Cabinet shelf stiffener ideas?

buening · Nov 10, 2011

I'm looking for other ideas to stiffen up shelving. I'm building cabinets and on one cabinet I have shelving that is roughly 47" clear span and 24" deep that uses 3/4" oak plywood for the shelf. The shelving is supported on the back and sides by shelf clips, but the front edge still needs a stiffener/brace to prevent shelf sag due to the longer span. I stuck them in the cabinet temporarily while I built another cabinet and they sagged slightly under their own weight.

The common way for stiffening a shelf is a hardwood strip along the front edge that is a 1x2 or so. I'm looking for a solution that is low profile yet strong enough to stiffen the shelf. What I've come up with is to use a piece of angle iron, in either 1"x1"x1/8" or 1"x1"x1/4", screwed into the shelf along the front and from the bottom in alternating fashion. With the 1/4" thick legs, it will fit flush top and bottom of the shelf as long as I router the bottom edge of the shelf. With the 1/8" thick leg, I'll have a small gap between the shelf and the leg. See the two pics I have attached for those two. The 1/4" thick angle iron is $1.30/ft whereas a 1"x2" oak board is a hair over a dollar a foot, so they are priced similar.

Does anyone have any other DIY ideas? I've found a few online (see below), but they are mostly aluminum and am not sure how much it will really help. They are also more expensive.

Thoughts, suggestions, comments? No suggestions that block the shelf opening like a vertical piece from bottom to top of the cabinet, as I want to keep the entire shelf open.

Brad54 · Nov 10, 2011

I really like that first aluminum extrusion.

A piece of aluminum angle would also work--don't know the price though.

Aluminum is easier to work with, and if you scuff it with some scotchbrite, it looks good.

-Brad

buening · Nov 10, 2011

I'm just worried that since aluminum is weaker than steel and it looks pretty thin in the picture, that it'd stiffen it up even less than what the hardwood piece would. That first one is also about $3.50/ft not including shipping. I'll look into the aluminum angle to see what it costs. I'm hoping for a local source of whatever I use, as I'll be needing about 30' total of whatever I use.

I just calculated the deflection of the shelf with only assuming the angle (neglecting stiffness of the plywood). With a constant load across the shelf of 50 pounds per foot (200lb shelf rating), I'll get 1/4" max deflection with the 1/4" leg angle iron. Not too shabby.

Edit: Aluminum would result in about 3/4" deflection, triple that of the steel.

KenC · Nov 10, 2011

Most of the stiffness in the angle would come from the vertical portion. So, I would try one shelf with just a 1" wide piece of 1/8 or 3/16" steel strap. Attach from the front using countersunk head screws and epoxy. Or, just screws, I just like the solid bond due to the ply may delaminating from the load on the screws.

Jack Olsen · Nov 10, 2011

I know it's not what you're asking, but:

1) A 48" wide shelf is going to get messier, sooner, than two 24" wide shelves. Why not add an upright midway through and kill two birds with one stone?

2) A 1x2 -- even if it's Douglas Fir -- will add significant rigidity to the shelf, and it will look better than the edge of a sheet of plywood.

3) If none of that works for you, get an L-shaped shelf bracket and attach it either to the top or underside of the shelf at the midway point and paint to match.

MoonRise · Nov 10, 2011

You're asking a lot of a 3/4" plywood shelf to span 47" x 24" deep without some major edge reinforcement.

Just how much stuff/weight are you thinking of putting on that shelf?

Quick Google-fu turns up:

http://www.finewoodworking.com/SkillsAndTechniques/SkillsAndTechniquesArticle.aspx?id=28101

Whcih links to:

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

Also some general shelf guidelines:

http://www.woodworkingtips.com/etips/etip01.html

So yes, reinforce the front edge. (and make sure that the sides and back supports can actually support the weight of the loaded shelf. Cause that's a pretty big shelf you have listed.)

Although some steel angle-iron could work, IMHO I think it would be a bit 'ugly'.

