The All Foam custom mattress builder includes two different ordering routes. Standard UK sizes include a fitted cover automatically. Custom rectangular mattresses are supplied without a made-to-measure cover, allowing the foam construction to be ordered for an existing suitable cover or a project that will be finished separately.
This distinction matters because the entered width, length and thickness must describe the foam that will fit the finished space. A separate cover adds seams, fabric tension and a small amount of finished bulk around the foam.
Quick answer
Standard-size mattresses selected in the builder include a fitted cover. Custom rectangular mattresses are supplied without a made-to-measure cover and are normally dispatched within 2 working days.
Why custom rectangular foam is supplied without a cover
The online custom-size option is designed for a rectangular foam mattress core made to the width, length, thickness and layer construction entered by the customer. It is suitable when:
- the new foam will fit an existing mattress cover
- an upholsterer will finish the project
- a specialist cover will be sourced separately
- the foam is being used as an internal component
- the required size is not a standard UK mattress dimension
The builder does not offer a made-to-measure cover option for custom rectangular sizes. The basket price therefore covers the selected foam layers and customisation charge rather than a separately manufactured cover.
Standard sizes still include a fitted cover
When Single, Double, King Size or Super King is selected in the builder, the configuration includes a fitted cover automatically. Standard sizes are available at 8, 9 or 10 inches and use the normal standard-size construction rules shown on the page.
If custom measurements exactly match a standard mattress size at an 8, 9 or 10 inch depth, select the named standard size instead. This keeps the order aligned with the standard-size product and its included cover.
Measure the foam core, not an empty cover laid flat
An empty fabric cover can be difficult to measure accurately. Seams, stretch and previous use can change its apparent dimensions. Measure the internal space the foam must occupy rather than relying only on the outside edge of the empty cover.
For an existing zip cover:
1. Open the cover fully and place it on a level surface. 2. Check whether the fabric has stretched, shrunk or become distorted. 3. Measure the internal width and length at several points. 4. Check the intended foam depth without pulling the fabric tight. 5. Use the smallest practical measurement where the cover is uneven. 6. Contact All Foam when the fit has almost no tolerance.
The foam measuring guide provides a fuller checklist for replacement foam and finished spaces.
Check the old foam before copying it
Old foam is not always a reliable template. It may have:
- compressed permanently
- rounded at the edges
- shrunk slightly
- torn or crumbled
- absorbed moisture
- stretched the surrounding cover
Copying a damaged foam core can reproduce the wrong fit. Compare the old foam with the cover, bed frame and intended finished dimensions before entering the order.
Allow for seams and fabric tension
A separate cover may feel smaller than its stated dimensions because the seams and fabric tension hold the foam firmly. This can be useful, but an excessively tight cover may round the mattress edges or compress a softer comfort layer.
A loose cover can crease, move or create an uneven sleeping surface. The correct fit should hold the foam securely without forcing it into a significantly smaller space.
When a cover is being made by another supplier, ask whether the measurements they require describe:
- the foam core
- the finished outside size
- the seam-to-seam internal size
Do not assume these measurements are interchangeable.
Does a separate cover affect the mattress feel?
Yes. A thick, quilted or tightly fitted cover may reduce how closely a soft upper layer follows the body. A flexible cover allows more of the foam response to be felt.
The cover should suit the selected construction. Memory foam usually benefits from a flexible surface that does not prevent contouring. Firmer support constructions may feel less affected, although fabric and quilting still influence the initial surface feel.
Protect uncovered foam during handling
Custom rectangular foam should be kept protected until it is fitted into its final cover or finished installation. Uncovered foam can be marked or damaged by dirt, body oils, sharp objects, direct sunlight and rough handling.
Keep the foam wrapped until the work area is clean. Support large pieces across their width rather than pulling them by one corner. Avoid forcing the foam through a partly opened zip because this can tear the edge or strain the cover seams.
Day beds, window seats and guest beds
Custom rectangular foam is often ordered for day beds, window seats and guest spaces. The final finishing method depends on the project.
An existing removable cover may be suitable for a guest mattress. A window seat may be finished by an upholsterer using decorative fabric. A day bed used regularly for sleeping should have a suitable mattress cover and protector arranged separately.
The day bed and guest mattress guide explains how to plan dimensions, access, ventilation and the intended use.
Antique and non-standard bed frames
Older bed frames may be narrower, shorter or less square than modern UK sizes. Measure the actual support area and check the frame at more than one point.
Custom rectangular foam can suit a non-standard frame, but shaped corners, curves and cut-outs require a template and should be discussed with All Foam before ordering. The antique bed mattress guide covers these checks in more detail.
Cleaning and care
Follow the care instructions supplied with the separate cover. Do not assume every zip cover can be machine washed or tumble dried. A cover must be completely dry before it is refitted around foam.
A mattress protector sits above the mattress cover and helps reduce exposure to spills and everyday dirt. It does not replace the cover that encloses the foam core.
Keep the foam dry and use it on a level, supportive and ventilated base. Check for condensation in caravans, boats, storage beds and areas against cold external walls.
Dispatch time for custom mattresses
Custom mattresses are normally dispatched within 2 working days. Delivery begins after dispatch and depends on the delivery service, parcel size and destination.
Review the delivery information for regional charges and courier guidance. Contact All Foam before ordering when a fixed deadline is important.
What to check before adding to the basket
Review the completed builder summary and confirm:
- the correct standard or custom size is selected
- custom width and length are entered in centimetres
- the total thickness is correct
- the selected layer count is allowed at that thickness
- every foam grade is correct
- the layer split matches the intended construction
- the quantity is correct
- the live price matches the displayed configuration
For a custom rectangular mattress, remember that the order is supplied without a made-to-measure cover. The basket description should show the size, thickness and foam construction rather than a cover choice.
When to contact All Foam before ordering
Contact the team when:
- the mattress needs rounded corners, curves or cut-outs
- the bed frame is not square
- an existing cover is difficult to measure
- the foam must fit with almost no tolerance
- the project needs split sections
- access through a hatch, stairway or narrow door is restricted
- you are unsure which foam should be used for the base or comfort layer
Photographs and a clear drawing can help explain the project. A physical template may still be required where shape accuracy matters.
Order with the finished use in mind
Choose a standard size when the named UK dimensions suit the bed and you need the fitted cover included with the mattress. Choose the custom rectangular option when the foam must be made to specific dimensions and will be fitted into an existing suitable cover or finished separately.
Measure the finished space carefully, account for the way the separate cover will fit and review the complete construction before checkout. Custom mattresses are normally dispatched within 2 working days.
