I have a metal frame with bars spaced more than 5" apart (Amazon link). I have a 10" hybrid spring single-sided Queen mattress that uses TPS quadcoils and a 1" 50ILD foam base.
I considered placing a pegboard or Birch plywood layer on top of the metal frame, but I figured it would be simple enough to add whitewood board (from Lowe’s) that is cut so that it’s 81" long and placed length-wise on the Queen frame, supported by the metal bars. These slats would be spaced 1" apart and held together by cotton webbing stapled on them.
I have never seen slats that are used length-wise, are there any concerns in how it affects the mattress that I need to consider here? I’m not concerned as much about sturdiness since it would be on top of the metal slats.
Ultimately, it would be 1"x3"x81" length-wise slats spaced 1" apart with about 15-17 of those boards to fill the 60" width. Is the 1" slat spacing okay? Would this pose any issues with ventilation?
There are plenty of frames that use vertical slats. As long as there are enough horizontal slats to support them.
The 1" slat spacing between the 3" slats should generally provide adequate ventilation for your mattress. Ventilation is important to prevent moisture buildup and help keep the mattress fresh. A 1" gap is typically sufficient to allow air circulation, although wider spacing would offer more airflow. That is true, but consider what it would be like if you used a solid platform or pegboard.
The length-wise placement of slats is not an issue as long as the slats are properly supported and spaced evenly.
Your setup should work well as long as the slats are spaced correctly and evenly, and the mattress is properly supported.
As a follow up question, what would be a good maximum slat spacing if I want to be able to support every kind of mattress in the future, including softer latex or memory foam?
I’m understanding 2.5”-3” is industry standard, I imagine this will work for coil and hybrid mattresses, however I’ve read that softer mattress like latex and memory foam can sink into the slat spacings over time. Is this a concern? Can this be solved with less slat spacing, or does this require a flat board? For the former, what would be a good maximum custom spacing to support every kind of mattress?
I ask because I’m considering saving some cost on wood by using a larger spacing.
Less than 3" 2-2.75 is optimal in my opinion. Anything more than 0.5" but less than 3". You don’t find many under 2" as standard stock. Tempur-pedic actually recommends a platform.