Butcherblock Floating Desk

[HerneHillBilly]

I'm new to DIY and am building a floating desk made from 40mm thick beech butcher block the type used for kitchen worktops. The desk must be supported entirely from walls made of plaster over lath on 2x4 studs (late 1800's Victorian house).

The dimensions of the worktop are 2460x720x40 and 2300x720x40 in an L shape and the weight will be roughly 40-50kg for each side of the L. It will hold some computer monitors and keyboards but the main weight will be the desk itself.

I've purchased 580mm length Hafele shelf supports similar to these:
http://www.hafele.co.uk/Hafele35a1/...g_id=11588&title=Hebgo+fixed+brackets,+150+kg
A support will be mounted roughly every 30" along the wall.

My question is what is the best way to fix these supports to the wall?

My idea is to mount each support on 200x18mm thick plywood sandwiched between 2mm sheet metal with machine bolts going through the metal and plywood. The plywood and metal sandwich will be fixed to the studs in three or four places vertically with long lag screws.

I will also mount a 2x4 along the length of the desk between each support for added strength.

Does this sound like a reasonable design or will the desk cave in under its own weight possibly taking the wall with it?

I'm a DIY novice.

 

[RonnyRaygun]

Make sure you join the two pieces of worktop together using steel plates. That way it becomes far stonger as they will be unable to move independently.

Make sure that you fix your brackets into the studs and not just into the wall, so the positioning of your brackets will be governed by the position of the studs.
I'd also remove the lath and plaster locally so that the brackets are tight to the studs otherwise you risk crushing the lath and plaster. You can always fill back over them afterwards.

It looks like only a short distance between the top and bottom fixings so you will have some large forces in the screws, so use the longest, thickest screws that are practical.

 

[big-all]

to much weight to big a span
can you not live with a couple off chrome legs at the front

 

[HerneHillBilly]

Thanks Ronnie.

Make sure you join the two pieces of worktop together using steel plates. That way it becomes far stonger as they will be unable to move independently.

Good point haven't thought of using steel plates. The butcherblock will have built-in butt joints like for kitchen worktops. I'll also have a 2x4 extending beyond the wall to partially support the overhang beyond the last support.

I'd also remove the lath and plaster locally so that the brackets are tight to the studs otherwise you risk crushing the lath and plaster. You can always fill back over them afterwards.

Another good point. Thanks.

use the longest, thickest screws that are practical.

Yep, point taken. thanks.

 

[HerneHillBilly]

to much weight to big a span
can you not live with a couple off chrome legs at the front

I could do that but then the floating desk wouldn't be floating, right?

The point being that its an L shape and the legs get in the way of putting a couple of pedestal drawers I've got underneath the desk.

 

[catlad]

If you position the drawers right they might catch your desk when it gets tired of floating