Kids’ Sleep by Age: Mattress Heights, Firmness & Bunk-Bed Safety (HIBER Guide)

If you’re a Canadian parent shopping for a mattress for a bunk bed, it can feel like there are too many things to juggle: safety rails, ceiling height, mattress thickness, firmness, and your kid’s (very strong) opinions about “comfy vs. too hard.”

This guide breaks it all down by age and bunk type, so you can choose the safest, most supportive mattress for bunk bed Canada kids without second-guessing yourself.

We’ll cover:

• Ideal mattress heights for top and bottom bunks

• Firmness recommendations by age

• Safety rules for bunk beds (including guardrails and ladders)

• Where HIBER fits in as a safer, Canadian-made option

Why Mattress Choice Matters More on a Bunk Bed

On a regular bed, the wrong mattress usually means cranky mornings.
On a bunk bed, it can also affect fall risk, head clearance, and ladder safety.

The right kids’ mattress for bunk beds needs to:

• Stay low-profile on the top bunk so guardrails actually do their job

• Offer enough support for growing spines (especially for side and combo sleepers)

• Be breathable, because warm air rises and top bunks get hotter

• Handle the inevitable: sleepovers, jumping, and “reading forts”

This is where purpose-built kids’ mattresses like HIBER shine: they’re designed with lower profiles and medium-firm support ideal for bunk beds, trundles, and lofts.

Bunk Bed Basics: Safety First

Before you even think firmness, start with these bunk-bed safety fundamentals:

• Age for top bunk: Most experts recommend 6+ years for the upper bunk. Younger kids should stay on the lower bunk or a floor bed.

• Guardrails: Top bunks must have sturdy guardrails on all sides, with only a small gap for the ladder. The mattress should sit below the top of the rails, not flush with them.

• Mattress thickness:

  • Most bunk bed manufacturers recommend a 6–8 inch mattress for the top bunk.

  • Thicker mattresses can make guardrails less effective and increase the risk of rolling out.

• Ceiling clearance: Leave enough space above the mattress so your child can sit up without hitting their head usually at least 75–90 cm (30–36 inches).

• Ladder safety: Make sure the ladder is stable, firmly attached, and has non-slip rungs. Teach kids to climb facing the ladder, not jumping down.

When in doubt, always check the label on your bunk bed frame. It usually lists maximum mattress thickness for the top bunk and total weight limits.

Mattress Height & Firmness by Age

Every child is different, but here’s a practical, age-based guide for choosing a mattress for bunk bed Canada kids.

Ages 2–5: Lower Bunks & Floor Beds Only

At this age, safety = low to the ground.

• Recommended sleep setup:

  • Floor bed, daybed, or the bottom bunk only

  • Upper bunk is off-limits

• Mattress Height:

  • 6–8" is perfect for the bottom bunk, making it safe and easy to climb in and out.

• Firmness:

  • Medium-firm to support growing spines

  • Avoid ultra-plush beds that can make it harder for toddlers to move and self-adjust at night.

HIBER Tip: A lower-profile, medium-firm kids mattress like HIBER is ideal on the bottom bunk firm enough for support, comfy enough for story time snuggles.

Ages 6–9: Graduating to the Top Bunk

This is often when kids start campaigning hard for the “big kid” top bunk.

• Can they sleep on the top bunk?

  • Yes, if they’re 6+, confident climbing, and you’re comfortable with it.

• Mattress Height (Top Bunk):

  • Stick to 6–7" max for the top bunk, depending on your frame’s safety label.

  • This ensures the guardrails still sit well above the mattress surface.

• Mattress Height (Bottom Bunk):

  • 6–9" is fine, especially if you need extra comfort for a bigger child or an adult occasionally.

• Firmness:

  • Medium to medium-firm works best at this age

  • Most kids are combo sleepers (a mix of back, side, and tummy), so you want support plus a bit of pressure relief.

HIBER Fit:

• The HIBER kids’ mattress is designed to be low-profile and supportive, making it a strong candidate as a mattress for bunk bed Canada kids especially for top bunks where height matters.

Ages 10–13: Growth Spurts & Heavier Sleepers

Preteens start to look and sleep more like small adults. Their mattresses need to keep up.

• Top Bunk Use:

  • Still okay if your child is coordinated, follows ladder rules, and isn’t pushing the bed’s weight limit.

• Mattress Height:

  • Top bunk: stay at 6–8" (check the frame label).

  • Bottom bunk or trundle: 8–10" can be fine if there’s enough clearance.

• Firmness:

  • Medium-firm is a smart default.

  • Side sleepers may appreciate a bit more cushioning on top, but the core must still be supportive.

