Matthew explains why, when working in a conservatory, near bi-fold doors or in any area that’s subject to temperature fluctuations, always opt for a HT adhesive.
THE rise in popularity of the use of bi-fold doors and large format windows, as well as conservatories, orangeries and atriums, can result in floor coverings being subject to high levels of direct sunlight. This leads to an increase in the surface temperatures that the flooring applications are subject to, which is commonly referred to as high solar gain, and these applications require the use of a high temperature (HT) adhesive.
The name ‘high temperature adhesive’ can be misleading. It suggests that such products can only be used in environments subject to high temperatures, but that’s not the case. HT adhesives perform well at low or mid-temperatures too, but the key is that they offer high bond strength and exceptional shear resistance over wide temperature ranges – from as low as -20deg C, all the way up to +60deg C.
As with any adhesive, it’s important to work within a HT product’s open and waiting times, as well as being mindful to the times required before any foot traffic is applied. A five to 10 minute waiting time is common for a HT adhesive, along with an open time of 25 to 30 minutes, which allows for small adjustments if required.
Knowing how an acrylic-based product works, as well as understanding exactly how the bonding process takes place also helps. There’s a high volume of a liquid component in acrylic-based flooring adhesives, that liquid being water. Water is the medium that carries all the important bits that make the adhesive work.
However, while the adhesive retains water, it’s unable to gain its bond strength. When applying an acrylic-type product, there are generally two processes in which the adhesive will allow its moisture to escape and dry. The first is by evaporation, which in short is when moisture disappears into the air. The second is by absorption, meaning the product’s moisture can soak into the subfloor, which enables such products to have a high-grab quality.
It’s important to make your decision
on which adhesive to use, and how to use it, based on the chosen floorcovering as well as the environment it will be subject to.
High temperature adhesives are versatile products that can be used with floorcoverings such as 4mm rubber flooring, all PVC sheets, linoleums, as well as LVT planks or tiles.
In some cases, temperature variations can cause LVT planks and tiles to shrink or expand, which can result in gaps becoming apparent over time. In this situation, wet or semi-wet bonding is required to allow full transfer of adhesive to the backing of the floor covering and enable adhesive ribs to be compressed before the adhesive becomes too dry.
It’s also key to use the correct equipment to apply the adhesive, such as a clean roller ensuring air is not entrained or trapped under the flooring and repeating after 30-45 minutes to consolidate the bond. Other benefits to look for when choosing a HT adhesive include resistance to plasticiser migration. To enable vinyl flooring to be so flexible and versatile, chemicals called plasticisers are added.
Plasticiser migration occurs when these chemicals within the plastic or rubber migrate and are absorbed by surrounding materials. It can take time for plasticiser migration to occur, but pressure and heat can speed up this effect.
Many high temperature flooring adhesives now feature a solvent-free formulation and low VOC emissions, resulting in a low odour product that’s safer for the installer and better for the environment. Products with such environmentally friendly properties are usually marked with a EC1 Plus classification.
In summary, when working in a conservatory, near bi-fold doors or in any area that’s subject to temperature fluctuations, always opt for a HT adhesive. Consult the flooring manufacturer’s installation guide to ensure adhesive suitability, and if in doubt, contact the relevant technical team – we’re always happy to help.
07767 228869
matthew.gill@bostik.com
www.bostik.com
Matthew Gill is technical consultant, Bostik
