You can always add center support legs from amazon to the KD. Kind of surprised they are flexing as mine have not, but my bed frame has cross slats and center supports
They’re not even laying right I had to use velcro, I sent them a video and they didn’t even respond so whatever with them.. this is what I have Heavy Duty Queen Bed Frame on Glides (Bedrock™) | Knickerbocker Store
Being that there is a middle support on the frame head to toe, the engage goes across will that even work? Knickerbocker enGauge™ Frame - Jordan’s Furniture
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Yes you can use those center supports 3 across the top 3rd and 3 across the bottom 3rd almost as if knickerbocker used 3 rails across, just you created your own. I hate when companies dont respond!
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I know it speaks volumes for sure! so the wood KD frame on top of the engauge or one of those even though their bar does not go down the center top to bottom?
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Yes with something like this to create a simulated 2nd and 3rd cross bar.
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The embrace frame has more support but the price is ridiculous…
Full disclosure: Hendrik with CBH Wood Furniture / Swiss Dream Beds (Trusted Member) — we build solid-wood, metal-free bed systems with natural latex.
On the original question: I would be cautious putting a latex DIY stack on a steel wire / semi-flex style foundation. Latex wants a fairly even support surface. Gaps or narrow wires can create pressure lines in the bottom layer over time, even if fabric covers them. Breathability is a real plus versus a solid Tempur-style board in a humid room, but breathability doesn’t help if the latex is bridging across wires. Closely spaced solid wood slats (about 3" or less clear gap, with real center support to the floor) are the safer long-term pattern for all-latex.
For Hs22’s follow-up: if the KD-style slats are flexing, the problem is often the frame under them (thin center bar, no floor contact, or metal rails that don’t hold the slat ends well) as much as the slats themselves. Stacking another flexible layer on a weak frame usually doesn’t fix it. Options that tend to work:
- Sturdier foundation with thick, tight wood slats and center legs to the floor
- Replace the whole support with a solid-wood platform/slat system designed for latex
- Floor test overnight — if the mattress feels better on the floor, the foundation was the weak link
We go the metal-free solid-wood route with a movable slat system under VitaTalalay latex (wool + organic cotton), because the base is part of how the bed is meant to feel — not an afterthought. Not pitching that as the only answer; Terra-class foundations are also what many people here use when they want a tank-like fixed base. Happy to talk spacing / wood vs metal if you share what frame you’ve got now.
Quick question: for someone leaning toward a hybrid or innerspring rather than all-latex, does the slat spacing/center support advice still apply the same way, or does it matter less once there’s a coil layer doing some of that work?
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It absolutely does matter.. This is an area you cannot afford to skimp out on
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Hi WoM,
The general consensus is that if you are using a slatted bed frame foundation, the characteristics should be as follows:
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Slat Spacing: Less than 3", preferably 2–2.5"
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Slat Width: 2–3"
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Slat Thickness: 3/4" or more, unless the wood being used is extremely rigid.
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Solid Platform: A solid, non-flexing platform is fine.
The material of the mattress matters, and whether it has a substantial base layer is meaningful.
With a hybrid or innerspring, the coil unit obviously provides a significant amount of structural support within the mattress, so the foundation isn’t doing all of the work. However, that doesn’t make the support underneath the mattress irrelevant. The mattress still needs reasonably consistent support across its surface.
For example, if the slat spacing is excessive, the mattress can flex down into the spaces between the slats. This is particularly relevant with the foam layers above the coil unit. The coils may be perfectly capable of supporting the sleeper, but they are still sitting on a foundation that is allowing portions of the mattress to move unsupported between the slats.
Center support is important for the same basic reason. The larger the mattress, the more important it becomes that the foundation itself isn’t flexing or allowing the center of the mattress to sag. So center support legs are important too.
So while the exact requirements can vary somewhat with the construction of the mattress, I wouldn’t consider a hybrid or innerspring a reason to relax the foundation requirements. The manufacturer’s stated maximum slat spacing is just that, a maximum tolerance (that I personally do not always agree with), not necessarily an optimal specification. If you can use closer spacing, adequate slat width and thickness, and good center support, exceeding the manufacturer’s minimum foundation requirements in that direction is simply better practice and gives the mattress a more consistently supported surface. Additionally, various manufacturer’s have different requirements. If something should change during your trial period, or shortly after, like you just want something different, an injury, or any other reason for changing, you know you have a foundation that will support just about anything.
Maverick
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Hi worldofmattress_01 — good question.
A coil unit can carry more of the span than all-latex, so a hybrid or innerspring is often a bit more forgiving of a mediocre base than a pure latex core. That said, the foundation still matters. Wide gaps, a soft box spring, or a missing/weak center support can still show up as saggy feel, early comfort-layer wear, or edge issues — especially if there’s foam or latex on top of the coils.
Practical take: keep firm, even support and a solid center rail (with legs to the floor on queen/king). Tight wood slats or a solid platform still help. Coils don’t make spacing irrelevant; they just make a bad base hurt a little slower.
— Hendrik, CBH Wood Furniture / Swiss Dream Beds
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Have you looked at the terra foundation with legs, well over 3000 lbs of support. If placing a knock down foundation onto a metal bed frame then the foundation is now out of the equation since your now depending on support from the metal bed frame.
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That makes sense, thanks. So it sounds like regardless of what mattress I end up with, getting a solid foundation with real center support is worth doing anyway rather than hoping the mattress type covers for it.
I’ll factor that into the foundation replacement along with whatever I pick for the mattress itself.
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