Cold-applied roofing membrane adhesives aren’t new to the industry, but they have come a long way. One of the main benefits of cold adhesive products is that they do not require open flames to apply. Every roofing project comes with unique conditions; for some, those circumstances may prohibit a traditional heat application process.
Why use solvent-based membrane adhesives?
Low VOC content
Solvent-based membrane adhesives were one of the very first technology developments of cold-applied solutions. Once in place, the solvent in the adhesive evaporates, leaving the remaining material to bond with the modified bitumen surface of the membrane by means of a solvent weld. They are still quite common in the industry simply because solvent-based materials are economical compared to other technologies. Also, project specifications and requirements – such as those of California’s Quality Management District requiring a maximum VOC content of 250 g/L – can often present a limitation. Over the past decades, solvent-based adhesive manufacturers have changed their formulation in order to meet this VOC content requirement.
Faster curing time
Even when those solvent-based products meet this COV criterium, their use is often limited by longer curing times, which could allow movement in the assembly and emit solvent odours for days, which might also cause physical discomfort for the workers and occupants. By contrast, today’s cold-adhered polyether-based products are solvent free (100% solids), offer high-adhesion performance and low odour, and contain less than 35 g/L of VOC, making them ideal for numerous applications.
Adhesives with very high solids content have less odour and lower VOC content. High solids content adhesives such as COLPLY EF often have fast curing time compared to asphalt solvent-based materials, which also means that they reach their maximum performance more rapidly. The solids content is a good indicator when it comes to the impacts and curing performance of the adhesive to be specified.
Ideal for every environment
Polyether-based adhesives are moisture curing and allow for easy installation of SBS-modified bitumen membranes in difficult wet or cold environments. In addition, polyether-based adhesives are ideal products to avoid outgassing on damp surfaces.
COLPLY EF and COLPLY EF FLASHING are good examples of polyether-based interply adhesives for roof membranes. These products are ideal solutions when construction works have to be carried out in occupied buildings such as schools, hospitals, or food processing facilities where solvent vapours are not tolerated, or where a roofing system is being installed on a combustible surface. COLPLY EF can be installed directly on solvent-sensitive or heat-sensitive materials.
It’s quite clear that cold-applied roofing membranes have come a long way over the years and are a welcome solution to today’s stringent building requirements.