Factors to Consider and What to Expect During Sanding and Coating

Factors to consider and what to expect during sanding Australasian timber flooring association and coating E [email protected] Information Sheet #84 July 2018 W www.atfa.com.au

Introduction This information sheet outlines what owners should expect and factors to consider throughout the sanding and coating process for an onsite sanded and finished timber floor. This can include solid T&G flooring, parquetry and other flooring types that have been sanded and finished onsite or recoated.

When should the finishing of the floor happen? There are a range of different scenarios for when a timber floor will require the sanding and finishing process, with all projects having varying time pressures and site conditions to contend with, but it is generally accepted within the industry that the finishing of the timber floor should be completed as late in the build or project as possible. The main purpose of this is to minimise any potential damage that could happen to the completed floor. Rectification of scratches, dents, contaminants and water or paint stains can become very costly and can compromise the appearance of the finished floor. Thought should extend to external factors such as driveways being completed prior, to minimise dirt, dust and stones being brought inside and simple things such as lights and power availability can easily be overlooked when scheduling for the floor to be finished.

Providing Power A finished 180mm wide spotted gum floor The sander will use a variety of equipment to finish the floor, with the majority of the tools requiring electricity. The big machine (belt or drum sander) needs a lot of power to start and run, and sanders will often work in teams, so it would not be unusual for 3 to 4 machines such as orbital sanders, edgers and vacuum cleaners plus the big machine to all be running at once. This can put a heavy strain on the electrical circuits, so it is important to make sure there is sufficient allowance on your circuit board to cope with the heavy loads. If power is not available, then generators can be hired to provide the electricity, but this should be discussed with the sander prior to the commencement of the job. Many sanding jobs have been delayed because the power requirements of their equipment have been underestimated. Making sanders run long leads off builder’s power on construction sites is not ideal, as this can cause power drops in the machines, resulting in irregular revolutions of the belts, which can cause unpredictable sanding marks in the floor and damage the machines. Having access to sufficient lighting is also important for a sander so that they can see what they are doing and can spot potential issues and rectify them as they work. Adequate natural and artificial lighting plus a reliable power source will give the sander the best opportunity of achieving a smooth and even finish.

It would be reasonable for a sander to expect to turn up to a relatively clean site with good access. There is heavy equipment to bring in and potentially large areas of flooring to prepare. Requesting that painters tape the floor in front of skirting boards (and remove their tape once painting is complete) and giving the space a general sweep and tidy up before the sander arrives will go a long way to creating a positive environment for the sander to do their best work. Protecting stair treads and risers also helps, as these can be very time- consuming areas to prepare.

The sander should inspect the floor prior to commencing the work to ensure that there are no moisture issues or potential contaminants and to work out the appropriate paper grits and method of floor sanding that will best suit the timber species, floor type and current condition of the floor.

When sanding works are being carried out in an existing home, it is recommended that unsealed foods are removed from the timber flooring areas, as some coating products (specifically solvent based coatings) can leech into foods, making them unfit for consump- tion. Similarly, with fish in aquariums, these should be Sanding should not begin without this board being replaced, moved from the dwelling to avoid the water absorbing as it is sitting too low and can’t be sanded flat. coating vapours.

For owners who are unfamiliar with the sanding process, it would be expected that the sander explains the steps involved, discusses the finishing options and addresses any concerns that the owner might have prior to commencement on site.

Common questions asked by owners

Will there be much dust?

Most of the powered equipment used will be attached to a dust bag or connected to a vacuum, which collects the majority of the dust. This reduces the amount of dust in the air and on the floor, allows the sanding equipment to work more effectively and reduces any health risk to the sander. Vacuuming before coats further removes dust from the floor, which helps minimise dust contamination in the coating. Having said this, the process is by no means dust free and a thin layer of dust can be expected to fall on benches, sills, curtains, nearby carpet and anything else exposed to the general timber flooring area.

In a new home, this excess dust is easily cleaned up once the floor is ready to walk on, but in an existing home it is good practise to remove or cover curtains, remove items from benches, tape along kitchen cupboard openings and hang plastic to protect cupboard contents and other rooms not being sanded. Although every effort will be made by the sander to reduce dust, they cannot be expected to clean up all the dust that settles around the home.

Should the internal doors be taken off?

Most experienced sanders are used to working around internal doors and they would generally remain in place during the sanding works with it expected that the sander would undertake as much of the work as possible with the doors closed. Having to refit the doors on a finished floor introduces the potential risk of scratching or damaging the final coat. If the sander notices a potential issue with a door they may ask that it is removed, beyond this, internal doors can usually be left on for the duration of the job.

2 © Australasian Timber Flooring Association Ltd. 2018 Can I have my floor sanded and coated in stages?

For best results, all timber flooring in the same project should be prepared, sanded and coated as one job. Coatings and timber are always reacting to the surrounding environment including UV light from the sun, which can change the colour of the floor over time. By finishing different parts of a floor with time gaps of weeks or months, the potential exists for each finished area to look different to other parts of the floor that were completed earlier.

When staging of the project is inevitable, a clear break in the floor is beneficial like a step down or staircase or a visual break such as a wall or separated room to help conceal any colour differences over time. When this is not possible try to finish along a board join as often this will minimise any difference.

How long will the job take?

There will be many factors that affect this such as the size of the job, the type of finish being applied (E.g. staining or clear coating), the type of flooring (E.g. old or new, clean or full of feature), how many people are in the sanding team, the layout of the floor and so on. The temperature and relative humidity can also affect how long it takes for coats to dry and can sometimes dictate what parts of the day the coats can be applied.

