Are You Geared For Brass Monkey Weather?
Martin Cummins on working in winter
WINTER presents new challenges for floor fitters. Cold weather, reduced daylight hours, transport difficulties and poor site conditions all impact on subfloor preparation and associated products.
The main problems are generally due to products being unable to cure and/or dry out as efficiently because of the cold and damp. This can pose major problems with subfloor preparation, but can also hugely impact on the installation of decorative floorcoverings.
The following pointers are based on the assumption that subfloor preparation has been done correctly.
There are two main components when installing floorcoverings, namely the adhesive and the
• The use of solvent-free adhesives and primers during subfloor preparation in colder weather poses issues. These products generally work by some or all the moisture evaporating to leave a tacky film to which the floorcovering is applied and compressed to create the bond.
Cold and or damp conditions greatly prolong the time for this to occur and often cause a large reduction in the tackiness, making it difficult for the floorcovering to correctly bond. This is most visibly seen with tackifiers and pressure sensitive adhesives where the polymer level of tack is highly dependent on temperature.
Also, very low temperatures, below 5degC, especially if adhesives are left overnight to dry, may cause a film of condensation creating a barrier to adhesion, albeit microns deep, for the floorcovering.
Some of the most loved products are solvent-based, or at least low level solvent, such as contact adhesives for covings and rubber based adhesives for carpets. But these are products to help you get over the bad conditions which you shouldn’t be installing in the first place!! The likes of PU or 2 part epoxy adhesive suffer from cold temperatures delaying their cure.
High humidity may assist some single part PU adhesives which are moisture curing, so may actually reduce any working time.
The types of floorcoverings flooring contractors install include textiles, vinyl (PVC) sheet or tiles, rubber, linoleum and timber.
Let’s look at each individually and consider the impact of poor winter sites. This will hopefully prove that getting conditions right is a primar y impor tance, not just something that would be ‘nice if we could get it’.
• Textiles: The main problem is that under damp conditions these can often ‘relax’ because the fibres are in a dampened state. If fitted in this state the carpet will look fine, but as the building dries out and warms up the fibres ‘tighten’ up. This causes the carpet to shrinking back…who hasn’t seen gaps at seams on the like of fibre bonded carpet?
However, textile manufacturers apply backings and do everything they can to stabilise the product and adhesive manufacturers tr y to manufacture products to give extremely strong bonds to resist this movement. But this isn’t a cop out for the flooring contractor who ought to be trying to get conditions right to minimise problems.
• Vinyl: The main problems are often more pronounced during installation. In cold temperatures the flexibility of vinyl sheet will be greatly reduced. Getting the vinyl to lay flat directly off a roll is in itself a challenge. It can split if you try to cut it in the stiffened state.
Also, trying to bend vinyl for coving and the like is extremely difficult as it will try to return to its original state.
Furthermore, vinyl successfully laid in cold conditions will also come under significant strain as the site warms up. The strength of an LVT as it warms up can be significant and cause lipping at joints.
• Rubber: The issues here are similar to vinyl, but can be even more so with rubber thicker than 4mm extremely difficult to ‘flatten’ in the cold.
• Linoleum: Off a roll this is difficult to get flat and can split on cutting and bending. Backings are generally hessian/jute which can relax in the damp and tense up as it dries out, behaving similarly to textiles.
The above three products all have excellent guidance installation manuals from manufacturers as well as the BS 8203 code of practice, all stating the need for a minimum temperature usually 15degC. It is there for
• Finally, timber: We all know what happens to damp timber when it dries out. If not treated for external use or if the wrong type or non-seasoned timber is used, it warps, splits and shrinks.
Manufacturers try and minimise potential problems by creating more dimensionally stable engineered products and flexible adhesives. But there is no excuse for us not following guidance notes and standards.
Do make a song and dance about poor conditions and pressure main contractors to rectify them. After all, we are a professional trade and want to remain that way.
Martin Cummins is Ultra Floor technical sales manager
T: 01827 871871
This article has been reproduced from the Contract Flooring Journal website. You can find them at www.contractflooringjournal.co.uk.