Floor Sanding And Polishing | How To Prepare & Terminology

Nothing quite compares to the organic quality and aesthetic appeal of hardwood timber floors. But like most things around the home, they need regular maintenance to keep them looking their best. In this article, we’ll cover what’s involved in polishing and sanding, how to prepare floors for either process, and whether it’s worth attempting to do it yourself!

Polishing vs. sanding

When it comes to the maintenance and restoration of hardwood floors, there are two main techniques — sanding and polishing. So when should you use each? It depends on your floor’s condition, and both methods serve different purposes. You can use these techniques together or separately, and there are pros and cons to both.

Polishing

Polishing is also referred to as “buffing”, and this technique creates a beautiful sheen, however, it’s not the most effective technique as it doesn’t get deep into the timber itself. Instead, it shines whatever wax, polish or varnish you’ve used to treat your floors. It is best done on older timber floors that are in a good condition, because they generally have a well-cured surface that responds well to buffing. Newer floors can be buffed after they’ve been treated, but it should be done just after a new treatment has been applied.

Sanding

Sanding is the better technique for restoring damaged floors. It strips the top layer of the timber, removes any unhealthy or dry wood to reveal the healthy timber underneath, and is then treated with a varnish or stain.

Both processes can be combined, but it depends on your specific floors. For example, if you sand your floors back to the grain and then apply a varnish or lacquer, buffing will create the best result. However, if you sand your floors back to the grain and then stain them, buffing probably won’t be necessary. This is because stains are absorbed by timber, so won’t create the right surface for buffing. That’s why outdoor flooring — like verandahs and decks — are rarely buffed.

In terms of scratches, it depends on the damage. If it’s just a shallow scratch on the surface, it’s probably only affecting the outer layer of wax, varnish or polish. In this instance, they will probably buff out. But if it’s a deeper scratch that penetrates the timber itself, you’ll need to sand back the timber itself.

Professional sanding

Sanding and polishing wooden floors can be time consuming and hard work, and whether you engage a professional or decide to do it yourself it all depends on the state of your floors. Professionals use different sanders according to the type of floors you have and the state they are in.

Types of sanders

Different sanders have their own peculiarities and will produce different results, and include:

Drum sander

This is the traditional sander used on floors and consists of a drum (cylindrical wheel) with sandpaper fixed to the outer surface of the cylinder. Sanding is controlled by the operator who brings the sanding drum into contact with the floor, but only when moving the sander forwards or backwards, as this will avoid drum marks. The machine is used throughout the main body of the floor to initially flatten it. It is then also used with finish sanding (see below). It is often referred to as the “big machine”. Common brands of machines include Hummel, Clark, and Galaxy.

Belt sander

This also contains a drum similar to the drum sander but has a small cylinder above which allows a sanding belt to be used. It performs the same task as the drum sander, and is used throughout the main body of the floor.

Edger

Due to the size of a drum or belt sander it is not possible to sand close up against walls, so a smaller hand-guided machine is typically used around the main perimeter of the floor. The edger has a rotating disc and is easy to manoeuvre. “Clocking” the edger is a technique of orientating the edger to the wall being sanded up to, to minimise the visual impact of the scratches left by this part of the sanding process.

Rotary machine

These machines have a rotating circular base plate and are used for hard plating and the final sanding of a floor. A finer grade of paper is fixed to the plate for the sanding operation. These machines are often referred to by the manufacturer’s name such as “Polyvac” or “Canterbury.”

With heavier machines such as the Canterbury, a less flexible or harder plate that supports the abrasive can be used to enable the floor to be hard plated. This type of machine is also used for “cutting back” between coats (when used with a more flexible base plate or pad), where the coating is mildly abraded to remove roughness and provide a mechanical key for the next coat. Often a fine sandpaper or mesh known as a “screenback” is used for this process. This type of machine may also be used in the application of some stains.

Trio

The Trio is a machine produced by Lagler and is a multi-head sanding machine that is ideally suited to hard plating. Whereas a rotary machine has a single rotating disc, the Trio has three smaller rotating discs. Multi-headed base plates are also now available for a variety of rotary machines including those mentioned above.

Random orbital sander

In sections of the floor that have been edged and areas that are difficult to access (for example, cupboards), a small hand-held random orbital sanding machine is often used to ensure these areas blend smoothly into the main body of the floor.

Corner sanding

In areas that are difficult to access and have been hand-scraped (for example, corners and sometimes along skirtings and joinery), a small handheld corner sander is often used to ensure these areas blend smoothly into the main body of the floor.

Preparation for professional sanding

If you prefer to call in a professional, make sure they have:

• Clear and safe access to the site. If you’re unable to meet the flooring specialist before they start the job, you’ll need to leave a key in a secure place. Some flooring specialists will be able to organise a lock box, allowing you to leave the key safely and provide access to your home.
• In addition to leaving the key in a safe place, you’ll also need to ensure easy access to your home to allow the flooring specialists to carry the heavy machinery required for sanding and polishing. Ideally, they should be able to park their vehicle directly outside your home.
• Adequate lighting and power. The flooring specialists you’ve hired will need lighting and power to sand and polish your flooring, so you’ll need to keep your home’s electricity on while they visit. If you’ve just purchased or sold the property, it’s important you still have electricity available in your name, as otherwise the job can’t be completed.
• Access to water. Water is used as part of the floor sanding and polishing process, so there needs to be unobstructed access.

