Why an alternative to construction foam?
Every year, over 200 million cans of assembly foam are sold in Europe. The functionality, ease of use and wide range of applications of PU foam are impressive. It has been on the market since the 1970s. Whether as rigid or flexible foam, it is used in the most diverse areas of our daily lives: furniture upholstery, car seats, cold insulation, insulation of electrical components and much more. But there are also downsides, so there is much to be said for alternatives.
Calls for ecological alternatives are becoming ever louder, particularly with regard to greater sustainability. Accordingly Project tenders This is also becoming increasingly important. In order to be shortlisted, suppliers must be equipped to install windows and offer alternatives.
What ecological alternatives are there? What advantages do they offer? What is still in favour of or against installation foam? We provide answers to all these questions and offer an objective overview of the pros and cons of installation foam and possible alternatives.
Health
PU stands for Polyurethanewhich forms the basis for assembly foam. Isocyanates (MDI) in turn form a raw material for PU foam. And it is precisely these isocyanates that can Allergies trigger and Irritating to eyes, skin and respiratory tract. Some isocyanates are also under the Suspected carcinogenic to be. The Hazard statement H351 stands for this.
During processing, emissions are produced that can damage the Indoor climate pollute. Only once the substances have reacted and there are no more monomers is it safe for humans and the environment. For this reason, there was even a self-service ban on the sale of PU foam cans in Germany until 2017.
Sustainability and the environment
If you value healthy and sustainable construction, it is certainly not wrong to look for ecological alternatives to construction foam, as artificial or toxic substances are often added. Fortunately, the harmful blowing agent HFC is now rarely used.
However, it should still be noted that PU installation foam made from Crude oil is produced. An incredible 70 litres of crude oil are needed to produce around one cubic metre of polyurethane. The production of the basic material requires a high energy consumption.
Legal requirements
Since 2005 there has been an updated DIN 18355. The new regulation is part of the "Vergabe- und Vertragsordnung für Bauleistungen" (VOB) in Germany. It states that connection joints should be completely filled with mineral wool instead of PU foam. The reason for this is the better adaptability to possible expansions of the materials to be joined.
An EU regulation that came into force in 2020 stipulates EU-wide mandatory training on the handling of products containing diisocyanates from August 2023 before. This information will be mandatory on packaging from 2022.
In contrast to insulating foams for refrigeration and household appliances, etc., which are often not flame-retardant, the in the construction sector PUR insulation foam flame-resistant be. The flame retardant previously used for this purpose in polystyrene insulation foam in conjunction with a synergist (dicumyl peroxide) is now used as a flame retardant. Hexabromocyclododecane (HBCD) was developed in accordance with the European Chemicals Regulation REACH banned from 21 August 2015. It has been replaced by alternative flame retardants such as pFR. This makes insulating foam normally to hardly flammable (class E according to DIN EN 13501-1 or building material class B2 according to DIN 4102).
Tenders
More and more project tenders are focussing on a Sustainable construction. This includes MA 34, the construction and building management department of the City of Vienna. There is currently a discussion here as to whether suppliers should always be given a Offer an alternative to synthetic PU foam must.
The trend in this direction is increasing. In the near future, ecological alternatives are likely to be an unavoidable requirement in general. The sooner providers start looking around, the better.
Mounting foam, its advantages and disadvantages
In 1937, polyurethanes began to be synthesised and further developed until polyester foam finally became established in the mid-1950s. Nowadays, it is hard to imagine the construction industry without PU foam. Our neighbours in Germany, for example, insulate around 80 percent of their windows with this installation foam. And for good reason. The advantages are particularly evident when it comes to window installation:
Compared to other insulation materials, PU foam has the Best thermal insulation. Due to its easy handling it can be processed quickly and adapts to the Expansion perfectly to its surroundings as it dries, allowing it to reach even hard-to-reach areas. Another plus point is its Strong adhesive strength. It creates a secure connection between windows, window frames and materials such as concrete, wood, metal and other plastics.
Let's take a closer look at PU foam:
Advantages of PU foam
- Easy handling and processing
- Also gets into places that are not easily accessible and seals them
- Excellent insulation values
- Good insulating properties, even for electrical components
- Low thermal conductivity (0.030 - 0.040 W/(mk))
- Hardens quickly
- Expands during curing and thus adapts ideally to its surroundings
- Low costs
Disadvantages of PU foam
- Harmful ingredients (isocyanates
- Contains some propellants such as HFCs, which are harmful to the ozone layer
- Production from crude oil
- High waste production (take time into account)
- Due to the high adhesive effect and the resulting material composites, it is often difficult to dispose of them by type and is only possible with a high chemical or mechanical effort
- UV radiation can cause fractures
- Permeable to air and gas
MDI stands for the chemical methylene diphenyl diisocyanate. Since 1 December 2010, PU foam with an MDI content of more than 1 percent must be labelled accordingly.
