8' Bookshelf span.

[trad4life]

Good morning,

I'm hoping to build a bookshelf unit that wraps around a 6' H by 8' L window that is centered on a 10' X10' wall. Leaving a 3" reveal off the trim, what I envision is two thin bookshelves that come up each side of the window merging into the longer bookshelf that will run the full width of the wall. I'd like to solicit some advice on how to support the bookshelf over the 8' length of the window. Would it make sense to use discreet brackets attached to studs in the 3" reveal space above the window trim, within the book shelf space itself, or think about trying to hang it from 2nd floor joists. Any experience or advice would be greatly appreciated.

Thanks,

Craig

[rmac]

Two questions:

1. Are you planning to put a back on the shelving units, or are they going to be open (so you can see the wall behind the books)?

2. Do you want the 8' part jammed up against the ceiling, or are you planning a gap there to accommodate an uneven ceiling, and/or moulding in the corner where the wall meets the ceiling, etc?

-- Russ

[flairwoodworks]

Good morning,

I'm hoping to build a bookshelf unit that wraps around a 6' H by 8' L window that is centered on a 10' X10' wall. Leaving a 3" reveal off the trim, what I envision is two thin bookshelves that come up each side of the window merging into the longer bookshelf that will run the full width of the wall. I'd like to solicit some advice on how to support the bookshelf over the 8' length of the window. Would it make sense to use discreet brackets attached to studs in the 3" reveal space above the window trim, within the book shelf space itself, or think about trying to hang it from 2nd floor joists. Any experience or advice would be greatly appreciated.

Thanks,

Craig

Craig,

To prevent the shelf from sagging, you could inset some aluminum (or steel) angle.

[jHop]

I don't remember where I saw it, but there is a chart somewhere on the web that states how much sag shelves will have based off their material. The only solid fact I remember is that shelves will sag with anything over 12" of length with about 3/4" thick shelves. Adding a 3/4" thick piece to the front of the shelf will increase the distance before sag appears, and a 1" piece adds even more. You should have enough stability to go 16" in distance, which will match the studs (hopefully). If you are building a back to the shelves, I'd put divider in between the shelves at 18 to 24". If they are to be built in, I'd just go 18". I'll see if I can find that chart on sag, though.

[jHop]

I'm glad I went looking...

http://www.woodbin.com/ref/furniture/shelves.htm

I took a glance at the info, and the numbers I quoted were off.

[Beechwood Chip]

There's also the sagulator. My father taught me that any horizontal beam supported at the ends will sag - the question is how much.

Another option is to make the shelf a torsion box.

[JayWC]

There's also the sagulator. My father taught me that any horizontal beam supported at the ends will sag - the question is how much.

Another option is to make the shelf a torsion box.

Even the torsion box will sag after a while. It's a matter of how much can you live with.

[iSawitFirst]

I think I'd go with thin metal brackets every 16". They disappear once the shelves are full of books.

I'd also consider putting a 1.5" tall wood face on the shelf and increasing the bracket spacing to 32".

What are you doing to prevent racking?

[Vermont Carpentry]

Good call Beechwood. The sagulator is the one I use. I also install hardwood trim to the front and rear of the shelves and attach them by cutting a T&G or dados and a spline to increase rigidity.

Mark

[ChetlovesMer]

I'm a big fan of the torsion box with steel tubes hidden inside. I wish I had a picture, but I did something like that in my old house as a window seat. We lived there 11 years and it was still true the day we moved out. The steel tubes run perpendicular to the wall on which you are going to mount the box. Then put holes in the torsions, or what ever they are called over which to slide the tubes. I'm telling you rock steady, lasts forever, looks like a magic trick.

[trad4life]

Thanks for the input everybody. Its very helpful seeing how other people approach this situation/predicament. Now I all I need to do is decide how to move forward! Thanks again.

-Craig

[Vermont Carpentry]

Chet,

Do the steel tubes have a flange that allow you to bolt/lag into the wall structure? Sounds interesting and since I do more remodeling than woodworking I might come across this very situation,

Thanks,

Mark

[ChetlovesMer]

Chet,

Do the steel tubes have a flange that allow you to bolt/lag into the wall structure? Sounds interesting and since I do more remodeling than woodworking I might come across this very situation,

Thanks,

Mark

There are three ways to do it. I personally like to drill holes at 2 degrees above parallel to the floor into the wall-studs. (3 inches deep, 3-1/2 to account for the drywall) Then Jam the steel tubes into the studs. (BTW, by steel tubes normally I mean black pipe. Works great/dirt cheap.) When the tubes are inserted they will end up level even though the holes are 2 degrees above parallel.

I've seen others weld a flange on the back of the tubes creating something that looks like a huge comb with very few teeth (if that visual makes sence?)

The last option is a series of L brackets mounted horizontally. This method works but I don't think it is as solid as either or the other two. If you go with drilling the holes, be darn sure you know where you want the shelf because it becomes quite a challenge to move it later. You also need to be sure to bullseye the stud. There are a bunch of ways to make sure you do that.

One thing I can promise you, between the torsion box and the steel tubes your shelf will still be there in the morning.

[Vermont Carpentry]

Chet,

Thanks for the info.

Mark