Wall beds create useful sleeping space in rooms that serve more than one purpose. The All Foam custom mattress builder can make rectangular foam mattresses to non-standard sizes, but a wall bed or Murphy bed has mechanical limits that must be checked before choosing the mattress.
Unlike a conventional bed, the mattress may spend long periods stored vertically inside a cabinet. Depth, overall dimensions, mattress retention and the lifting mechanism therefore matter alongside comfort and firmness.
What is a wall bed or Murphy bed?
A wall bed is a bed frame designed to lift into a vertical or horizontal storage position when not in use. Murphy bed is a widely used name for this type of fold-away bed.
Some systems disappear into a cabinet. Others combine the bed with shelving, a desk or a sofa.
The mattress requirements are set by the particular mechanism, so do not rely on a general wall-bed size guide without checking the manufacturer's specification.
Read the wall-bed specification before measuring
Look for the installation manual, product label or manufacturer's website.
You need to know:
- intended mattress width and length
- minimum or maximum mattress thickness
- permitted mattress weight
- how the mattress is retained when vertical
- whether a specific mattress construction is required
- whether bedding can remain on the bed during storage
- clearance inside the cabinet
A custom mattress should fit within those limits rather than forcing the mechanism to accommodate a different product.
Measure the mattress platform with the bed open
Lower the bed fully onto its normal supports and measure the usable sleeping platform.
Record the finished mattress width and length in centimetres.
Measure more than once if the frame is handmade or the mattress area is enclosed by side rails. The dimensions should describe the mattress space, not the outside cabinet.
If the platform is rectangular, the All Foam builder can accept a custom rectangular size. If it has curves, clipped corners or fixed cut-outs, contact All Foam because shaped mattresses require a template.
Our non-standard mattress sizes guide explains the difference between an unusual rectangle and a genuinely shaped mattress.
Mattress depth can affect whether the bed closes
A wall-bed cabinet has a limited internal depth.
A mattress that is too thick can press against the cabinet, interfere with shelves or stop the locking system from engaging correctly.
The All Foam custom builder accepts whole-inch thicknesses from 1 to 10 inches, but the frame manufacturer determines which of those depths are suitable for the particular wall bed.
Do not select a deeper mattress only because it offers more possible layers.
Weight matters to the lifting mechanism
Wall beds use springs, pistons or another counterbalance system to help lift and lower the bed.
The mechanism may be designed around a particular mattress weight range.
A replacement mattress that is substantially different from the intended specification can change how the bed operates.
Check the manufacturer's mattress weight requirement before ordering. All Foam can explain the foam construction, but the wall-bed manufacturer is responsible for the safe operating limits of its mechanism.
Check how the mattress is retained vertically
When the bed is raised, the mattress should stay in the position intended by the frame design.
Wall beds may use:
- straps
- bars
- cabinet lips
- fitted retainers
- dedicated mattress enclosures
Inspect these components before measuring. A missing or damaged retainer should be repaired rather than relying on mattress friction to hold the foam in place.
A rectangular custom mattress can solve non-standard cabinet sizes
Imported wall beds, handmade installations and older mechanisms may not match current UK Single, Double, King Size or Super King dimensions.
If the mattress platform is genuinely rectangular but uses different measurements, a made-to-measure foam mattress can avoid forcing the nearest standard size into the frame.
Our UK mattress sizes guide lists the normal All Foam standard dimensions so you can check whether custom sizing is actually necessary.
Choose thickness from the mechanism first, then the layer build
Once the permitted mattress depth is known, the All Foam builder limits the layer choices accordingly.
Custom mattresses below 4 inches use one layer.
From 4 to 7 inches, one or two layers are available.
At 8, 9 or 10 inches, one, two or three layers are available.
The support base remains the main part of the mattress construction. The specific 4-inch 2 plus 2 build is the permitted balanced exception.
These construction rules do not override the wall-bed manufacturer's maximum mattress depth.
One-layer wall-bed mattresses
A one-layer mattress is the simplest construction and uses the full depth as one supportive foam grade.
