Bunk beds, shorty beds and cabin beds do not always use a current standard UK mattress size. The sleeping platform may be shorter, narrower or limited by guard rails and built in furniture. The All Foam custom mattress builder accepts rectangular made to measure dimensions, giving customers control over finished width, length, thickness and foam construction.
Accurate measurement is essential. A custom mattress is made from the dimensions selected, so the bed frame, available depth and manufacturer instructions should be checked before ordering.
Start with the bed manufacturer information
Look for a label, manual or product page that states the intended mattress size and maximum permitted depth. This is especially important on an upper bunk because the mattress height affects the usable guard rail above the sleeping surface.
Do not choose a deeper mattress simply because more depth sounds more comfortable. The bed manufacturer determines the safe mattress limit for that frame.
If the information is missing, contact the bed supplier or manufacturer. All Foam can help with foam choices, but it cannot confirm the safety limits of an unknown bed frame.
Measure the actual mattress platform
Remove the existing mattress and measure the supporting area inside the frame. Record the finished width and length in centimetres.
Measure between the points that will contain the mattress, not across decorative outer rails. Check both ends and several points along the length because handmade, older and timber frames may not be square.
Use the smallest measurement where the frame varies. A mattress that is slightly too large can bow, compress against the sides or become difficult to remove.
Do not copy an old mattress automatically
An old mattress may have spread, shrunk or changed shape. Its label may also describe a nominal size rather than its current dimensions.
Measure the platform first, then compare it with the old mattress. The old product can help confirm practical fit, but it should not override the frame measurement.
If the old mattress fitted badly, copying it will repeat the problem.
Check ladder, rail and drawer clearances
Bunk and cabin beds can have more restrictions than a normal open bed frame. Check whether the mattress needs to clear:
- ladder fixings
- guard rail posts
- raised corner blocks
- side lips
- drawer units
- pull out sections
- hinges or folding panels
- built in shelves
The online builder produces a rectangle. If the space needs cut outs, curves, tapers or an unusual shape, a full size template is required and the customer should contact All Foam before ordering.
Measure the available mattress depth
The builder accepts whole inch thicknesses from 1 to 10 inches for custom rectangular sizes. The correct depth is controlled first by the bed frame and any stated maximum.
Measure from the supporting platform to the highest permitted sleeping surface. On an upper bunk, leave the guard rail clearance required by the bed manufacturer.
On a cabin bed or day bed, also consider sitting height, access and nearby shelves. A deeper mattress can reduce headroom or make the bed harder to use as seating.
Shorty beds need exact length measurements
The term shorty bed is used for several non standard sizes. It does not guarantee one fixed length or width.
Some short beds are designed for children, compact rooms or cabin furniture. Others are older frames with dimensions that do not match current labels.
Enter the finished centimetre dimensions measured from the actual platform. Do not order from the name alone.
One layer for thinner mattresses
Custom mattresses below 4 inches use one foam layer. This can suit a bed with a strict depth restriction where a simple foam pad is required.
Memory foam is not available as a one layer custom mattress because it is restricted to the top layer of a two or three layer construction. A one layer mattress must use one of the supportive foam grades offered by the builder.
A thin mattress will feel more influenced by the bed base. The platform should be level, supportive and suitable for the chosen foam.
One or two layers from 4 to 7 inches
From 4 to 7 inches, the builder allows either one or two layers.
A one layer construction provides a straightforward single grade mattress. A two layer build combines a support base with an upper comfort layer.
The support base is normally thicker than the comfort layer. The approved exception is a balanced 2 inch base with a 2 inch comfort layer in a 4 inch mattress.
For a bunk or shorty bed, the two layer option can provide more control over surface feel while staying within a restricted total depth.
Up to three layers from 8 to 10 inches
At 8, 9 or 10 inches, the builder allows one, two or three layers.
A three layer construction can combine a substantial support base, a middle transition layer and a top comfort layer. The base remains thicker than the middle and top layers combined.
This depth may suit a lower bunk, cabin bed or full height frame where the manufacturer permits it. It may be unsuitable for an upper bunk with limited guard rail clearance.
