonry itself, altho' I've not attempted anything in something really old. RichLike this one.......................http://www.dewalt.com/us/products/tool_detail.asp?productID=22917
Edited 10/15/2009 8:39 am ET by Richard Jones
Richard,
Well this must be my lucky day. I already have a hammer drill, but not an impact driver. I'll try it out as soon as the house wakes up.
Thanks.
-Jon
Tapcons with the enclosed drill bit has worked for me on MANY projects! And then some, I haVE NOTHING BAD TO SAY about Tapcons!
The reason I use french cleats for cabinets, etc is simply for the ease of installation. I'm a whole lot better at hanging a cleat level than I am at hanging a cabinet level. Plus - leave some gaps side-to-side, and the cabinet always ends up in the correct spot.
And I agree that it isn't necessary to fire fasteners thru the cabinet into the cleat half that is already attached to the wall. (but the first time - whew - the owner of that house must look at the back of the kitchen cabinets and wonder if someone was getting paid by the screw :)).
But - I don't really use them much in the workshop - the primary tool wall is over the back bench, within arms reach from the main workbench, and is covered with 1/2" ply. just make small brackets as/when required to hang hammers, saws, chisels, etc and fire in a couple woodscrews. But - I DO have sheves and drawers in nearly every conceivable nook and cranny - sometimes it seems like I notice a small open space somewhere and build a shelf or drawer just to fill it - nature abhoring a vacuum, maybe.
jonnie,
Here's some pics from the woodshop. The cleats can also provide shelves for storing saws also. You can also add more just by adding same thickness boards on the cabinet back.
View Image
Yeah I know, the DTs are a bit rough. First ones I had hand cut at the time.
I also hang racks for files and rasps and place them in the tool trough for easy access when using them. I've thought of adding more on the wall(s) and making additionall racks. Makes it easy to pack them when traveling too.
View Image
The whole thing was made from 3/8" prefinished drawer sides from Ethan Allen. They used to give me their seconds but have since closed shop. Sigh.
View Image
In the trough.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,
These are a great idea. I'd never thought of French cleats for something smaller like this.
It gives me an idea. One could actually put cleats inside a tool cabinet. The tools can be taken out on their racks and they'll have a handy place to keep them organized while on the bench.
One could make a simple way to fasten them down if the cabinet is going to be moved. Many tool cabinets are too big to be moved around very often anyway. The tools go into a smaller portable box or boxes. Just thinking out loud.
That's a good system, Bob. Thanks!
--jonnieboy
Bob,
I meant to add, the picture with the nice new dovetail saw in back of the French cleat, then the file next to the red one, with a handle dating back to ancient Greece. I was struck by the contrast. Pretty nice. Gotta love both, right?
--jonnieboy
jonnie,
I made the chisel rack a bit different, sans french cleat. I opted to allow for it to lean out of the door when I'm using the chisels. Just flip out the wedge at the end and it flops out onto the stop.
View Image
If you want the closer to where you're working on the bench.
View Image
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,
Yeah! Just like I was thinking, except you had done it before I thought it. Like I said, those are great idea.
Man, pretty soon it'll be time to build my own tool cabinet. That will be fun. I already have the space cleared out where it's going to sit.
Thanks, Bob.
--jonnieboy
Bob,
I got some guy online trying to buy my RAS. I think he knows the guys who 'visited' your house (on their way to the pawnshop).
All I have to do is send this guy all my personal information and he's going to have his movers pick it the saw. Ooh, hey, "Tito," I've never heard of that one before.
--jonnieboy
Tapcons are a metal screw that holds extremely well. I do not have any data on pullout or any thing else except experience using them. I believe if you get occasion to use them you will change your mind on tapcons. I had to remove a 16'-0" 2x4 plate that was installed incorrectly. There were tapcons holding it on 2'-0 centers. I tried to unscrew them but they were driven flush with the 2x4. I wound up using a stripping bar .The 2x4 pulled right thru the tapcons,I then could unscrew them.
Never heard of a fisher screw?
mike
Fischer Screws are a Screw and a plastic wall plug where you drill the same diameter hole through the workpiece and the wall. Then push in the screw and tighten.Like these: http://www.anzor.co.nz/?t=24&PCT1=51I do not have anything against tapcons. My wary approach is due to the fact that unless I have seen the concrete test certificates I cannot trust the concrete.