The chemical is dangerous in that it can irritate the mucous membranes, eyes and respiratory tract. Even if it no longer escapes after processing, someone has to work with the foam first.
Are there alternatives to PU foam?
Synthetic alternatives
The synthetic alternatives include those Plastics that are chemically produced become.
They usually consist of Crude oil, Bakelite or Silicon dioxidewhich is then processed further. This is precisely why they are often criticised. They are available as boards or as granulate for blow-in insulation.
- Expanded polystyreneEPS for short, better known as polystyrene, is one of the most commonly used synthetic insulation materials.
- Closed-cell round profiles made of polyethylene are also alternatives for sealing. They are characterised by their dimensional stability, are free of blowing agents and do not absorb water.
- There are also so-called Multifunctional sealing tapes. However, these often reach their limits, particularly due to the building tolerance and the permissible joint width and the subsequent "blower door measurement".
Ecological alternatives
If you take a look at ecological alternatives, the choice seems to have increased in recent years. There is a strong focus on the environment and sustainability. We have taken a closer look at the alternatives:
Ecological construction foam without isocyanates
There are now construction foams that do not contain isocyanates, either partially or completely. These are treated with a EC1-Plus seal labelled. However, you should bear in mind that this is an industry quality mark, which means that no more vapours are released after 30 days.
Cork filler
Solvent-free dispersion spray cork is primarily for Sound and thermal insulation a good alternative for connecting joints. In outdoor areas, an elastic sealant must also be applied to protect against the weather. The advantages of this alternative are that No chemical substances releasedshe is Environmentally friendly, Permanently stable and dense. However, the high costs, poor thermal conductivity (0.054 W/(mK)) and the sometimes long transport routes of the raw material are clear disadvantages.
Hemp
Although hemp is a sometimes controversial plant, it can be used very flexibly. Around 97 per cent of industrial hemp is further processed and for good reason: hemp is Tear-resistant, open to diffusion, Durable, Hardly flammable (fire protection class B1), Grows quicklyis No hazardous waste and has a Incredibly good heat and cold insulation. But hemp also has a catch: an incredibly high amount of energy is required to produce insulation material from hemp.
Flax
Good thermal conductivity (0.040 W/(mK)), renewable raw material, open to diffusion, Easy disposal and the Energy-saving production - If you think of ecological alternatives to construction foam, there is a lot to be said in favour of flax. Especially in the interior, flax is often used for Insulation However, it is not recommended for outdoor use. Furthermore, the significantly higher costs often speak against this alternative.
Chemical-free window installation: Joint tape made from virgin wool
If you want to go for pure nature, then our ISOLENA window filler certainly a good choice. The carded wool ribbon can be used to Insulating and filling cavities in window and door frames and Skylights can be used in the area of the flashing. Installation is extremely simple: the joint tape is worked in with a spatula. Thanks to its high filling volume, the wool fills every cavity and provides ideal insulation.
Let's look at the advantages and disadvantages in detail
- Time factor = 1:1, compared to conventional foams
- No drying time, no re-cutting and reworking
- Can be applied at any temperature and humidity
- Harmless to health
- High sound reduction index: 62 dB
- Better fire behaviour: D-s2,d0
- Excellent thermal conductivity: 0.033
- Easy disposal with the best eco-balance: fully compostable
- Advantage when reworking the trades in drywall construction, reveal tapes are not damaged, a clean connection is ensured
- Permanently elastic, ageing-resistant and UV-resistant
"A key advantage between the foam variant and tamping is that tamping cords (joint tape) are already available in a prefabricated form before installation. This means that a specific product can be ordered for a specific joint size and then installed in one or two layers depending on the joint width.
Another advantage of joint tape made from sheep's wool is that it absorbs moisture very slowly in liquid form due to its natural lanolin content and can therefore withstand the occasional driving rain - remember where sheep's wool comes from."
Helga Haslehner
Isolena consulting and sales
Summarises the main advantages of the joint tape
"Working with ISOLENA joint tape is a pleasure for several reasons.
Processing is child's play and completely harmless to health.
The technical values, such as sound values, thermal conductivity or fire behaviour are top and there is no waste.
We are therefore happy to recommend it to our customers."
Engineer Roland Dorn
Our partner from Dorn Fenster und Türen GmbH reports from the field
Conclusion
PU foam definitely has its advantages. However, if you want to focus more on sustainability when building, there are now some very good alternatives available that you may not have thought of at first. Ecological alternatives in particular can be the ideal choice for your building project. If you have any questions, please do not hesitate to contact us.