Hmmm, how about some oak 1x at the front edge (hides the plywood edge-grain plys) and the steel angle-iron right behind that (vertical leg right behind the 1x oak edging). Attach well to both the shelf plywood and the 1x edging and it should stiffen up that shelf a lot while hiding the steel.

buening · Nov 10, 2011

KenC said:
Most of the stiffness in the angle would come from the vertical portion. So, I would try one shelf with just a 1" wide piece of 1/8 or 3/16" steel strap. Attach from the front using countersunk head screws and epoxy. Or, just screws, I just like the solid bond due to the ply may delaminating from the load on the screws.

Actually quite the contrary, the stiffness comes from the bottom leg. Think of an "I" beam, where the flanges of the beam get thicker and taller as the stiffness goes up. Good tip on the epoxy!

Jack Olsen said:
I know it's not what you're asking, but:

1) A 48" wide shelf is going to get messier, sooner, than two 24" wide shelves. Why not add an upright midway through and kill two birds with one stone?

2) A 1x2 -- even if it's Douglas Fir -- will add significant rigidity to the shelf, and it will look better than the edge of a sheet of plywood.

3) If none of that works for you, get an L-shaped shelf bracket and attach it either to the top or underside of the shelf at the midway point and paint to match.

Thanks for the tips Jack.

1) Yeah I know I have a challenge with these spans. I'm planning on storing some wide stuff in these cabinets (like 36" homemade sheet metal brake from angles), and having an upright just gets in the way.

2) Regardless they'll have something along the front edge to hide the plywood, whether it be a hardwood strip or a piece of angle iron. I was just testing the waters here to see if anyone else could come up with a more genius idea than what I am thinking.

3)Shelf heights are adjustable with countersunk pilaster strips like shown below, so those brackets probably won't fly

buening · Nov 10, 2011

MoonRise said:
You're asking a lot of a 3/4" plywood shelf to span 47" x 24" deep without some major edge reinforcement.

Just how much stuff/weight are you thinking of putting on that shelf?

Quick Google-fu turns up:

http://www.finewoodworking.com/SkillsAndTechniques/SkillsAndTechniquesArticle.aspx?id=28101

Whcih links to:

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

Also some general shelf guidelines:

http://www.woodworkingtips.com/etips/etip01.html

So yes, reinforce the front edge. (and make sure that the sides and back supports can actually support the weight of the loaded shelf. Cause that's a pretty big shelf you have listed.)

Although some steel angle-iron could work, IMHO I think it would be a bit 'ugly'.

Hmmm, how about some oak 1x at the front edge (hides the plywood edge-grain plys) and the steel angle-iron right behind that (vertical leg right behind the 1x oak edging). Attach well to both the shelf plywood and the 1x edging and it should stiffen up that shelf a lot while hiding the steel.

I completely forgot about the Sagulator. Interesting that it claims only 0.28" of sag with 50lb/ft loads (with 50% increase over time).

The aesthetics was another concern of mine and I agree. The shelves and angle would be painted all the same color (dark gray), and considered filling the radius gap between the angle and edge of shelf with bondo or something similar, although I'm not sure how long that would last if the shelf sags any.

Good idea with the angle behind the oak strip. This may be one of those things (in terms of aesthetics) that I do a sample shelf with the angle and get it all painted up, and if I don't like the look then I can add the oak strip in front of that.

boiler7904 · Nov 10, 2011

First two options that I think of are thicker shelves and small torsion boxes used as shelves.

kbs2244 · Nov 10, 2011

When I do garage or utility room shelves that they want 24 deep I use angle iron from old bed frames.
Even with 3/8 ply they will not sag.
I put it with the vertical pointing up.
It is easier and up get a “lip” to keep things from rolling off.
It may be a little “rough” for a piece of furniture though.

gauder the goof · Nov 10, 2011

How about routing a recess from below for a 1/8" rod to be epoxied in? Then you can always cut a strip of oak to fill the rest of the hole flush?

kv501 · Nov 10, 2011

I would face it in the manner Jack stated above (1 x 2) and add to it a 2x2 support in the middle going front to back. Tie it to the face board as well as the back (if there is one) and it will be hidden from the front.

I have a 10' workbench and that's what I did when I made the shelf on the bottom.

NUTTSGT · Nov 10, 2011

My cabinets have doors on the front and they are hinged from the center. The center board, which is a 2x4 is dado'ed to accept the shelf to hold it up in the center.