This is often the age where investing in a better-quality kids’ mattress for bunk beds pays off. Growth plates, posture, and sports recovery all depend on good sleep and proper spinal alignment.

Ages 14+: Teens, Guests & Multi-Use Bunks

By the time your child is a teenager, your “kids’ bunk bed” is often doing triple duty: teen hangout, guest bed, and sleepover fort.

• Top Bunk:

  • Many families start reserving the upper bunk for friends and occasional use as kids get taller and heavier.

• Mattress Height:

  • Top bunk: typically 6–8", staying within the frame’s safety specs.

  • Bottom bunk: 8–10" is ideal for teens or adults, as long as there is headroom.

• Firmness:

  • Medium or medium-firm still works best for most teens.

  • Look for mattresses with good support cores that won’t sag under adult weight.

If your teen’s bunk is doubling as a guest room, choosing a Canadian-made mattress for bunk bed Canada kids and adults gives you more durability and comfort for everyone.

Special Considerations for Canadian Homes

When choosing a mattress for bunk bed Canada kids, there are a few extra factors Canadian families often think about:

• Rooms that run hot or cold:

  • In older homes or upstairs rooms, temperatures can swing.

  • Look for breathable foams and covers that help regulate temperature, especially for the top bunk where warm air rises.

• Allergies & sensitivities:

  • Many Canadian families look for low-VOC, CertiPUR-US® certified foams and hypoallergenic covers to keep kids’ sleep environments cleaner.

• Small bedrooms & condos:

  • Bunk beds are space-savers. Low-profile mattresses keep rooms feeling open and help beds fit under sloped ceilings or bulkheads.

HIBER and Haven’s kids-focused designs are made with Canadian homes in mind: compact, supportive, and built to handle real life (not just Pinterest photos).

How to Check if a Mattress Is Safe for Your Bunk Bed

Before you click “add to cart,” run through this quick checklist:

1. Confirm the bed’s maximum mattress thickness

   • Look for a sticker or printed warning on the bunk frame.

   • If it says “Max 7" mattress on top bunk,” don’t go thicker than that no matter how luxe the pillowtop looks.

2. Measure guardrail height vs. mattress height

   • Once the mattress is on the top bunk, the guardrail should extend well above the surface (ideally 12+ cm / 5" or more).

   • If the mattress nearly covers the rail, it’s too thick for that frame.

3. Check weight limits

   • Consider your child, mattress, plus any “extras” (siblings, parents sitting for bedtime reading).

   • Choose a lighter, lower-profile mattress on top to stay under the max weight and keep the centre of gravity low.

4. Test ladder access

   • Make sure the mattress doesn’t block the ladder entrance.

   • Your child should be able to climb up and step onto the mattress without tripping over a high edge.

5. Do the wiggle test

   • Once the mattress is in place, have your child lie down and gently roll near the rails.

   • Check for any gaps or loose points where they could slip or get stuck.

Where HIBER Fits In: Designed with Bunks in Mind

HIBER was created exactly for scenarios like this: kids’ rooms, bunk beds, lofts, and tight spaces that still need great sleep, not just “good enough.”

Here’s why HIBER works so well as a mattress for bunk bed Canada kids:

• Low-profile height that stays within most bunk bed top-bunk limits

• Medium-firm support tailored for growing bodies

• Breathable, kid-friendly materials to help with hot sleepers on upper bunks

• Made-to-order in Canada, shipped fresh so you’re not getting a mattress that’s been vacuum-packed in a warehouse for months

Whether you’re outfitting a cottage bunk room, a condo kids’ room, or upgrading from toddler beds, a properly sized HIBER mattress can give you peace of mind and your kids better sleep.

Quick Reference: Bunk-Bed Mattress Cheat Sheet

Top Bunk (6+ years):

• Height: 6–8" (always follow frame’s max thickness)

• Firmness: Medium-firm

• Priority: Guardrail height + safe ladder access

Bottom Bunk (All ages):

• Height: 6–9" (you can go a bit thicker if there’s headroom)

• Firmness: Medium to medium-firm

• Priority: Easy in/out access, enough support for growing bodies

Trundle / Pull-Out Under Bunk:

• Height: Often 6–7" max

• Firmness: Medium

• Priority: Low profile to slide under the frame, comfortable enough for guests

Final Thoughts: Safety + Support = Better Canadian Sleep

Choosing a mattress for bunk bed Canada kids doesn’t have to feel like guesswork.

If you focus on:

• The right height for safety rails

• The right firmness for your child’s age and sleep style

• A Canadian-made kids’ mattress designed for bunks and small spaces

…you’ll end up with a setup that’s safe, supportive, and built for all the stories, sleepovers, and growth spurts ahead.