Benchwork-Submitted for your appraisal

SAL Comet

Member
Here's a cross section drawing of my final design. It's cantilevered from the sloped ceiling of my attic/bedroom. The green 2x4 block lays flat against the ceiling and is the point of attachment. Attached to the 2x4 is a long 1x2 1/4" and short vertical 1x2 that ties them together. An L girder of 1x2s runs lengthwise across the front. Decked with 1/2" plywood, everything is glued and screwed. I'm building in sections so if I ever get a better location the benchwork can be removed and the mounting brackets sawed off. It's a pretty narrow shelf (12")but narrow benchwork is far better than no benchwork at all. Any thoughts are welcome.
 

Attachments

  • Benchwork.jpg
    Benchwork.jpg
    31.7 KB · Views: 273
By your use of the term cantilever, I assume there will be no other support except at the ceiling? If there is support at walls at the ends and the span isn't too great, there may be no problem other than sagging at the center.

I'm a bit concerned about your attachment at the ceiling. You're correct in the approach of using a triangle to provide efficient support, but I think the area of support is insufficient. You appear to be projecting about 18" and relying perhaps on support at the about the first 4" or so. I'm not sure that is enough.

Even if all your little parts were fastened rigidly enough by glue & screw, the screws or bolts holding the 2X4 to the rafter need to be sufficient to avoid a long hinge line along the 2x4. I would use a double row of lag bolts to prevent the 2x4 ledger from rolling.

I'm assuming that cutting the sheetrock away is not an option. If it were, I would suggest using 1x3's as your horizontal piece, butted directly to the side of the rafter up to the underside of the roof deck, fasten a piece of scrap to the rafter above the 1x3 and gluing and screwing a triangular plywood gusset to each side of the rafter and 1x3. This would give more substantial area of support.

Why not omit the "L-Girder" to keep weight down and just use a strip of some thin facia material instead? The Girder offers nothing in the way of support. In fact, I'd further reduce the weight byomitting the plywood and use a single layer of 1" foam over such a small area, but that's just my preference.

If you forge ahead with this design, I'd try a short 4' section and give it a few firm tugs to test it out before building the whole layout. Report back and tell me I'm wrong. (Wouldn't be the first time. :) )

Wayne
 

Bikerdad

Member
If you can use a half-lap or saddle joint to connect the vertical 1x2 to the green foundation 2x4, that would be a good thing, as it would vastly increase the surface area for gluing.
 

SAL Comet

Member
Thanks for the input guys, I've installed two 8' sections with 3" drywall screws, one in each 2x4 block. There's a mounting block every 2' at each rafter. So there's 9 screws attaching them. To test the strength of them, I stacked 19 years worth of National Geographic magazines on one section with no noticeable sag. I'm not sure how much the mags. weigh, but they would be about 7' tall in one stack, so I think the benchwork will support a model train just fine. Now I got to get those magazine off there before my girl desides that it would make a good book shelf. :eek:
 
Top