Can I Put a Regular Mattress on a Bunk Bed?
Sometimes, yes. If your guardrail has enough clearance for a standard single's height, a regular mattress is fine and you do not need a bunk-specific one. The mattress that is wrong for a bunk is not "a normal mattress", it is one that is too thick for that specific guardrail. This article is the honest yes and no case, side by side, not a blanket rule either way.
The rule that decides it
EN 747-1:2024, the bunk bed safety standard most South African-made frames are built to, requires at least 160mm (16cm) of clearance between the top of the mattress and the top of the guardrail. Whether a regular mattress is fine depends entirely on whether its thickness fits inside that clearance, not on whether it is labelled "regular" or "bunk-specific".
Yes, a regular mattress is fine, when...
- Your guardrail gives 34cm or more of clearance above the base, which comfortably fits a standard 18cm mattress.
- You have actually measured the guardrail yourself, not assumed it based on how the bed "looks".
- You are not adding a topper that would push the total height over the guardrail's clearance.
Our own Comfort Foam standard build, 18cm total, R2,399 for a Single, is a genuine "regular" mattress in every sense (same range sold for standard beds), and it is entirely appropriate for a bunk with sufficient guardrail clearance.
No, a regular mattress is not fine, when...
- Your guardrail clearance is under 34cm, meaning an 18cm mattress leaves less than the required 16cm gap.
- You have not measured at all and are relying on the mattress "fitting" the frame's length and width, which says nothing about the vertical clearance.
- You are stacking a mattress and a topper without re-checking the combined height against the guardrail.
In this case, the fix is not to avoid all regular mattresses, it is to choose a thinner build. Our Comfort Foam 150mm Bunk Bed Height exists exactly for this case: same 50 kg/m3 foam, same R2,399 price, same 3 year warranty, just 15cm instead of 18cm, built to clear guardrails down to 31cm.
| Your guardrail clearance | Verdict |
|---|---|
| 34cm or more | A regular 18cm mattress is fine. No bunk-specific mattress needed. |
| 31cm to 33cm | Choose the 150mm Bunk Bed Height instead. A regular 18cm mattress would exceed the clearance. |
| Under 31cm | Neither of our current heights is guaranteed to fit. Contact us before ordering. |
A worked example of each case
The "yes" case
A guardrail measures 38cm above the base. Subtract 16cm and you have 22cm of safe clearance. A regular 18cm mattress, bought for any standard bed and moved onto this bunk, fits with 4cm to spare. There is nothing wrong with using it here; buying a separate "bunk mattress" would not add any safety benefit in this specific case.
The "no" case
A guardrail on a different bunk measures 30cm above the base. Subtract 16cm and you have 14cm of safe clearance. That same regular 18cm mattress is now 4cm too thick, and using it would leave less than the required guardrail clearance, defeating the guardrail's purpose even though the mattress "fits" the bed's length and width perfectly.
Reframing "wrong mattress"
It is tempting to think of this as "normal mattress" versus "special bunk mattress", as if there were two different products. There is really one variable: thickness versus your guardrail's clearance. A mattress can be perfectly ordinary in every other respect, foam grade, cover, warranty, and still be the wrong choice for a specific bunk simply because it is too thick for that guardrail. Equally, a mattress can be marketed as "for bunk beds" and still be wrong if it is thicker than your guardrail allows.
Frequently asked questions
Can I use a normal mattress on the top bunk?
Yes, if your guardrail gives enough clearance for its thickness (at least 16cm above the mattress top, per EN 747-1:2024). It is not automatically wrong just because it is not labelled bunk-specific.
Can I use a normal mattress on the bottom bunk?
Yes, always. The guardrail clearance rule only applies to the top bunk, since it exists to stop a fall from height.
What makes a mattress "wrong" for a bunk bed?
Being too thick for that specific guardrail's clearance, not being a "normal" mattress as such.
What should I buy if my guardrail is tight?
Our Comfort Foam 150mm Bunk Bed Height, built at 15cm specifically to clear tighter guardrails, same R2,399 price as our standard build.
Related: Best mattress for bunk beds, the full guide · What thickness should a bunk bed mattress be · Landing page: both heights side by side
Reviewed by Andries Taljaard, Founder of Mr Mattress.