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I'm planning to make this desk for a person who has asked to leave off the front of the apron. She's very short and has difficulty with most desks being too high, and the ones that aren't too high don't have enough clearance underneath.

Will a 3/4" piece of plywood hold across a span of slightly under 3 feet?

And would the answer to this be different if I edged the plywood with 1 inch of hardwood (walnut)?

Desk

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  • "And would the answer to this be different if I edge-banded the plywood with 1 inch of hardwood (walnut)?" Yes, very much so. And additionally so depending on how you actually implement your hardwood edging. See previous Answers 1 and 2.
    – Graphus
    Jan 17, 2021 at 15:13
  • You might find that a laminated hardwood top would be vastly stiffer than ply. (There is a huge range available online, from the cheap-but-disappointing ikea top I just bought to what are probably very nice and expensive custom tops.) That size should be quite easy to source and price competitive with ply.
    – Aloysius Defenestrate
    Jan 17, 2021 at 22:45
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    Skipping the apron but adding support for the top halfway or even 2/3 the way back would help a bit and likely not be obtrusive.
    – Hart CO
    Jan 25, 2021 at 0:15

3 Answers 3

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3/4 plywood over a 3' span is likely to be fine as long as she does not sit or climb up on it, or leave heavy objects near the edge for long periods of time.

I am sitting at a desk, as i right this that is 3/4 plywood spanning 6' and it is fine. If i put a straight edge on it i think i may see a sag of about an 1/8", with out my heavy arms resting on it to use the keyboard, but it will flex significantly if press down on it.

I think it will be fine but since you have not built it yet you may want to go with either a thicker ply, thicker solid wood or butcher block. A Aesthetically i think it will look better on the thick base.

And would the answer to this be different if I edge-banded the plywood with 1 inch of hardwood (walnut)?

The thicker walnut hardwood would add stiffness but not take all of the flex out of it.

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  • Thanks. I'm going to look for 1 inch thick walnut veneer plywood.
    – John
    Jan 16, 2021 at 20:50
  • It may? be cheaper to go with 1 1/8" floor decking and veneer it yourself. - lowes.com/pd/… -
    – Alaska Man
    Jan 17, 2021 at 9:18
  • @John, if you want to make the top thicker for peace of mind possibly a much cheaper option than 1" walnut-veneer hardwood plywood would be to use the ply you were originally intending to use and simply screw/nail and glue a second layer of lesser ply to the underside. This second piece can be 1/2" but go with 3/4" if you want to go even further on the reinforcement. FWIW I think a thicker top (or just an apparently thicker top) would certainly look better on a rustic/farmhouse style table design such as this.
    – Graphus
    Jan 17, 2021 at 15:00
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    Re. your suggestions in the third para, can we please not be another source that perpetuates the incorrect use of the term butcher block?
    – Graphus
    Jan 17, 2021 at 15:26
  • It might not sag enough that you're worried about it breaking, but a flimsier top can cause some vibration issues. I've used a desk where the monitors would wobble as someone walked by, and even typing at a consistent speed would make the monitor start to bounce a bit. People are bothered by such things to varying degrees, so might not matter on this relatively small desk.
    – Hart CO
    Jan 25, 2021 at 0:22
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Use the Sagulator to find out. I entered your dimensions, assumed a load of 30 lbs distributed over the top, and said you're using 3/4" fir plywood. The total calculated sag was 0.01", which seems quite acceptable.

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  • What if a 120# child jumps, or a 260# man sits on the front of the desk?
    – gnicko
    Jan 18, 2021 at 19:19
  • @GregNickoloff Then it'll temporarily sag 0.03". But a 260 lb person ought not to go around sitting on other people's furniture.
    – Caleb
    Jan 18, 2021 at 21:21
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    No doubt. But people do stupid things all the time.
    – gnicko
    Jan 19, 2021 at 16:34
  • Wow how did you know exactly how much I weigh.
    – John
    Jan 25, 2021 at 18:37
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John, I designed a desk using 3/4 birch plywood for the top and put a piece of poplar shelf edging on the horizontal edge and this helps a lot to prevent sagging. Also, I made a farmhouse TV stand which is very similar to the style of your desk. I used 2x2 inch poplar for the legs and 1x1 inch poplar for the diagonal braces. I also agree with the others who said that a thicker top would look much better for this type of desk and also eliminate any sagging issues. 2 options.

    1. I used a biscuit joiner and then glued and clamped 2x8s together. It turned out fantastic and a 300lb man could stand on it.
    1. For another piece, I used plywood top but wanted a beefier look so I glued 1x2 poplar laid flat all around the perimeter. When the top was sanded and stained with a dark stain it looks like solid stock.
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