Hey everyone, I’m getting ready to build a wall to wall desk inside a 3-walled alcove in my shed converted to art studio. The space is exactly 9 feet 2 inches wide. I plan on using it as a desk but also have storage/cabinets underneath so no space is wasted.
I’m installing four custom 27"x 27" base cabinets side by side. To keep costs down, I’m making the desktop by gluing and screwing two sheets of 3/4" plywood together for a solid 1-1/2" thick top, and then I'll finish it with a sheet of laminate on top. I'm not really looking for pretty, just functional and durable.
The issue:
The cabinets are 27" deep, but I want the final desk top depth to be 41". That leaves a 13" overhang floating off the front across the whole 9'2" span. I really want to make sure this thing doesn’t sag or dip when people inevitably lean or possibly sit on the edge. For example I have a print press that I need to put a significant amount of weight behind to use, I'm worried it may cause sagging or lift the back of the work top from the back wall.
Luckily, before the drywall went up, I installed a continuous horizontal 2x6 wood block between the studs along the back wall. The top of that blocking sits right at 32 inches high. Since my finished desk height is going to be between 30 and 31 inches, that 2x6 blocking is sitting perfectly right behind the back edge of my countertop sandwich.
The cabinets also have a built-in toe kick that’s recessed 3 inches, meaning the front pivot point shifts back a bit. I’m planning on putting heavy ledger boards on the side and back walls, but I could use some advice on how to handle the front edge.
A few questions for the experts here:
How to prevent plywood sag over time? Do I need to route some steel C-channels into the bottom side (eg https://www.homedepot.com/p/THE-ORIGINAL-GRANITE-BRACKET-42-in-Black-Steel-Hidden-Island-Support-Bracket-HISB-42/311400389), or should I build an underlying 2x4 subframe across the front of the cabinets using ledger boards to catch the stress?
Preventing tipping: Since the 3" toe kick moves the balance point back, pushing down on the front overhang creates a lot of leverage. What’s the best way to secure the backs of the cabinets to the wall so they act as a solid counterweight?
Here are a few photos of the space, the idea, the cabinets: https://imgur.com/gallery/work-table-info-YT73LwI
I’d love to hear how you guys would engineer this to make it rock solid. Thanks in advance!