This can be relevant where the wall-bed cabinet has limited clearance, but a thin mattress must still provide a suitable sleeping surface and comply with the frame instructions.
The bed base will have a greater influence on the feel of a thin mattress.
Check that the platform is level and evenly supportive before ordering.
Two-layer constructions
A two-layer custom mattress combines a support base with an upper comfort layer.
This gives more control over surface feel when the wall-bed mechanism permits enough depth.
Memory foam can be selected only as the top layer in a suitable two or three layer construction. It cannot be used as the support base or as a single-layer mattress.
Our how many foam layers guide explains why the support section remains the foundation of the build.
Three-layer constructions need sufficient cabinet clearance
At 8, 9 or 10 inches, a three-layer construction may be available in the online builder.
Whether that depth is suitable for a wall bed is a separate question. Many cabinets have strict depth and weight requirements.
Do not assume that an 8 or 10 inch mattress will fit because the open bed platform appears large enough. Measure the closed cabinet clearance and follow the mechanism specification.
Check the bed base and support system
Wall beds can use slats, panels or other proprietary support systems.
Inspect:
- slat condition
- centre rails
- fixing points
- platform level
- missing supports
- damage around hinges
A custom mattress cannot compensate for a bowed or unstable base.
If the support system has changed from the original wall-bed design, ask the manufacturer whether it remains suitable before choosing a mattress.
Consider ventilation during vertical storage
A wall bed can spend much of the day closed.
Follow the furniture manufacturer's guidance on ventilation, bedding and storage. Allow the mattress and bedding to air as recommended before closing the cabinet, particularly after use.
Do not block ventilation openings built into the wall-bed system.
If the room has persistent damp or condensation, address the source rather than expecting a different foam grade to solve it.
When to contact All Foam before ordering
Contact the team when:
- the mattress is not rectangular
- the wall bed requires a shaped corner or cut-out
- the frame specification is unclear
- the mechanism has an unusual folding requirement
- the intended mattress depth is tightly restricted
- you need help comparing suitable foam grades
Shaped mattresses require a full-size template. Our custom mattress template guide explains how to prepare the outline before discussing the job.
Quick answers about wall-bed mattresses
Can I use a custom foam mattress in a wall bed?
A custom rectangular foam mattress can be considered when it fits the wall-bed manufacturer's requirements for size, depth, weight and mattress construction. Check the mechanism specification first.
How thick should a wall-bed mattress be?
There is no universal depth. Use the minimum and maximum thickness stated by the wall-bed manufacturer and measure the cabinet clearance before ordering.
Can I order a non-standard wall-bed mattress size?
Yes, the All Foam custom builder accepts rectangular made-to-measure dimensions. If the mattress needs curves, clipped corners or cut-outs, contact All Foam because a template is required.
Does mattress weight matter in a Murphy bed?
It can. The lifting or counterbalance mechanism may be designed for a particular mattress weight range, so follow the manufacturer's requirements.
Can memory foam be used in a custom wall-bed mattress?
In the All Foam builder, memory foam is available only as the top layer of a suitable two or three layer construction. The wall-bed mechanism must also permit the resulting depth and construction.
Wall-bed mattress checklist
Before placing an order, confirm:
- the wall-bed manufacturer and model have been identified where possible
- the bed is installed and working correctly
- the mattress platform has been measured while fully open
- maximum mattress depth is known
- any mattress weight requirement has been checked
- cabinet closing clearance is sufficient
- mattress retainers are present and working
- bedding storage requirements are understood
- the support platform is level and sound
- the requested mattress is rectangular if using the online builder
- shaped work has been discussed with All Foam
- layer count follows the selected mattress thickness
- memory foam, if chosen, is top layer only
A wall bed can make excellent use of a compact or multipurpose room, but the mechanism comes first. Measure the actual platform, follow the cabinet's mattress limits and then use the All Foam custom mattress builder to configure a compatible rectangular size and foam construction.