Always confirm the frame limit before choosing the layer count.
Choosing the support foam
The base layer provides most of the mattress structure. All Foam offers several grades with different firmness and recovery characteristics.
Medium foam gives a more balanced feel. High foam provides firmer support. Severe Very Firm is the firmest option in the builder. Reflex Medium has quicker recovery with a medium feel, while Reflex Grey is a firmer responsive grade.
Choose the support foam by the preferred feel, user weight, mattress depth and how often the bed will be used. A guest bunk used occasionally may have different priorities from a main bed used every night.
Choosing the top comfort layer
The upper layer changes the immediate surface feel. Reflex Medium provides a resilient medium response. Other supportive grades can create a firmer surface.
Memory foam is available only as the top layer of a two or three layer construction. It responds more slowly and follows the body more closely.
Do not place memory foam in the base or middle layer. The live builder removes it from those selections and the server checks the same rule when the mattress is added to the basket.
Consider who will use the bed
The mattress should suit the person using it, not only the frame. Consider body weight, preferred firmness, sleeping position and whether the bed is for regular or occasional use.
A very firm thin mattress may feel different from the same foam grade in a deeper construction. Thickness and layer arrangement influence the final result.
For children, follow the bed and mattress guidance supplied by the frame manufacturer. Do not rely on a general age label or assume that one foam grade suits every user.
Check the supporting base
Foam needs an even, supportive surface. Inspect slats, boards and centre rails before measuring.
Replace damaged slats and secure loose fittings. Check that gaps and ventilation arrangements are suitable for a foam mattress.
A new made to measure mattress cannot correct a bowed platform or unstable frame.
Plan bedding and the final cover
A fitted cover is included when a standard size is configured at 8, 9 or 10 inches. Made to measure rectangular foam is supplied without a custom made cover.
For a custom bunk or shorty mattress, plan how the foam will be covered and protected. Existing fitted bedding may not match the non standard length or depth.
Measure the finished foam dimensions when sourcing a separate cover. Covers, seams and fabric tension can affect fit, so do not assume an empty old cover gives the exact foam size.
Check access before ordering one piece
Measure doors, staircases, landings and the bed opening. A compact room can make a long one piece mattress difficult to manoeuvre even when the finished size fits the frame.
The builder prices one rectangular mattress. If the application may need a split construction for access, contact All Foam before ordering rather than submitting two assumptions separately.
A clear drawing with dimensions and orientation helps explain the space.
Review every builder selection
The custom builder begins with Please select on each option. Choose the size type, enter custom width and length, select the whole inch thickness, choose the layer count, select an available split and then choose every active foam grade.
The price and Add to Basket button remain unavailable until the configuration is complete. Review the summary before adding it to the basket.
Custom mattresses are normally dispatched within 2 working days. Delivery time begins after dispatch and depends on destination and service.
Common measuring mistakes
Avoid these problems:
- ordering from the term shorty without measuring
- using the old mattress as the only reference
- measuring the outside of the bed frame
- ignoring the manufacturer maximum mattress depth
- forgetting ladder and guard rail fittings
- assuming the opening is square
- choosing a shaped mattress through the rectangular builder
- overlooking room and staircase access
- expecting a made to measure cover with a custom rectangle
- selecting firmness without considering total thickness
Information to confirm before ordering
Record:
- finished width and length in centimetres
- permitted total mattress depth
- whether the frame is rectangular
- any posts, rails or fittings near the mattress
- the condition of the supporting base
- regular or occasional use
- preferred firmness and response
- required number of layers
- access into the room and bed frame
- the plan for a separate cover and bedding
Final guidance
A custom mattress for a bunk bed, shorty bed or cabin bed should begin with the frame dimensions and the manufacturer depth limit. Measure the clear platform, check rails and fittings, and confirm that the rectangle can be installed and removed.
Use one layer below 4 inches, one or two layers from 4 to 7 inches, and up to three layers from 8 to 10 inches where the frame permits. Keep the base as the main support layer and use memory foam only as an upper comfort layer in a two or three layer build.
Careful measuring and the builder summary are more reliable than ordering from a bed name alone.