A closed cell foam sheet can be useful in camping and outdoor projects because it has a firm structure and low water uptake, but that does not mean every polyethylene sheet is automatically a purpose-made sleeping mat. If you are searching for a closed cell foam camping mat, it is worth separating ground protection, comfort and thermal insulation before choosing material.
All Foam's AFP30 and AFP45 products are cross-linked polyethylene sheets intended for a range of packaging, lining, sealing and specialist uses. They can be cut for practical outdoor pads, but the current product information does not publish a camping R-value or certify either grade as a finished sleeping mat.
Quick answer: can closed cell foam be used as a camping mat?
Yes, closed cell polyethylene can be used for suitable ground pads, sitting mats, kneeling pads and some DIY camping mat projects. For overnight sleeping, however, warmth, comfort, flexibility, pack size and tested thermal performance all matter. A purpose-made camping mat with a published R-value may be the better choice when insulation from cold ground is important.
Why closed cell foam is used in camping mats
Purpose-made foam camping mats often use closed cell polyethylene because the enclosed cell structure can provide cushioning without absorbing water in the same way as open cell foam.
That basic material behaviour is useful outdoors. A mat may be placed on damp grass, tent flooring, soil or rough ground, so low water uptake and easy cleaning can be practical advantages.
Closed cell foam also does not rely on air valves or an inflatable chamber. A simple foam mat cannot suffer a puncture in the same way as an inflatable mat.
Those advantages explain why closed cell sleeping pads remain common, but the finished product still matters. Different camping mats use different foam formulations, surface patterns, thicknesses and reflective layers.
A plain AFP sheet should therefore be judged as a foam material, not assumed to perform exactly like a branded sleeping pad.
Closed cell vs open cell foam for camping
Open cell foam has a network of interconnected cells. It is usually softer and allows more air movement through the structure. In upholstery, that can create useful cushioning and comfort.
Closed cell foam has cells that are more enclosed. It is normally firmer, more resistant to water uptake and more structurally stable in sheet form.
For a ground-contact camping pad, those characteristics can be useful because the material is less likely to act like a sponge when placed on a damp surface.
For sleeping comfort, however, softness and pressure relief matter too. A firmer closed cell sheet may feel much harder than a mattress or self-inflating mat.
If you want the broader material comparison, see the open cell vs closed cell foam guide.
What is the difference between a foam camping mat and an All Foam AFP sheet?
A purpose-made camping mat is a finished outdoor product. It may have:
- a tested R-value
- textured or moulded surfaces
- reflective layers
- folds or roll-friendly geometry
- a stated packed size and weight
- product-specific durability information
AFP30 and AFP45 are general closed cell polyethylene sheets. They are sold by thickness and sheet size for fabrication and other applications.
The current All Foam product information does not provide a camping R-value, so we cannot state that a particular thickness will deliver a particular level of ground insulation.
That distinction matters. If you are camping in cold conditions where thermal performance is important, choose equipment with the appropriate tested information rather than estimating from foam thickness alone.
Where a closed cell sheet can be useful outdoors
Even when it is not being used as a primary sleeping mat, closed cell polyethylene can be useful around a campsite.
Possible non-safety-critical uses include:
- a sitting pad
- a kneeling pad for tent setup
- a protective layer beneath equipment
- a liner for a storage box
- a spacer between hard camping items
- a clean work surface for repairs
- a pad beneath a cooler, crate or other equipment
For these jobs, the main questions are usually size, stiffness, thickness and how much load the pad will take.
AFP30 or AFP45 for a camping pad?
AFP30 has a nominal density of 30 kg/m³ and is the lighter general-purpose grade in the current All Foam closed cell range.
AFP45 has a nominal density of 45 kg/m³ and greater load-bearing resistance. It is more relevant where the pad must resist more concentrated pressure or hold its shape under a heavier load.
For a simple sitting or kneeling pad, additional rigidity is not automatically an advantage. A denser grade can feel firmer.
The right choice depends on what the foam is supporting, not just the number in the grade name.
Read the AFP30 vs AFP45 guide if you want to compare density and compression behaviour in more detail.
