Do I need the apron on this bookcase?

[Mark Gibney]

Here's a Sketchup drawing of a bookcase that is 50" long, and 27" tall. The shelves are 13 1/4" deep, the vertical pieces are 12 1/4" deep. The material is 1" thick white oak.

401977

The clients showed me a photo of a similar looking bookcase. The photo does not show aprons (is that the correct term here?). I told them they are probably there but hidden from view by the angle the shot was taken from. They would prefer I don't use aprons.

I can't see how I can make this bookcase resist racking without aprons.
Would a brace of aircraft cable be sufficient?
They don't have young children who might climb all over this. But still.

Also - how would you go about joining the shelves and upright sections.
That might be the bigger question.

Thanks. Hope to hear what some of you think.

[Rick Potter]

Probably built with half laps. Dado's would be very weak.

The only way to keep it from racking is to specify it is to be screwed to the wall, or build it with a back that could be painted wall color.

My $.02.

[Bill Orbine]

Is this going to be attached to the wall or is it to sit on top of something? You can do without the aprons based on the joinery you use for assembly..... such as sliding dovetails or blind 1/2 dadoes. Or even just dowels/dominoes.

[Bradley Gray]

I would use a back that is rabbeted into the center section.

Housed bridle joint for the shelves/verticals.

[Mark Gibney]

The clients do not want to screw this bookcase to the wall.

Rick - what do you mean by half-lap? Do you mean the shelf and the vertical both have material removed half way across their widths so they can slide onto each other?

Bill - I am considering dominoes but I haven't convinced myself yet.

Bradley - can you grab a napkin and sketch what you mean by a housed bridle joint in this case? I can't picture how that would work when the end of a vertical member is meeting the face of a shelf.

Thank you all for the suggestions.

[Bradley Gray]

here you go:

402000

[Mark Gibney]

Thanks, that what I pictured when Rick suggested half-lap joints.

[mark mcfarlane]

If you did Bradley's joint with 1.5 or 2" white oak, and the joints were very tight, the structure would have decent shear strength. 1" might be OK if the structure isn't carrying much weight and won't be bumped into on the end.

I am a frequent Domino user and I don't see them supporting the shelf extensions, unless these are very short pieces that won't have any weight put on them. They seem to be extending about 8 inches in your diagram, large enough for your client to put 20lb dumbbells on them.

[Rick Potter]

Yup. What Bradley is calling Housed Bridle joints is what I meant by Half Lap. I am sure I have the wrong terminology, I am really bad at that.

His method of using a back is also what I was trying to say.

PS: Nice napkin sketch Bradley

[Jim Becker]

The clients do not want to screw this bookcase to the wall..

Honestly, no matter what joinery you use, this piece will be in danger of racking without something to keep that from happening. For a free-standing bookcase, that would "normally" (term used very loosely) be taken care of with a back panel, but the open nature of this design doesn't provide for that. In the original illustration you provided, there are two horizontal panels that absolutely would provide that support. They could be made smaller or be made from metal angle that has minimal reveal...I'd probably choose the latter because it would be easy to bury the horizontal portion of the metal angle into the face or center of the shelf so there would be minimal exposure. A hidden brace that ties the metal angle into the vertical wood members would keep things pretty stable. The thicker the wood, the easier it will be to hide the support. Using wire certainly has merit but a corner to corner "X" wire setup is going to be visible and your client will have to be ok with that "industrial" look. Someone mentioned fastening to the wall...that's actually a good idea for any bookcase to prevent tipping and could alleviate the racking concern, too, but if the client isn't willing...

[Derek Cohen]

Here's a Sketchup drawing of a bookcase that is 50" long, and 27" tall. The shelves are 13 1/4" deep, the vertical pieces are 12 1/4" deep. The material is 1" thick white oak.

401977

The clients showed me a photo of a similar looking bookcase. The photo does not show aprons (is that the correct term here?). I told them they are probably there but hidden from view by the angle the shot was taken from. They would prefer I don't use aprons.

