Shelf span ?'s

[Mike Hoyt]

Hey guys, Im just thinking about putting together some quick bookshelves. Im thinking about 4' long by 3' tall and about 10 inches deep. I was wondering if I am looking for trouble trying to have a 4 foot long shelf. I am going to use 3/4" ply with some sort of face frame. Do you guys think I need more support or will I be OK.

Thanks, Mike

[terry hansen]

if you google shelf sag calculator - you'll get woodbins sagulator, where you can determine sag based on a variety of factors.

I have never tried a 4 ft span unsupported. As my SO would load the shelf to full, no matter the weight, I would use a front edge support (L shaped hardwood) at the minimum and likely add one a straight one at back edge too.

[Prashun Patel]

By faceframe do you mean hardwood edge band? That'll stiffen the shelf a little. A rear cleat will also help significantly.

[Glenn Clabo]

Check this out
http://www.taunton.com/finewoodworking/SkillsAndTechniques/SkillsAndTechniquesArticle.aspx?id=28101
and this
http://www.woodbin.com/calcs/sagulator.htm