What exactly makes a surface/foundation appropriate for this mattress (or any foam mattress)?
We bought a “platform” bed from Costco which is quite nice aside from I don’t think it provides proper support. It has the traditional three slats with two support legs on each slat and five “planks” that extend the entire surface creating what looks like a complete platform surface. The 16 or so inches at the foot of the bed is a solid frame that has drawers underneath. The issue is that the planks are like quarter inch particle boards and are flexible. They’re less flexible when screwed to the slats and end of frame. However, I can press down on the planks and there is noticible flexing, particularly between the slats.
When I first assembled the bed and was immediately concerned by the planks, I created three additional slats from pine boards to narrow the gaps between slats. Due to some variances in measurements (the stock slats are a bit less tall then boards I can buy), this created issues with the two sets of slats having different heights. As a result, the plank surface was actually less stable than with just the three. The mattress felt different in different places, as the platform surface appeared to flex more in different places (when pressed down on without the mattress). In some places (like my side of the bed), the mattess felt quite firm and getting firmer as the night went on to the point of feeling almost bottomed out and hard. This was particularly the case around my lower back which felt lower than my feet or head by morning My wife’s side felt quite a bit softer and she didn’t have issues to this extent. .
I’ve since ditched the extra slats going back to the stock three slat setup with the planks. The mattress on this setup does feel better and more stable. It’s not quite as firm and hasn’t seemed to have sagged/bottomed out as the night goes on. It still doesn’t feel as nice as on the floor and I worry that with time it’ll get worse. We put the mattress directly in the floor last weekend. It felt quite nice and soft on the floor.
So, what makes a good surface for the mattress and how might I best test the surface to determine if it is appropriate? I’ve debated ditching this mattress (we’ve had it maybe 70 days) and just cutting my losses and going with a traditional box spring and inner coil setup. However, I don’t think want to give up quite yet.
I’ve thought about ditching the stock slats and creating 10 or so pine slats (~3" apart). However, the two rail supports that the slats screw into ends maybe 8" before the headboard meaning that the 8"'or so of the mattress at our heads would be unsupported. Unless we used the planks, I suppose. But there would be some flexing in that spot. I also thought about trying to find a bunkie board locally but am not confident in that. I’d want to be able to return it if it doesn’t work out., so I wouldn’t want to buy online. The last thought was buying a box spring (well, foundation…can you even buy box springs with springs in them anymore?). Will furniture stores just sell a box spring? Would it work well with this mattress?
What about this foundation? Would it provide a good surface? If so, would it best go on the three slats or the planks (with slats supporting underneath, obviously)?
https://www.amazon.com/dp/B00OEXUB5I/ref=asc_df_B00OEXUB5I4889373/?tag=hyprod-20&creative=394997&creativeASIN=B00OEXUB5I&linkCode=df0&hvadid=168221741416&hvpos=1o2&hvnetw=g&hvrand=1640949490629864674&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9018952&hvtargid=pla-273778474460#productDescription_secondary_view_div_1489804077234
If it matters, I’m 6’0" and about 150ish pounds. Wife is 5’7" and a bit more in weight (currently pregnant).
Sorry for the super long post. I hope it makes sense. I could get pictures if they’d help. Thanks!