How thick should a closed cell camping mat be?
There is no universal answer.
A thin sheet can separate equipment from a damp or abrasive surface without taking up much space. A thicker sheet provides more physical depth, but it also takes up more room and can feel more rigid depending on the material.
For an overnight sleeping mat, thickness alone is not enough to predict warmth. Thermal performance depends on the complete mat construction and material, which is why purpose-made sleeping mats are often sold with tested R-values.
All Foam does not currently publish a camping R-value for AFP30 or AFP45, so we would not recommend choosing a thickness from an assumed temperature rating.
Instead, decide what the sheet must do and measure the finished space if it is being cut to fit a tent, vehicle, storage area or equipment compartment.
Is closed cell foam waterproof for camping?
The answer depends on the exact grade.
All Foam describes AFP30 as waterproof and non-absorbent. AFP45 has a stated maximum water absorption of 1% by volume.
That makes both grades relevant when low water uptake is important, but the foam sheet is only one part of a camping setup. Water can still travel around edges, through seams in other materials, or collect between the sheet and the surface beneath it.
A dry-feeling foam surface also does not mean sleeping equipment, tent flooring or clothing will remain dry in every condition.
Can you put closed cell foam under an inflatable mat?
A closed cell layer can sometimes be used as a physical protector beneath another piece of camping equipment, but compatibility depends on the mat, tent floor, surface and manufacturer guidance.
The useful idea is separation. A foam sheet can create a barrier between a delicate item and a rough floor.
Do not assume that adding an untested foam layer automatically increases the R-value of a sleeping system by a known amount. Without product-specific thermal data, that number would be a guess.
Packability matters
A purpose-made roll mat or folding mat is designed around transport. General sheet foam may behave differently.
Before making a large camping pad from sheet material, consider:
- whether it needs to roll or fold
- the size of the vehicle or rucksack
- whether repeated tight bending will suit the material
- whether the edges need trimming
- how the pad will be stored between trips
AFP30 and AFP45 are stable cross-linked polyethylene sheets. They should not be assumed to pack like a lightweight camping mat simply because both products contain closed cell foam.
Comfort is different from insulation
This is one of the most useful distinctions when comparing camping mats.
A mat can provide some separation from the cold ground and still feel hard. Another mat can feel comfortable but offer insufficient insulation for the conditions.
A side sleeper may notice pressure at the shoulder and hip more than a back sleeper. A heavier camper may compress the same material more than a lighter camper.
For that reason, a DIY foam pad should be physically tested for comfort before being relied upon for a longer trip.
Cutting a simple closed cell ground pad
If you are making a utility pad rather than a certified sleeping product, start with the finished dimensions you actually need.
Mark the sheet carefully and use an appropriate sharp cutting tool on a protected surface. Keep cuts square if the pad needs to fit inside a box or recess.
Round corners can be useful where a sharp corner would catch on equipment, but the final shape is a practical choice rather than a performance requirement.
If multiple pieces are needed, test the layout before deciding whether they need to be fixed together.
The current AFP sheets are supplied unbacked. The foam without adhesive backing guide explains why removable pieces can be useful where cleaning or reconfiguration matters.
What should you check before choosing foam for camping?
Use a short checklist:
- Is the foam for sleeping, sitting, kneeling or equipment protection?
- Does the application need a tested R-value?
- How much comfort is required?
- Will the sheet be carried in a rucksack or vehicle?
- Does it need to roll or fold?
- Will it contact damp ground?
- How large does the finished pad need to be?
- Will concentrated loads sit on it?
Answering those questions usually makes the material choice clearer.
Quick answer: is AFP30 or AFP45 a replacement for a rated camping mat?
Not automatically. AFP30 and AFP45 are general cross-linked polyethylene foam sheets, and All Foam does not currently publish camping R-values for them. They can suit practical DIY ground pads and outdoor protection, but where overnight warmth is important, use a camping product with the performance information required for the conditions.
Related All Foam guides
Read the open cell vs closed cell foam guide for the basic material difference, compare AFP30 with AFP45, or explore more clever uses for closed cell foam sheets.
