Rubber sheets - the big comparison

WKS Isotec Isolierungen GmbH
2021-03-08 13:47:00 /
Rubber sheets - the big comparison - Rubber panels- the ultimate comparison | Campervan | Motorhome

Rubber sheets - the ultimate comparison | Campervan | Motorhome

Christin Busch
Reading time approx. 8 minutes

You have decided to upgrade (your) campervan in order to be able to go on holiday flexibly and everywhere? Congratulations! But for many of those who extend their camper van themselves, the fun curve collapses in the search for the right insulation materials. There are heated discussions in forums about the "best" rubber panels, sometimes causing great confusion. Yet the insulation topic doesn't have to be so complicated.

In this article, we briefly present all the rubber sheets that are suitable for insulating car bodies and are available in our online shop. Further down in the article you will also find a table with all the data - short and sweet.

Graphic on the topic of rubber sheeting comparison with meme
Picture: Isotec Isolierungen GmbH; graphic used from

What are insulations for campers?

All insulation mats are based on flexible rubber and are therefore particularly suitable for insulating campers and other car bodies. Due to its low thermal conductivity, the material reduces thermal losses and prevents condensation. Most rubber sheets react self-extinguishing in the event of a fire, which can prevent a moderately severe disaster. In addition, all self-extinguishing rubber panels with Euroclass B/BL-s3, d0 are also suitable for commercial use. Some insulation mats also have integrated antimicrobial protection to reduce the penetration of water vapour. This reduces the risk of corrosion under the insulation and protects against mould growth.

Which rubber board does not smell unpleasant?

The fact is: everyone's perception is different and all rubber insulation can smell initially. Batches that have been recently produced tend to have a slightly stronger odour. Generous airing helps the unpleasant odour to dissipate quickly. In our experience, the intensity of the odour cannot be determined by the manufacturer, product or price.

Self-adhesive or non-self-adhesive?

Whether you order your rubber insulation in a self-adhesive or non-self-adhesive version is purely a matter of taste and should be decided individually depending on the project. The self-adhesive versions are definitely simpler and correspondingly more popular: you save yourself the additional special adhesive and a lot of stress, as the self-adhesive insulation mats are only cut to size and can be processed directly.

Do self-adhesive versions also hold when my camper is in the sun?

We are often asked whether the self-adhesive versions also stick at high temperatures. In short: Yes! The self-adhesive film on the back sticks even if the camper is exposed to direct sunlight for a long time. In fact, it sticks so well that it can sometimes be difficult to remove the insulation without leaving residue.

Which insulation thickness is best for my motorhome?

For all motorhome owners who prefer to use their van in latitudes such as Central and Southern Europe, a 19mm thick material is recommended. For colder regions such as Scandinavia, we advise a thicker insulation mat.
Note that you should plan at least one box of thinner material (6mm or 9mm) for door elements etc.

How do I recognise an original product?

Unfortunately, there are enough reports of experiences or forum posts on the Internet that only a cheap imitation was delivered instead of the original product ordered. Therefore, check the back of the rubber sheets. The manufacturer's name and product variant should be printed there. Only in the case of cut-to-size sheets can it happen that the printed part has been cut off.

Rubber sheets - the big comparison:

Armaflex® AF

Let's start with the bestseller from probably the best-known manufacturer (Armacell) for van insulation. Armaflex® AF is the "all-round carefree package" and impresses with its good insulation values and its value. The AF variant reacts self-extinguishing in case of fire. In addition, an antimicrobial protection, which Armacell calls Microban®, protects against corrosion and mould growth. The only disadvantage is the somewhat higher price, which is, however, justified by the product properties.

Armaflex self-adhesive in carton
Self-adhesive Armaflex with cardboard, Image: Armacell

Armaflex® XG

The properties of Armaflex XG from the same manufacturer can almost keep up with its big brother, Armaflex® AF. In terms of thermal conductivity, water diffusion resistance and fire behaviour, the XG variant is in no way inferior. This means that the insulation material is also approved for commercial use. However, the Armaflex® XG 19mm comes without the integrated mould protection.

Armaflex® ACE

The most favourably priced variant from Armacell is Armaflex® ACE. Visually, all three product series are identical, the technical values are only slightly worse, which is why it is not approved for commercial use. The mould protection (Microban®) is also missing here. However, private consumers benefit from a good brand product at an extremely favourable price. The Armaflex® ACE, with production facilities in Poland, is produced especially for the vehicle fitter, who appreciates the easy workability of Armaflex® insulation materials without having to dig unnecessarily deep into their pockets.

The Armaflex® ACE is not available in our online shop. We recommend the discount shop Van Damm.

K-Flex ST - our tip

An alternative to Armaflex® is definitely the K-Flex from the manufacturer L'Isolante. With similar insulation values to the Armaflex® AF and XG, the rubber sheet is just as suitable as the competition. According to the manufacturer, the thermal conductivity is even better with λ 0º = 0.031. Mould-preventing protection is also integrated here, which is certainly a nice addition for the "living space" application. Only the well-known brand name is missing.

We are the only online shop in Germany that can offer the large K-Flex product range: So you can choose the rubber panel in any insulation thickness from 6mm to 32mm.
You can also find our own tape, cleaners and the right adhesive for the K-Flex in our online shop.

In our opinion, the K-Flex ST is a real alternative and even outperforms the Armaflex® AF.  

K-Flex lying on carton

K-Flex rubber sheet, image: IK Insulation Group

K-Flex SC

Another alternative from L'Isolante is K-Flex SC. With its values, it is equivalent to Armaflex® XG and can be used without hesitation for all motorhome extensions.

Kaiflex KK

Kaimann produces another rubber sheet called Kaiflex KK: its values do not quite match those of the competition - but it is superior to Armaflex® ACE and is therefore also approved for commercial use. Due to its low smoke emission, Kaiflex KK reliably contributes to safety in case of fire.


Kaimann Logo;  Bild: Kaimann

Comparison table: Product data of all rubber panels in our online shop

Note: For a simplified overview, we have compared all rubber sheets with an insulation thickness of 19mm. The product properties of the insulation mats >25mm may deviate minimally.

Armaflex® AF Armaflex® XG Armaflex® ACE* K-Flex ST K-Flex SC Kaiflex KK
Area of application -50°C to +110°C (+85°C for full-surface bonding to the object) -50°C to +110°C (+85°C for full-surface bonding to the object) -50 °C to +105 °C -165°C to + 85°C -50°C to +85°C -50 °C to +105 °C
Thermal conductivity λ 0º = 0,033 λ 0º = 0,033 λ 0º = 0,036 λ 0º = 0,031 λ 0º = 0,035 λ 0º = 0,033
Water vapour diffusion resistance µ = 10.000 µ = 10.000 µ = 7.000 µ = >10.000 µ = 10.000 µ = 7.000
Fire behaviour

Euroclass B-s3, d0

flame resistant

Euroclass B-s3, d0

flame resistant

Euroclass D-s3, d0

 normally flammable*

Euroclass B-s3, d0

flame resistant

Euroclass B-s3, d0

flame resistant

Euroclass C-s3, d0

flame resistant

Reduction of sound transmission up to 30 dB(A) up to 30 dB(A) Not specified Not specified Not specified Not specified
Anti-microbial behaviour


No No Yes No No

* Not approved for commercial purposes