How can I find out the age of an insulation material?
Age and year of production are important parameters when assessing the reuse potential of insulation materials. It is therefore advisable to determine this information as accurately as possible wherever you can.
When no production code or original technical data sheet is available, the age of the insulation can only be estimated indirectly. To do so, you can look at the year of construction or renovation of the building, the period in which the insulation was installed, and available plans, invoices, site reports or other project documentation.
If this information is also missing, a reliable year of production usually cannot be determined and the age is best considered unknown.
For PUR/PIR insulation boards, the year of production can often be derived directly from the production code. The way the date is written differs depending on the separator used.
A code with slashes usually uses the format DD/MM/YY. For example, 20/05/04 stands for 20 May 2004. A code with dots uses the format YY.MM.DD: 13.03.05 then corresponds to 5 March 2013.
For DOW XPS boards, the production date can be derived from the LOT code printed on the board. The first letter indicates the year of production and the second letter the month of production, with DOW using a sequential letter coding. For example, W stands for 2008 and X for 2009, while for the months A corresponds to January, B to February, and so on.
Following this system, the code LOT PF17080100 08:59 can be broken down as P – F – 17 – 08 – 01 – 00. Here, P refers to 2001, F to June and 17 to the day of production. The XPS board was therefore produced on 17 June 2001. The remaining digits are codes for, among other things, the company, the production site and factory-specific information.
Fire & acoustics
No additional fire tests or acoustic tests were carried out within the research project. However, given the relevance of both properties for insulation, Buildwise drew up the recommendations below.
No additional fire tests were carried out within this project.
The contribution of insulation materials to the fire safety of a building is determined by their reaction to fire and their role as an essential component within the complete build-up. Depending on building height, protection and facade concept, the Royal Decree on basic standards (KB Basisnormen) sets requirements for the reaction to fire of these components or provides specific standard solutions. The reaction to fire of the facade and the fire resistance of separating building elements are assessed at system level.
Mineral wool, such as glass wool and rock wool, generally has a very favourable reaction to fire (A1) and does not contribute to a fire. Within a construction, mineral wool can also limit temperature development, provided the material remains sufficiently dimensionally stable, clamped or fixed during the fire. To date, little intrinsic ageing of the reaction to fire is expected for mineral wool.
Plastic insulation materials such as EPS, XPS and PUR/PIR generally have a less favourable reaction to fire (D-F) and can therefore contribute to fire development. Fire performance may also depend on flame-retardant additives, facings and other product components. There is insufficient knowledge of how these evolve with ageing to make general statements for reuse. Their position and protection within the build-up are therefore important points of attention.
No additional acoustic tests were carried out within this project. The acoustic performance of a building is mainly determined by the complete build-up. Insulation materials can fulfil various functions in this, including as absorbent material in cavities and as a resilient layer for mechanical decoupling.
Mineral wool has good sound-absorbing properties thanks to its light, open, porous fibre structure. In the cavities of walls, floors and ceilings, it helps to dampen resonances and thus contributes to sound insulation. Airflow resistance, density, thickness and complete cavity filling are relevant parameters here. Insulation that has sagged or deformed can reduce acoustic performance because empty zones are created. In normal use, little intrinsic ageing of these absorbing properties is expected, as long as shape, position and connection are maintained.
Rigid closed-cell insulation boards such as EPS, XPS and PUR/PIR combine low weight with relatively high stiffness and a closed cell structure. As a result, they have little sound-absorbing effect and are generally not selected as absorbent cavity fill. Their stiffness can, however, influence the dynamic behaviour and resonance of the complete construction.
In floating floors, an insulation layer can also act as a resilient spring between the structural floor and the screed, thereby limiting the transmission of sound. The relevant parameter here is dynamic stiffness, which depends on material structure, density and thickness, among other things. A lower dynamic stiffness gives a softer spring and stronger mechanical decoupling. Long-term loading can change this property through creep and settlement. As the cases in this project focused mainly on recovering board materials originally used as thermal insulation, these products are not expected to have been specifically designed for this acoustic function or to have a declared performance for it. This application is therefore not considered further within the project.
Below you can find more information, per type of insulation material, on the presence of certain 'hazardous' substances.
For mineral wool, the possible age of the fibres is a point of attention. Mineral wool fibres that meet the conditions of Note Q of Annex VI to Regulation (EC) No 1272/2008 may be considered non-carcinogenic. In Belgium, the production year 1997 can be used as a practical indication, because from that period onwards mainly mineral wool with low biopersistence was placed on the market. If the product identity or compliance with Note Q cannot be sufficiently demonstrated, a cautious assessment is advisable.
For PUR/PIR insulation, historical blowing agents and flame retardants must be taken into account. Older boards in particular may contain F-gases that were used as blowing agents and have a Global Warming Potential (GWP). Boards from before 2004 generally still contain CFCs or HCFCs. Reuse is possible as long as the boards remain intact. Damage, cutting and shredding should therefore be avoided as much as possible to limit the release of residual gases. It is also recommended to identify these boards as ‘possibly containing F-gases’ when they are reused.
From 2004 onwards, these blowing agents were gradually phased out. PUR/PIR boards from 2005–2009 generally no longer contain F-gases, or in exceptional cases still contain HFCs. In addition, phosphorus- or halogen-containing flame retardants may also be present in PUR/PIR. Their presence and any consequences for reuse or processing must always be assessed in relation to the product, the substance and the applicable regulations.
For extruded polystyrene (XPS) insulation, hexabromocyclododecane (HBCDD) is a point of attention. HBCDD was used in the past as a flame retardant and is a persistent, bioaccumulative and toxic substance. Its manufacture, placing on the market and use have been phased out at European level, and HBCDD is listed in Annex I to Regulation (EU) 2019/1021 on persistent organic pollutants. In practice, the production year 2017 can be considered an important milestone, since from that period onwards XPS insulation placed on the European market in principle no longer contains HBCDD. If the presence of HBCDD cannot be ruled out on the basis of age and application, an additional assessment is advisable. An XRF measurement can be used as a screening method for the presence of brominated flame retardants.
In addition, for XPS insulation the blowing agent used must also be taken into account. Boards from before 2000 may contain CFCs or HCFCs with a high Global Warming Potential (GWP). Reuse is possible as long as the boards remain intact, but damage and shredding are best avoided, and the boards should preferably be labelled as ‘possibly containing F-gases’. XPS from 2001–2019 is generally blown with air, CO₂ and/or HFCs and can in principle be reused, although it remains advisable to limit damage. Boards from 2020 onwards mainly contain CO₂ and air, or in some cases HFCs with a GWP below 150, and from the point of view of the blowing agent generally do not pose an obstacle to reuse.
For expanded polystyrene (EPS) insulation, hexabromocyclododecane (HBCDD) is a point of attention. HBCDD was used in the past as a flame retardant and is a persistent, bioaccumulative and toxic substance. Its manufacture, placing on the market and use have been phased out at European level, and HBCDD is listed in Annex I to Regulation (EU) 2019/1021 on persistent organic pollutants. In practice, the production year 2017 can be considered an important milestone, since from that period onwards EPS insulation placed on the European market in principle no longer contains HBCDD. If the presence of HBCDD cannot be ruled out on the basis of age and application, an additional assessment is advisable. An XRF measurement can be used as a screening method for the presence of brominated flame retardants.