Bunk Bed Guide
Types

Trundle beds and sleepovers

A trundle is a low bed on castors that rolls out from under a bunk or cabin for a guest. It saves floor during the day, not at night, and it only works with a mattress the maker says fits it.

By the Bunk Bed Guide team · Updated 13 November 2026

What a trundle is

Shops use trundle, pull-out bed and guest bed for a low frame that sits under the main bed and rolls out. Some are part of the bunk or cabin, some are sold as an add-on for a specific model. It is different from a storage drawer. Cabin beds and storage underneath covers drawers and dens. A trundle is a sleeping surface, so it needs a proper mattress and enough clear floor to pull out fully.

Floor space at night

When the trundle is out, the bed takes far more floor. How much floor space does a bunk bed need? shows how to plan the footprint from the maker’s overall sizes. Add the full pulled-out trundle in front of the bed, and check that the door still opens and the ladder still lands on clear floor. If the trundle blocks the ladder, the child on top has no safe way down in the night.

Check the gap under the bed as well. A thick carpet or a skirting board can stop the castors before the trundle is fully out.

The mattress that fits

A trundle frame is shallow, so it usually takes a thinner mattress than the main bed. Use the size and depth the maker gives for the trundle itself. A mattress that is too deep stops it sliding back under, and one that is too long will not sit flat. UK mattress sizes for bunks and shorties explains why a single, a small single and a shorty mattress are not interchangeable.

Keep the trundle for sleepovers and occasional guests unless the maker says it is suitable for nightly use.

Questions people ask

Can I add a trundle to any bunk bed?

Only one the maker sells or approves for that model. The gap under the lower bed and the side rails vary.

Can a younger child sleep on the trundle?

A trundle sits at floor level, so it is not the upper bed that carries the under-six warning. Follow the maker’s own guidance for the trundle.

Sources

Opened 13 November 2026. The maker’s sheet and the mark on the bed take precedence.

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    Types

    Bunk, cabin, mid sleeper or high sleeper

    A bunk stacks two beds. A mid sleeper is a lower raised bed with space underneath. A high sleeper is one high bed, often with a desk. A cabin is a raised bed with a den or storage. The upper bed of anything with a base 600 mm or more off the floor carries the under-six warning.

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    Shorty bunk beds for smaller rooms

    A shorty bunk is a lower, usually shorter bunk for a tight ceiling. Boori’s typical mattress is about 75 × 175 cm, and their typical top surface is about 120–130 cm. Confirm both figures on the model you buy.

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    High sleeper with a desk for teens

    A high sleeper puts one bed at the ceiling and a desk underneath. The Ocean listing is 178.5 cm tall before the mattress. You still need sitting headroom, a chair that pulls out, and the maker’s weight limit if they publish one.