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It claims to be the ‘firmest mattress ever’ but is that true?
But despite the unyielding feel, the Plank delivers more comfort than you might expect.
The Plank Firm, with the extra firm side facing upwards(Image credit: Future)
What’s more, it’s a flippable mattress, with one side delivering slightly more contouring.
The Plank Firm also comes with a 120-night trial, a 10-year warranty, and free delivery.
Use it one way round, and you’ll be enjoying a firm surface.
The Plank Firm, with the extra firm side facing upwards(Image credit: Future)
Flip it the other way and you’ll have an extra firm mattress to rest on.
The firm side is likewise finished with a .75" quilted top.
If you need extra cooling, upgrade to a GlacioTex cover for both sides.
The Plank Firm, with the extra firm side facing upwards(Image credit: Future)
On the extra firm side, a continuous pattern stitch limits the loft for minimal padding.
Despite being double-sided, the Plank is relatively thin for a mattress.
It measures only 9 inches tall, slightly under the 10-inchmattress thicknesswe recommend for adults.
The Plank Firm, with the firm side facing upwards(Image credit: Future)
One side is extra firm, and it really does live up to its name.
That hardness does give the extra firm side a limited appeal.
Surprisingly, we also struggled to get comfortable when front-sleeping on the extra firm side.
(Image credit: Future)
Thebest mattresses for stomach sleepersare typically firm, but our testers found the Plank a bit too hard.
It pushes against the stomach, which might get uncomfortable after a big meal, for example.
For our testers, the extra firm side excelled at back sleeping.
(Image credit: Future)
The firm side is immediately softer but still quite solid.
Plank rates the Firm as an 8/10, and our testers agree.
However, those with a heavier build might appreciate the lack of deep sinkage.
We found back sleeping most comfortable on the extra firm side(Image credit: Future)
Our testers think the firm side appeals to front sleepers.
As for the extra firm side, the weight hardly sank.
We measured just a 1" drop at the side and only 1.5" at the corner.
There’s limited relief for side sleepers on the extra firm side(Image credit: Future)
Our objective testing backed this up the Plank Extra Firm has a secure and steady perimeter.
It’s so strong, you could comfortably use that side as a sofa.
When the weight dropped, we recorded the movement of the wine glass.
The extra firm side is perhaps too firm for front sleeping(Image credit: Future)
On both sides, the glass was still at 25", and wobbled slightly from 12" away.
From 4" away, the glass fell over on the firm side.
On the extra firm side, the glass stayed upright but did fall when we later repeated the test.
There was minimal sink at the edges and corner of the extra firm side(Image credit: Future)
Our subjective tests showed similar results.
However, we expect that the firm surface and lack of sink prevent the Plank Firm from trapping heat.
Very hot sleepers should consider upgrading to the GlacoiTex cooling cover.
Our testers felt comfortable sitting on all sides of the Plank Firm(Image credit: Future)
To learn how a GlacioTex cooling cover performs, check out ourBrooklyn Bedding Aurora Luxe mattress review.
Should you buy the Plank Firm mattress?
You won’t feel your hips or lower back sink out of alignment.
The weight sank more on the firm side, but stayed well balanced(Image credit: Future)
Your support needs change:Double-sided mattresses allow you to change the feel depending on your needs.
This is particularly helpful if you have a reoccurring injury that might change what feel benefits you best.
You need strong edges:Sitting on the edge of the Plank on either side feels stable and secure.
We were impressed with the motion isolation on the extra firm side(Image credit: Future)
The firm side is less unyielding, but most side sleepers can expect an achy arm.
The one exception here is larger side sleepers, who may find the subtle contouring comfortable.
The firm side showed slightly more motion transfer(Image credit: Future)
Feeling the cover on the Plank Extra Firm(Image credit: Future)
Feeling the cover on the Plank Firm(Image credit: Future)
