Deciding if I need to add a support beam in the middle or if it will be fine on its own.

  • Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
    – Community Bot
    Oct 2 '21 at 12:01
  • How much weight is this thing being loaded with? Oct 2 '21 at 12:42
  • @whatsisname I implied that when I said it would bend if I sat on it. The magic comment deleter passed by.
    – Solar Mike
    Oct 2 '21 at 15:19

According to Ikea, an Alex drawer bank cabinet is slightly over 14 inches wide. So 28 inches of the 96-inch desktop will be supported, leaving a 68-inch span open between the Alexes.

According to a shelf sag calculator website, https://woodbin.com/calcs/sagulator/, entering a 68-inch span of 24-inch-wide and 1-1/2-inch-thick birch, then entering a weight on the middle of the 'shelf' yields:

no weight, no sag

40 pounds in the middle, 1/8" sag

100 pounds in the middle, 1/4" sag

So how much sag depends on what gets put on the desk and where. If you don't plan to load the desk with more than a monitor, keyboard, mouse and elbows, there will be almost no visible sag.

An Alex is 27 1/2 inches tall, so there is room for an edge along the front and back of the desktop to stiffen the desktop if desired and still have 24-25 inches of vertical knee space. A 2 inch by 3/4 inch strip of suitable wood on edge attached as a facia on front and back will considerably stiffen against visible sagging. Even strips of 1 or 1-1/2 inch L-angle aluminum will help against visible sag.

Unless you're planning this desk to hold a lawyer's worth of law books, you should not need a separate center support.


If the desk sags more than you'd like when loaded, you could turn it over every so often (e.g., once or rwice a year). That would also equalize exposure of both sides to light so as to even out fading effects.


Does is already have a natural bow in one direction? If it does, you could put the crown side up and call it a day. Otherwise, I think I would put a small beam on the side opposite the one where you sit or stand.


I would definitely add reinforcement. 8 feet is a long clear span...it's almost guaranteed to sag over time, even with modest loads.

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