How to support a large desk?

[JWDESIGN]

Hey all,

I'm very new to any DIY kind of thing and hoping someone can help me with some advice on how to support a large desk.

I'm looking to get a particle board/laminate benchtop that is 2460mm(W) x 900mm(D) x 38mm(H) and weighs 51kg.

It will support 3x monitors (~5kg each), 2x monitor arms (~5kg each), 2x Speakers (~2.5kg each) all at the back of the desk and centered to the width of the desk.

I will also want to place my computer on top of the desk with dimensions of 240mm(W) x 515mm(D) and weighing ~20kg to the right of my monitors.

I've messed around with a couple considerations (2nd pic), including some desk drawers underneath each side at the front, with 3x desk legs situated at the back but unsure if this would provide the required support.

Hoping to get some advice on what type of supports/legs to use, best placement for them and anything that can help to prevent any type of sag through the middle of the desk top. If there is a solution that doesn't involve a desk leg situated in the exact centre of the desk, that would also be much appreciated.

[SensibleHill]

Hello, I made a corner desk once with similar considerations. Instead of legs, if you make squares/rectangles out of things like this https://www.bunnings.com.au/70-x-35mm-2-4m-short-pine-kd_p0165357 with this sort of join

Then you end up with pretty sturdy structures. Then, you place these probably two units along the back, two on the sides, two across the front and if you want it really strong, two underneath, e.g. like in the below.

You can bolt them into posts for easy joining. Then, securing the top can be as simple as using a whole bunch of these little brackets https://www.bunnings.com.au/zenith-20mm-zinc-plated-angle-bracket-16-pack_p0044061 

It means you are distributing the load across more surface area of the stronger timbers which then transfers that through the lap joins into the vertical members. I was able to stand on my (admittedly not as wide) desk. Also, instead of attaching your monitor arms to the desk surface, you can secure them to the more robust supporting timbers underneath. If you wanted it prettier (and stronger), you also have the option of attaching plywood panels to the outside of each square unit.

Also, if you assemble all this with screws and bolts, it is straightforward (if tedious) to disassemble it for moving, which is something I did with my desk many times. It's a bit unconventional and needs a bit more work to make pretty but it sure was practical and easy to do.

[JWDESIGN]

Thanks for the help mate,

Would something similar to this be worth it, instead of having those angled cuts and then getting a 4th leg or is that too overkill do you think?

I don't mind the idea of the frame underneath and then plywood over the top to 'smooth' it out. Out of curiosity would there be any metal kind of flatter brackets that could work and provide the same strength or is wood the way to go here?

[SensibleHill]

Ah I should clarify, I meant that the squares are placed vertically as though they are legs. That way, you can leave the area for the human legs clear of supports for the desk legs. However, in a similar fashion, what you've pictured will add strength but figuring out quite how much is sufficient is another question. One thing to bear in mind is that having supports attached to the underside can really suck if you have tall legs or like to cross your legs on your chair etc. I preferred to keep the area in front of the human completely clear.

[JWDESIGN]

Ahh yep that makes sense. Yeah leaving the centre open is a key for me as well, I may be able to get away with a central leg positioned at the back of the desk though with the desk being 900mm deep. My current one is 800mm deep and I only reach the wall if I stretch my legs out all the way.

Might be something I kind of have to reconsider the sizing of the desk itself. It absolutely needs to be 800mm+ deep but I may be able to get away with having a shorter desk top to make it easier to support.

Thanks again for your help.

[SensibleHill]

The key is that whereever you put the legs, if you add horizontal bracing between them that the desktop rests on, you're adding better support and distributing the load better. I quite liked making the frame of vertical squares, particularly having some that are perpendicular to others, as it helped add a horizontal rigidity to the design (i.e. no matter the weight on top it was safe from being pushed from the sides).

[JacobZ]

Hi @JWDESIGN,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

It's fantastic to see @SensibleHill has already jumped in with some great advice.

At 38mm thick, your desktop is already going to be pretty solid, but additional reinforcing will likely be worthwhile. I think using 4 legs at the back with your 2 drawer units at the front would be good. Something like these Taskmaster 700 x 50mm Black Steel Table Legs mounted to the underside of the tabletop would be a good option.

I would install the legs and the drawers, then assess how the desk feels. You can always add some bracing to the underside of the desk after testing if you feel that it is needed. The bracing could be made from timber or steel, depending on what you prefer. 70x35 pine or some Australian Handyman Supplies 50 x 25 x 2.0mm x 2.0m Painted Rectangle Hollow Section Steel would work.

As the main area that needs support is between the drawers, something as simple as this should be enough.

Being 38mm, you would have plenty of room for screws to go up into the underside of the desktop.

Let me know what you think. I am happy to help out further if you have more questions.

Jacob

[JWDESIGN]

Awesome thanks for the help as well Jacob.

Think that is probably the way to go with the 2 drawers at the front and 4 legs at the back first just to see how it fairs as its probably the closest to how aesthetically pleasing it could get with what I kind of want.

Just a quick question with the bracing if I require it. I'm a real beginner with anything DIY related and would that bracing just be joined to itself with right angle brackets and then the desk with some more right angle brackets or is there a better way to do that?

[EricL]

Hello @JWDESIGN 

Timber can be joined onto itself like a surface-to-surface join. The use of angle brackets is highly recommended as this simplifies structural bracing and makes it easy to anchor two pieces of timber together. 

Eric

[JWDESIGN]

Thanks Eric, that's good to know.