I know it's hard to see, but here is a picture.

rickb801 · Nov 10, 2011

I think that the angle behind the oak 1x would work great even with out the oak. Could even add a piece of angle in the middle of the shelf and in the back of the shelf as well, all mounted under the shelf with the L leg down. Would be super sturdy. I did a similar thing on a shelf 8 feet long and 24 inches wide but used 2 pieces of 1 inch square tube mounted near the front edge and rear edge of the shelf. It doesn't sag and the top is 7/16 OSB.

Nettace · Mar 12, 2014

I like the second aluminum extrusion with the taller front edge and darker finish. Could you tell me what web site it is available at?

Justanoldguy · Mar 12, 2014

buening said:
Good idea with the angle behind the oak strip. This may be one of those things (in terms of aesthetics) that I do a sample shelf with the angle and get it all painted up, and if I don't like the look then I can add the oak strip in front of that.

THat would be what I would do every time. :beer:

PCO6 · Mar 12, 2014

I have some shelves in my downstairs workshop that are about 46" long by 12" deep. They are melamine covered particle board ... so not that strong on their own. I screwed 2 lengths of drywall furring strips to the bottom of each shelf to strengthen them. They have been up for about 15 years and they have not sagged at all. They look a bit "industrial" from the underside which is fine by me. They add a bit of height to the shelf (3/4") which is also OK in my case.

I also have some shelves over my bench where I used a similar process. I ripped some 8' sheets of 1/4" plywood into 23.5" widths. Using screws I "sandwiched" 6 lengths of drywall furring strips between 2 sheets of plywood. They are unbelievably strong and light.

trainer · Mar 12, 2014

I'd put a piece of 1x2 (3/4 x 1.5" actual size) lumber on the front with 3/8 x 3/4 rabbit joint. Glue it on with carpenter's glue and your good to go.

If an extra 3/4" depth on the front edge of your shelf is a problem then you should re-t hink your design.

ddawg16 · Mar 12, 2014

I made my shelves out of Melamine.....which we know is not supper strong....but easy to clean.

I cut some 14g ss strips and screwed them to the rear of the shelf...and then screwed another 3/4" strip to the front.

Strouty · Mar 12, 2014

ddawg16 said:
I made my shelves out of Melamine.....which we know is not supper strong....but easy to clean.

I cut some 14g ss strips and screwed them to the rear of the shelf...and then screwed another 3/4" strip to the front.

So you phased your shelving with strips of stainless? Now you have two phase shelving. If you covered the top with stainless then you would have true 3 phase shelving.

(that was for ddawg16 and ddawg16 only, if you viewed this and you are not ddawg16, please unview it)

For the OP the I have made some shelves that had to carry serious weight, I ended up taking angle iron and putting them back to back, so the made a T but on its side. Then you get a shelf lip (as others have mentioned) and you have double the strength. If you don't want the lip you can use 3/4" angle iron and it won't mess with the edge at all.

joe_padavano · Mar 12, 2014

ddawg16 said:
I cut some 14g ss strips and screwed them to the rear of the shelf...and then screwed another 3/4" strip to the front.

The weak link in your design is the screws into the edge of the Melamine. Expect those to tear out if you put any weight on it, since the screws are what's transferring the stiffness from the metal to the shelf. The "C" sections shown at the start of this thread (lo those three years ago...) are designed like that for a reason - the load transfer doesn't rely on the screws.

ddawg16 · Mar 12, 2014

joe_padavano said:
The weak link in your design is the screws into the edge of the Melamine. Expect those to tear out if you put any weight on it, since the screws are what's transferring the stiffness from the metal to the shelf. The "C" sections shown at the start of this thread (lo those three years ago...) are designed like that for a reason - the load transfer doesn't rely on the screws.

Maybe.....but it's been working fine for the past 5 years

ddawg16 · Mar 12, 2014

Strouty said:
So you phased your shelving with strips of stainless? Now you have two phase shelving. If you covered the top with stainless then you would have true 3 phase shelving.

(that was for ddawg16 and ddawg16 only, if you viewed this and you are not ddawg16, please unview it)

.

It took me 4 phases to get it built....so I guess I have 4 phased shelving...