I can't see how I can make this bookcase resist racking without aprons.
Would a brace of aircraft cable be sufficient?
They don't have young children who might climb all over this. But still.

Also - how would you go about joining the shelves and upright sections.
That might be the bigger question.

Thanks. Hope to hear what some of you think.

Hi Mark

Instead of aprons, add a back to the centre section. That will brace it very securely. A full back (just in this area) will look less intrusive (and less busy) than two separate aprons (which appear to jut out without connection to the design).

Regards from Perth

Derek

[Gary Ragatz]

Honestly, no matter what joinery you use, this piece will be in danger of racking without something to keep that from happening. For a free-standing bookcase, that would "normally" (term used very loosely) be taken care of with a back panel, but the open nature of this design doesn't provide for that. In the original illustration you provided, there are two horizontal panels that absolutely would provide that support. They could be made smaller or be made from metal angle that has minimal reveal...I'd probably choose the latter because it would be easy to bury the horizontal portion of the metal angle into the face or center of the shelf so there would be minimal exposure. A hidden brace that ties the metal angle into the vertical wood members would keep things pretty stable. The thicker the wood, the easier it will be to hide the support. Using wire certainly has merit but a corner to corner "X" wire setup is going to be visible and your client will have to be ok with that "industrial" look. Someone mentioned fastening to the wall...that's actually a good idea for any bookcase to prevent tipping and could alleviate the racking concern, too, but if the client isn't willing...

Running with Jim's idea about metal angle, you might be able to use something like this to add racking support to the four bridle joints.

https://www.homedepot.com/p/Everbilt-3-in-x-3-in-Zinc-Plated-T-Plate-2-Pack-15169/202033997

You could bury the metal plate in shallow dadoes in the back of the shelves & supports so that the bookcase would sit flush to the wall and the T-plate would be hidden. Not as effective as a back panel, but ...

[glenn bradley]

Jim Becker hit my main concern. I think you are getting the drift by the responses here. Some ideas don't translate well into the real world. There are proven structural methods that work and ones that fail. That structure, free standing, is likely to fail. Something has to provide adequate strength to resist the use model. Corner joints only, although they may stand for a while if you're careful, cannot overrule the leverage that a load and a lateral bump would deliver.

[Rod Sheridan]

Hi, a narrow French cleat the length of the top, attached to the wall would prevent racking and tipping, and would be unobtrusive.

A rebate type as opposed to a bevel type is what I would I use, it could register in a groove on the underside of the top...........Rod.

[Bill Dufour]

Where do they plan to place this unattached bookcase? It can hold enough weight to kill them when it falls on their head from a height. probably above the bed? It has been 24 years since the last big quake in LA so they are due for another one. Do they have animals?
Bill D.

[Pat Barry]

With that thickness oak over the apparent spans, there would be no need for worry about sag, so the apron isn't necessary. What seems to he needed is someway to inhibit racking. If you build it with the housed half lap as suggested it may be enough. You could test it after assembky. If needed, you could add a couple T shaped metal braces on the back side. Inset into matching mortices and solve your racking concerns and keep the appearance as drawn.

[Mark Gibney]

Well thank you all, you have confirmed my thought that this bookcase really does need either a back, however minimal, or to be attached to the wall in some fashion.

Derek - good observation that the two aprons are ugly. My special superpower with Sketchup is to make anything I draw look ugly.
I think I'll try to sell the clients on the idea of a back on just the central back area.
It's a fairly low bookcase, sitting on the floor in a narrow room, and I don't think these aprons or a back will be visible to anyone who doesn't get down on their knees to check it out.

Thanks guys.

[Rick Potter]

No attachment to wall? No back? No skirts?

No deal.

They would come back complaining about it not being sturdy.

[Tom Bender]

Derek has the best idea though support for the ailerons will still be a concern. You could get considerable strength by adding 1 x 1 corner blocks under each shelf (8 total or 4 if you install the Derek fix) and they will not be very noticeable if they are a few inches short of the front. That is a very deep bookcase.