Long shelves and sagging

[Chris Vander]

Hi. I've been tasked with building floor to ceiling shelves in our laundry room by the wife. Vertical height of 10', span of 79", depth 22". I want to avoid using metal hardware to support the shelves. After extensive reading and consultation with the almighty sagulator, I ended up building the casing and shelves out of face glued 3/4" maple plywood to make 1 1/2" thick stock. I routed 1/2" deep dadoes into the sides and everything fits together nicely. As of now, no sagging is seen and I am planning on adding a 1" x 1 1/2" face frame to the entire unit.

Maybe I'm just looking for reassurance (or some hard truth), but do you all think this will hold up? I know it's dependent on load, I estimated 30lb/ft on the sagulator (which I think will be high). I can still retrofit with a stud-mounted rail in the back or brackets (heaven forbid) if necessary. Thanks for your input, pics are below.

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[Tom M King]

Google "sagulator"

[Chris Vander]

I did. I used it, as I stated in the post. Am I missing something?

[Tom M King]

Sorry, typed too fast. went back to delete my post but it wouldn't let me for some reason.

[John Schweikert]

Personally I think a center piece all the way up would look better and provide support. There is something less natural about very long shelves. Unless you have 6 foot long items that need to be laid flat, there's no practicality to a shelf that long.

At this point just install vertical ply up the center, add your face frame so you have two sets of shelving side by side and be done with it. It will look great and no issues of sagging. I can't say I have ever seen over 6 foot long shelves in any books on built-ins nor when visiting homes. Just in my neighborhood, I've seen close to 100 homes over the decade from our annual home tour, both 100 year old houses and brand new. Shorter shelves look good.

[Chris Vander]

No worries Tom. I was just confused.

[Tom M King]

I was talking to someone about something else while I was reading. Just trying to do too many things at the same time.

I found this with Google: http://www.woodworkingtips.com/etips/etip01.html

[Sam Murdoch]

79" is a long span but the 2 layers of face glued ply will be very rugged. With the added face frame glued to the shelves you will be fine. If you want to make extra certain add a 1-1/2" to 2 " cleats along the back under each shelf. I would have glued and screwed a 1/2" plywood back. If that is still an option do that rather than the back cleats.

John's idea about a center vert is good advice and practical too. Solves all your concerns. Means another vertical for the face frame but that's easy enough.

[John Sanford]

What John said...

[David Weaver]

I would also run a center piece up the middle, one that's not full depth - maybe 2/3rds. I've lamented doing that on an all wood (no plywood shelf) bookshelf, but once there's stuff on the shelves, it doesn't detract from anything at all and right before you install the center support will be the last time you burden yourself thinking about whether or not the shelf will sag.

[Lee Schierer]

Locate two of the studs near the center of your shelf and add pocket holes to the underside of the shelves at those locations. Put screws through the pocket holes into the studs such that at least 1" of screw is into the stud and you should have no problems with sagging and the screws will hold you unit to the wall.

[Brian Tymchak]

Maybe just a stile on the front in the middle (instead of a full vertical panel) with shelf supports will alleviate any sagging. I think that's what I'm going to do when I get around to building some cabinets for my garage that will have long shelves.

[Pat Barry]

For a span like that, even with the doubled up plywood which is very strong, I think you still should have the center stile on the face frame and on the back with cleats or a stile or supports similar to what Sam described. You don't need the full width of the shelf supports as the sag will be negligible in the in-and-out direction but definitely the front and back edges. That way you can keep the shelf unit virtually wide open and not be so restricted by a full center divider on each shelf

[Mark Wooden]

Unless you're storing books, heavy boxes/ bottles, canned goods etc, a simple cleat at the back of each shelf screwed to the studs in the wall should do it. If you're doing a 1" thick face frame, that's going too stiffen it too. If you're going to really load them up, then run a vertical stile in the middle with a block screwed to the back of it under each shelf. No front to back blocking should be needed, keep the free space length.

[Larry Edgerton]

I did one similar for a librarian and she did not want any center support showing. It was going to be loaded with books. My solution was to run a diagonal support, not quite out to the front and cut the inside out of old books the that were large enough to cover it. She was happy, and so was I.

Larry

[Chris Vander]

Thanks all for your input, a lot of great ideas. For now, I think I will add the cleat behind in addition to the face frame and see how it holds. If it becomes an issue, will probably add a center stile. Thanks!

[David Gutierrez]

you have the full scale model done why not just put some weight on it and see how it reacts?

[Brian W Smith]

Just posting this as a "last resort"...and not really recommending,just sayin.....

Think truss rod.Guitars use them....old school,wooden step ladders do as well....Basically it's a metal,"truss rod" that gets "buried" into whatever you're trying to support.It get's threaded ends...to which we use nuts to tension the bowed "section".How this interfaces with high end WW'ing definitely ain't for the faint of heart,IE;these are most always custom fabricated/machined parts($$$).......but,you can pretty much write your own specs with regard to loading.

[Kenneth Walton]

I just did my pantry with 54" shelves similar to what you did, but single layer shelves. I added a 1.5" face frame, and that was pretty darn sturdy. I ended up adding a small center cleat screwed to the back wall, and that really shored things up nicely.