:beer:

buening · Mar 13, 2014

I had forgotten about this post, guess I should update it! For those that asked about where those aluminum stiffeners can be bought, I pulled the pics from the following two websites:

http://hangmanproducts.com/collections/cabinet-slatwall/shelving

http://www.eagleamerica.com/product/v400-1616/cabinet_tools_and_hardware

I ended up going with my original idea of angle iron screwed to the front of the shelf like in my drawings. I've sat on my 24" deep x 48" wide shelf with the stiffener and I don't think it even sagged. Built like a tank, just as I like

I will snap some pics over lunch today and post them up.

Fillys6 · Sep 25, 2014

buening said:
I ended up going with my original idea of angle iron screwed to the front of the shelf like in my drawings. I've sat on my 24" deep x 48" wide shelf with the stiffener and I don't think it even sagged. Built like a tank, just as I like

I will snap some pics over lunch today and post them up.

buening, did you get a chance to snap pics? I'm doing something similar and would like to see how it turned out. Thanks!

buening · Sep 25, 2014

See the pics below. Let me know if you have any questions. Shelf length is 48" and as you can see I have a 12" Hitachi miter saw and a Rage 2 chop saw on one of the shelves. Each weighs roughly 45 pounds. The weakness in the cabinet is not the shelf itself but actually the shelf clips. They will bend and pull out of the recessed strips when overloaded, but it takes quite a bit to make this happen. Shelves are 3/4" oak plywood with 1"x1"x1/4" angles screwed to the front. I think I did three wood screws that were recessed in the angles and then had bondo skimmed over the top to eliminate the visual presence of screws. Unless you look at the underside of the shelf or pull back the anti-skid mats, you can't tell there are angles on the shelves.

Lippyp · Sep 26, 2014

I have some deep shelves above my desk in my study. they are ply and rest on 2 x1 battens screwed to the walls on three sides, across the front I have a 2 x 1 batten glued and screwed to the underside of the shelf about 1/4" in. The are loaded up with big reference books and don't sag at all.

buening · Sep 26, 2014

You can do the wood strips at the front, which is very common. I didn't want to constantly catch that board when removing stuff, so I went with the lower profile option of angle iron

sledneck32! · Mar 10, 2016

buening said:
See the pics below. Let me know if you have any questions. Shelf length is 48" and as you can see I have a 12" Hitachi miter saw and a Rage 2 chop saw on one of the shelves. Each weighs roughly 45 pounds. The weakness in the cabinet is not the shelf itself but actually the shelf clips. They will bend and pull out of the recessed strips when overloaded, but it takes quite a bit to make this happen. Shelves are 3/4" oak plywood with 1"x1"x1/4" angles screwed to the front. I think I did three wood screws that were recessed in the angles and then had bondo skimmed over the top to eliminate the visual presence of screws. Unless you look at the underside of the shelf or pull back the anti-skid mats, you can't tell there are angles on the shelves.

Looks like you sprayed everything with a high gloss enamel?

What r your doors made out of? Anymore pics from further back or different angles? Looking at tackling something along these lines pretty quick myself.

Sent from my LG-H811 using Tapatalk

cgrutt · Mar 10, 2016

You can cap off the plywood on all sides with some hard wood. Even if you trim it flush it will be stronger than plywood. I know you said you are hanging shelves on clips but I'd probably put a couple of hardwood blocks in the back of the shelf and screw it to back of cabinet and down through top of shelf once you've got placement set. What about keeping shelving fixed and run it into a long rabbet along back and sides?

buening · Mar 10, 2016

Yep, gloss enamel from Rustoleum was thinned and sprayed from a HVLP gun.

Doors are 3/4" MDF. They make better doors than plywood, as they warp less and are more dimensionally stable.

There are a few more pics here: http://www.garagejournal.com/forum/showthread.php?p=5582276#post5582276

If you have specific things you need me to take pictures of, I can. Just let me know!

cgrutt, I wanted to keep the shelves adjustable since I was building my assortment of tools and shop supplies. The cabinets have made 3 house moves and I think I've settled on a final layout. I've had over 100 pounds on these shelves with no issues. The clips tend to collapse over time, so I'm going to put spacers in the gaps of the clips to prevent this from happening.

Cabinet shelf stiffener ideas?

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