DIY Foundation vs Bunkie Board?

Any feedback concerning making a DIY foundation out of plywood versus buying a bunkie board online?

I finally bought a mattress! Yay! An 11" innerspring mattress from a Trusted Member.

I have a metal platform bed. It’s 18" high with slats spaced 6.5" apart.

The salesperson said he did not recommend a boxspring or bunkie board because my mattress would be too high. He recommended using cardboard or plywood instead (which he said would not affect the mattress warranty).

I see “bunkie boards” online that are about an inch high, which would be basically the same height as a DIY plywood foundation (either way my mattress would be about 30" high). But just because they are described as “bunkie boards” doesn’t mean they will be a good foundation. EX - one I see has wood slats that are 12.5" apart, another metal one looks exactly like my bed frame, but the slats are 5" apart. How do I find a good bunkie board?

Any feedback about making a DIY plywood foundation?

  • Plywood should be at least 3/4" thick
  • Birch plywood? Moisture resistant plywood? (just be careful that it has rounded edges and isn’t going to snag the mattress)
  • Holes are needed for ventilation: 3/8" diameter, spaced about 4-6 inches apart along the space between bedframe slats (will probably be between 50-100 holes)
  • Buy two 4x8 sheets, cut to 4x5 (one on top half of bed and one on bottom half). Bed is 59" x 79"

I read pegboard is also an option, although it appears that pegboard would cost significantly more than plywood?

This is what my bedframe looks like:

Hi (again) Cassandra!

Oh it’s so great to hear you found a mattress! I definitely would heed the experts advice, as they know their product best. I think - and you may want to reach out to them to clarify - that the bunkie boards don’t always allow for the right “breathing” for the mattress.

Are you looking to overlay this atop your current frame, or are you constructing something entirely new? You can find all pre-existing convos about DIY wood foundations here. That’s where I’d recommend starting! I also hope experienced DIYers chime in with their thoughts.


Yes! I’m so excited to have finally bought a mattress, although I’m nervous waiting for it to arrive so I can see how I feel after a night’s sleep (so much anxiety that I’ll wake up in unbearable pain every day :sob:)

The only reason the salesperson said he didn’t recommend a boxspring or bunkie board was because of the height. I did think it strange that they weren’t concerned with the mattress’s foundation (and I recall the salesperson making the same comments when I visited at the beginning of the summer).

Thank you for the mattress foundation search link. I had search myself, but kind of wishing I could find a thorough tutorial somewhere that walked me through everything. I’m mostly finding how to DIY an entire bedframe, but I have a metal platform bed frame (slats are 6" apart) and I just need something to put on top of that.

I do have my current mattress directly on the frame. I don’t notice any sagging issues (if I look underneath, the mattress sticks out maybe 1/4-1/2" between the slats?), but I want to ensure I “do everything right” with this new mattress.