YesMaam,
I happened to be at the hardware store this evening. I wnent by the Tapcon display and jotted down the info for 1/4" Tapcons.
These figures are for 4000 psi concrete. I have no idea how that compares to a typical home foundation wall.
Pullout:
If drilled to an inch of depth: 800 #
If drilled 1-1/4" depth: 1340#
Shear:
If drilled to 1" depth: 1360 #
If drilled to 1-1/4" depth: 1370#
--jonnieboy
That's much more impressive than I thought it would be, and obviously strong enough to hang cabinets.
I won't be laughing at the lies when I'm gone,
And I can't question how or when or why when I'm gone;
I can't live proud enough to die when I'm gone,
So I guess I'll have to do it while I'm here. (Phil Ochs)
Yeah, it surprised me too. Good thing though, the cabinets are heavier than I thought they were going to be. Oops.
--jonnieboy
Please correct me if I'm wrong but don't french cleats somehow cause the weight of the cabinet to be downward as opposed to outward?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Yeah, I'd think so - to a fair degree. The angle of the cleat is moving the weight down and back to the wall. If there is a 3/4" cleat at the top, I always attach a 3/4" strip to the back of the cabinet near the bottom - just to keep things leveled out. Having said all that, if we got a mechanical engineer on the task, we would find that a load near the front edge (away from the wall) would still exert "pull" away from the wall.
If it was simply a beam sticking out of the wall, with beam weight = 0, and the beam was 2' long, then a 100# point load at the very end of the beam would exert 2*100 = 200 ft-lb of torque (or bending moment) at the wall. Not enough of my engine-school classes from 137 years ago stuck with me to be able to do anything with the impact of the cleat design, the edges of the cabinet pressing against the wall, the support provided by my strip at the bottom, etc. These surfaces are taking load from the 100#, there's vectors and actual mathematics involved here. With the attachment point theoretically where the top shelf meets the wall, then the same 100 lb point load at the front edge of a shelf one foot below would be less than 200 ft-lb because more is being transferred to the wall ....................and I am lost now.
Edited 10/14/2009 10:22 pm ET by Spotcheck
An old lady walks into the doctors office and proclaims to have pharted several times without he noticing it and asks the doctor for help as it is quite embarassing. He gives her some pills and asks her to come back in a week.
A week later the lady returns and complains to the doctor that she still pharts and can't hear them, but they smell terrible.
The doctor says, "Well, now that you can smell we'll start working on your hearing.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
<grin>
I went through this about 2 years ago when I had to design a "special" set of pipe brackets.Take a cabinet, any cabinet, and hang it from a wall. You can treat the weight as being all at the centre of gravity, which is approximately in the centre of the cabinet and exerting a force downwards.It is trying to pivot around the bottom back edge. So you have a pullout component on the screws at the top. MOST of the force is shear and downwards but some of it is outwards.If you support the base of the cupboard you will reduce or even eliminate the downward shear force but will not effect the pullout.Incidentally a threaded rod must have its shear resisting rating downgraded by at least 20% compared to a plain rod.
Bob,From an engineering standpoint, once the two cleat halves are meshed the forces on the fasteners and glue joints are identical to the forces on a single board as wide as the two combined boards with the fasteners and glue joints in the same location.John White
Shop Manager for FWW Magazine, 1998 to 2007
It is usually wise, and in earthquake prone areas very wise, to use a few screws to tie the hung cabinet to the wall cleat so that the cabinet can't jump off the cleat if things start shaking.John White
Shop Manager for FWW Magazine, 1998 to 2007
I can not agree more, an earthquake is an interesting experience.If there is even the slightest chance of an earthquake, go a little further and securely attach any and all cabinets to the wall.I was at ground zero on a 4.7 (1/2 mile from the epicenter) and was amazed to see things fly 5 feet into a room from the bookcases and shelves. Not only did the building shake, it seemed to hop too.The free standing bookcases were anchored to the wall, thankfully they remained upright, but file cabinets shifted enough to crack the cinder block and brick walls; equipment tore out of the lift slab walls in the shop (incorrect/dangerous installation) and the CNC bed did a "slight" 6 degree off-center move (the bed was replaced due to the slight dip, probably caused by the hopping).However, not counting the heart and nerve stress test, nobody was hurt but the office peeps would not have fared well if someone hadn't done a little retro and put those few screws in. All of this was just from a small 4.7, can't wait to see what the "Big One" brings. :)
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