Once the flooring contractor has seen the floor and checked the forecasted weather conditions, it would be reasonable to expect a fairly accurate estimated date of completion prior to the commencement of the work. It is good practise for a sander to delay applying the final coat in windy conditions or on days of extreme temperatures.

As a rough guide, an experienced 2 person sanding team under normal conditions should be able to finish a 100m2 of new flooring with 3 coats of clear finish in approximately 3 – 5 days.

Can I stay at the house whilst the work is being done?

Generally, once the sanding work commences, the floor and any adjoining areas of the building will become completely inaccessible until the final coat has dried and is ready to walk on. Whilst some are low in VOCs (resulting in odour until cured) and give off very little smell e.g. water-based coatings, it is not recommended that people sleep in a dwelling that has a wet coat drying.

People entering the space can also introduce contaminants or might step in the coating, which can create more work for the flooring contractor and can compromise the quality and durability of the finished floor. Therefore, alternative accommodation for the duration of the job plus drying time after the final coat is recommended.

Will there be any damage to the skirting boards, kitchen or walls?

It is common practise for sanders to be working right up to finished kitchens and painted skirting boards so it would be reasonable to expect that some minor damage can occur to these areas. Occasionally the edging machine might mark a skirt or a wall may get scuffed, and this would be considered a normal part of the job, but anything that requires more than a simple paint touch up would be unacceptable and should be brought to the attention of the flooring contractor.

It is important to allow sufficient time for skirting board paint to dry and cure before sanding and coating the floor, as new paint coming into close contact with the floor coating can chemically react or if the paint is still soft then the sanding equipment might scratch the paint off more easily. It’s helpful to let the sander know when and with what type of paint the Caulking at the perimeter can provide a seamless skirting boards have been finished with. finish.

© Australasian Timber Flooring Association Ltd. 2018 3 If the floor is being stained or tinted with a colour, then this process can result in some colour ending up on the skirting boards and they may require repainting on completion of the floor. If skirt damage is expected because of the type of finish being applied to the floor then this needs to be planned for and explained by the flooring contractor. Sometimes it can be more beneficial to leave the skirting boards off and install them once the floor has been finished to avoid any skirting board damage. Masking the skirtings prior to the application of stain to the floor helps minimise marking of the skirting boards.

Should I caulk around the floor’s perimeter?

This is a personal decision that is often not an option when your floor is being completed as part of a building project. Most floors are not completely flat once installed. If the skirting boards are fitted prior to any sanding of the floor, then there may be slight and varying shadows underneath the skirting boards.

Similarly, when cabinetry is installed over the unfinished floor, the same result can ensue. As the flooring contractor cannot sand underneath these areas, an uneven finished edge can sometimes remain around the perimeter of the floor upon completion. The most common way to conceal this is to apply a bead of silicon or flexible caulking compound to the perimeter, which provides a seamless finish. Ideally silicone should not be used as this can contaminate the coating and has the potential to cause coating rejection issues in the future. However flexible acrylic or polyurethane caulks will pose less of a contamination risk to the coatings if future sanding work is ever required with acrylic caulks most commonly used.

Caulking is a separate professional trade from sanding and finishing, so the discussion is worth having with your sander about how the perimeter will be finished. If ‘caulking’ is undesirable to you, the flooring contractor may be able to provide an additional quote to come to the site prior to skirts and cabinetry being installed and sand these areas flat, known as a pre-cabinetry and perimeter sand so that these items will sit more evenly on the floor. This should eliminate the need for ‘caulking’ around skirting boards and will provide a finish with sharper lines if this is the desired look. It would be expected that the contractor fitting the skirtings would scribe them to the floor to ensure the most pleasing result.

Whichever finishing method you prefer, it is wise to discuss this with your flooring contractor or project manager in the early stages of planning to avoid any surprises or hidden costs.

When can I walk on the finished floor and move my furniture back in?

Different coating systems have varying drying times and it can take anywhere between 24 hours and 5 days to be able to safely walk on the floor after the application of the final coat. If urgent access is required, your flooring contractor and the coating’s manufacturing guidelines will help you determine the minimum time required before the floor can be walked on. Accessing the floor in this early stage of curing is risky, so only dry, clean socks are recommended for walking on the floor. Shoes and bare feet should be avoided and the floor should not be walked on until the flooring contractor indicates that it is acceptable to do so.

It’s important to understand that the floor coating can take weeks to fully cure and that during the early days after completion, the coating may be soft and scratch easily, so care must be taken when moving furniture back into the space. Most coating instructions recommend a minimum of 48 hours before furniture can be brought in and up to 4 weeks before laying down carpets or rugs and covering areas of the floor. Waiting as long as possible for rugs to go down will help minimise the colour change that can occur at the edges of rugs over time.

On completion of any site sanded and coated timber floor it’s helpful to check with your flooring contractor and the A completed 85mm messmate floor ready to use

4 © Australasian Timber Flooring Association Ltd. 2018 coating manufacturer’s product information to confirm the following 5 important points:

When is it safe to walk on the floor?

• When is it safe to move furniture on to the floor? • When can I cover areas of the floor with carpets or rugs? • When can I start safely cleaning the floor with moisture? • What should I clean my floor with?

Most sanders become very familiar with the coating products they use and should be proactive in providing you with the answers to the above questions and suitable cleaning and maintenance care instructions.

Communicate and work together

Open communication and a well-planned schedule are the keys to success. The sanding and coating stage is an exciting but potentially stressful time as the project draws to a close and the true beauty of the timber floor is revealed.

Work together, ask questions, be prepared and let the flooring contractor guide the process. With these few simple things in mind, you should be well on your way to receiving a beautiful timber floor.