The disruption that renovating a floor causes means that this is a common and understandable question from both domestic and commercial customers alike. Having your floors restored brings disruption, can mean moving out and perhaps even loss of revenue. In addition, floor owners have other concerns that need to be understood and addressed.

The subject of health and safety is one that is never far from the minds of people and the headlines in news and social media. Whether that is talking of microplastics, ‘forever chemicals’ or added chemicals in highly processed foods there are always discussions and views being aired. Customers can easily look for information on products on the internet, which means they are informed about what may be used on their floors. The chemicals and solvents used in the flooring industry are under more scrutiny from both contractors and homeowners than ever before, even when it comes to products as innocuous as diluted floor cleaners.

In addition to this there are a growing number of both commercial and domestic contracts where specifiers are looking for compliance with Standards and Codes. Some, which you may have seen on datasheets, require products to meet limits regarding solvent content, like A+ Emissions (FR), EMICODE, DIBt & AgBB (DE) and Greenguard (US). Others like LEED, BREEAM, Living Building Challenge and GreenStar have both solvent restrictions and restrictions on the raw materials within the products together, in some cases, with other restrictions. There is also a growing movement requiring products to have an environmental product declaration (EPD) which details the environmental impact of a product or material throughout its lifecycle.

When it comes to your working methods and product choices, perhaps the main question to think about is what steps you take when quoting and working to mitigate the subsequent impact afterwards. You have a Duty of Care under the law to all people who are present on the site during or after any works carried out by you. That includes your offsider, other workers onsite and of course the customer.

You are required to protect you and your staff and advise others of the risks of solvent exposure, dust exposure, noise exposure, etc. Protection against solvents for workers has been discussed many times and there is a lot of information available, both through ATFA and on-line. The recent cases in relation to silica dust exposure should be a wake-up call, when hardwood dust is a known carcinogen. Manufacturers have dust control systems available that are rated for both M and H class requirements; an H class system will pick up 99.996% of particles 0.0003 mm in size. These can both help protect you, your staff and others on the site, and reduce the amount of residual dust left to clean up.

The continued availability of all types of products containing high levels of solvents clearly presents risks to both contractors and their customers, with many studies detailing the adverse effects from solvent exposure. It also affects the customer’s experience and costs in relation to the contract because of the pervading odours and the time before reoccupation.

Where better to look for information than within ATFA documentation. Information Sheet 91 looks in depth at the subject of outgassing, sometimes called offgassing. The document can be used to illustrate some key points:

• The escape / dispersion of volatile solvents and other solvent fractions occurs during the drying / curing phase. This can take days or in some cases many weeks.
• If you can still smell the solvents, then the process is still taking place, and sometimes that can be the case even without there being a noticeable odour.

What can affect the process?

• Site conditions – ventilation and temperature as you may expect. As we all know, if it is cold and / or there is poor ventilation any drying / curing process takes longer and vice versa.
• Absorbency of the substrate / number of coats – basically the more product present, the longer it will take for the solvents to disperse.
• Time between coats and the site conditions during coating. With ventilation between coats and coats applied at longer intervals then the solvent will disperse quicker as solvent isn’t ‘trapped’ and having to pass through subsequent coats.
• The product type – some products have lower VOC contents.

There is surprisingly little information on the datasheets of solvent based coatings about when a property can be reoccupied. Almost without exception they give advice for protection when using the products and send the reader to the Safety Datasheet, which gives further detailed information regarding this, but again nothing about reoccupation. Some documents advise 7 – 10 days or that it may take even longer, but there certainly is no widespread detailed advice available.

It has been clear since the initial introduction of waterborne finishes in 1980 that the best approach to reduce the exposure of both contractors and their customers is to use low VOC products, and this is clearly noted in ATFA Information Sheet 91.

Which brings us neatly back to the question – When can my customers move back in?

With regard to the finish / coating system, it is clear you should be advising customers to choose a system using waterborne finishes. The European directive of 2007, as adopted by ATFA, set an upper limit of 140 grams / Litre VOC content. These days many waterborne finishes are below 50 g / Lt, and the newest one component products for use on commercial floors are around 30 g / Lt, less than a quarter of the EU limit. Solvent finishes and stains contain many times this level of solvent with figures of between 300 and 800 g / Lt not being uncommon.

With a waterborne finish system, it is possible to advise clients that they could stay in areas of the house away from the newly coated floors and / or move back in within a couple of days, if larger areas are being coated. In commercial properties it is common for floors to be coated and the floor to be put into full commercial use 24 hours later, or sooner in some cases.

Even where there is a need to colour a floor you can now replace solvent based stains, which usually will have a solvent content of over 500 g/Lt, with 2 component oils that can be overcoated with a waterborne finish. With a VOC content around 25 g / Lt the solvent level in the 2K Oil system is lower than that in the finishes used for the final coats in the specification.

Years ago, it was argued that solvent based products were superior in performance to waterborne finish systems. That has not been a valid argument for many years with waterborne systems now being used on commercial floors ranging from restaurants, pubs and clubs to The Opera House and the National Portrait Gallery, shops, sports floors, houses and even heritage listed railway station waiting rooms. The health and safety implications for you, your staff and your customers together with the convenience of being able to move safely back into rooms with newly restored floors means that the use of waterborne finish systems is the clear and obvious choice when deciding what finish system to use on a project.