Effective building insulation is crucial to help buildings stay cooler in the summer and warmer in the winter. With insulation that stands the test of time, buildings can maintain comfortable temperatures over longer periods without the need for recladding or reconstruction.
Although measuring durability is not always an exact science, insulation manufacturers can support customers and tenants by better communicating the durability of their products. We created the ROCKWOOL Durability Bulletin to clarify how levels of durability are defined and assessed, and to demonstrate how durable ROCKWOOL insulation is by drawing upon the results of recent testing.
Defining and assessing durability
Durability, in a building context, describes the capability of building products to meet key performance criteria over time, including thermal conductivity, reaction-to-fire classification and acoustics, to name a few. Products can be assessed before installation and after long periods of usage to determine the difference in performance over time. If the performance of the product has changed minimally, or not at all, then it may be deemed as durable.
It's important to note that, due to the lack of a universal standard, different bodies may approach durability assessments differently. Therefore, both manufacturers and building stakeholders may be wise to carefully consider the testing process or seek multiple points of evidence to support their durability claims.
Thinking long-term
Durable insulation eliminates the need to frequently remove and replace installed products which saves money, reduces hassle and gives added peace of mind to occupants and building owners. On top of this, if installed correctly, it can provide and maintain substantial fire protection, thermal insulation and acoustic performance for many years.
Without durable insulation, buildings are at a higher risk of having their performance drop off over time, which can result in increased costs to building owners and less satisfactory conditions for occupants. This points to a landscape in which building stakeholders might consider durability as a primary consideration when choosing insulation products, alongside their thermal or acoustic properties.
But, what overarching standards are there to consider?
The Declaration of Performance is a key part of the Construction Products Regulation. It provides information on the performance of a product. Each construction product covered by a European harmonised standard (hEN) or for which a European Technical Assessment has been issued needs this Declaration and must be CE marked.
Durability Characteristics as covered by section 4.2.7 of the relevant harmonised product standards (BS EN 13162:2012+A1:2015) state that the thermal resistance, thermal conductivity and reaction to fire performance of factory made mineral wool products ‘do not change with time’. As such, there is no requirement to make a declaration of aged performance for these parameters.
Laboratory research and real world design
Testing and projections are generally used to determine the durability of a product – but, what can really show value is testing from real-world products that have gone through decades of use. Lab research will go a long way to helping specifiers meet long term performance targets, but real-life product capability is what is truly experienced by building occupants.
There is now a range of field research and extensive test evidence from Eurima and the Danish Technological Institute (DTI) to suggest that ROCKWOOL stone wool insulation is durable and can retain its insulation capabilities for decades within external wall systems. Based on these results, ROCKWOOL is proven to last and retain its properties over long periods of time.