Types of professional sanding

Professionals may use a number of techniques to sand your floors, including:

Level or basic sanding

This is undertaken with coarser grades (or grit) of sandpaper with the purpose of “cutting” the boards flat by removing unevenness (or mismatch) between board edges, and any shape deformation (for example, cupping) in the boards.

Prior to the removal of cupping from a floor, it is important to assess the cause of the cupping, and if it is moisture related, the floor should not be sanded as crowning may occur later. The paper grade selected for the first cut will vary from one project to another, and each project should be assessed on its merits to determine the starting paper to be used.

Generally, three passes are made over a new floor involving a large drum or belt sander, with the initial passes over the main body of the floor at an angle to the boards and then in line with the boards. This equipment is unable to access areas close to walls, around doorways or in corners of rooms.

Edging is the process of using a smaller sanding machine to make the boards in these areas flat, and also to provide a smooth surface to the main body of the floor. In areas that are difficult to access, a hand scraper is used and often a smaller sanding machine is used in conjunction with hand sanding. A “pass” refers to sanding of the complete floor surface with a particular grade of sandpaper.

Finish sanding

This is the process of taking a floor that has been levelly sanded and bringing it further along the path to the coating stage. The purpose of this stage is to smooth off the coarser sanding marks left by the level or basic sand with finer grade/s of sandpaper. The aim is to reduce the depth of scratching and prepare the floor for the next stage of the process.

Hard plating

When finish sanding is done, the next step is “hard plating” the floor. Although this is not undertaken by all contractors, it should be seriously considered to produce the best possible result. Hard plating is the process of utilising a rotary machine with the sandpaper on an inflexible base plate, and it enables a flat floor surface to be achieved. If undertaken effectively, it will help eliminate minor sanding imperfections left from using the big machine and edger.

Orbital sanding

After hard plating, the perimeter of the floor is typically sanded with a random orbital sander. The importance of both hard plating and random orbital sanding cannot be overstated to obtain a flat floor surface with little or no variations in the appearance of the finished floor when the perimeter of the floor is compared to the body of the floor.

Polishing

The final stage is the polishing or buffing of the floor. This is usually carried out with the same rotary machine that was used for the hard plating, but with the sandpaper attached to a more flexible pad on the base of the machine.

This is the final process prior to coating the floor and is designed to produce a uniform scratch pattern across the entire surface. It’s also used as the last checking process prior to the application of the coating.

Each stage of the sanding process is designed to achieve a specific outcome, with the end result being a floor that is flat with a minimum amount of very fine sanding marks, and little visible difference between any areas of the floor.

DIY sanding

If you decide to DIY – it, it’s important you do your research. Assess your situation carefully and make sure you have the right equipment on hand before undertaking the task.

Preparation for DIY sanding

In terms of sanding floors yourself, you’ll need assemble some materials beforehand including:

• Floor edger for skirtings
• Small detail floor sander for corners
• Hammer
• Nails
• Vacuum cleaner
• Large empty bins
• Lots of large bin bags
• Dust masks
• Ear muffs
• Heavy-duty extension cord (at least 10 metres long)
• Sturdy shoes
• A support person – this isn’t a job to attempt solo!

In terms of the sander itself, you will need a Polivac. This is easier to control than a belt sander, and works with a back and forth sanding motion, so it’s lighter and slower for first-timers. If your floor is damaged or has a few layers of finish on it, you will need a belt or drum floor sander. This will require a bit more upper body strength!

Sandpaper

Both sanders require the correct sandpaper and your choice depends on the state of your wooden floors. Sandpaper grits start as coarse as 24 and then move up to 40, 80, 120 and then Polyvac 150 grit. If you’re not sure, a 60 grit sandpaper is a good place to start. If your floors are extra rough, you will need something coarser, so a 24 grit may work better. As the process continues, you will need to progress to a finer 120 sandpaper for the finishing touches.

The process

So you have your chosen sander in hand. What now? Both types of sanders are heavy, so you will need your support person to help you lift and kick when you are using it so that you have a firm hold.

1. You will see directional arrows on it, which will indicate how you should attach the sandpaper. Drum sanders have removable handles to make this easier. It needs to be secured well at all times so you can keep an eye on the dust bag, which needs to be disposed of when it’s full.
2. Tip the sander on its side so it is open at the front. For your first round of sanding, you will start at the lowest grit before moving towards a 120 grit for your final finish. Slide the sandpaper roll onto the drum. It’s worth mentioning that you will be changing your sandpaper frequently, so go slow and constantly check it rather than charging ahead!
3. Start in the centre of the room. The aim is to keep the sander moving constantly and evenly — no jerky movements! Go with the floor grain both up and down and move forward in even motions. When you are turning, remember that you need to pull the drum back up. If not, you risk scarring your floors.
4. After each stage, remove as much dust as possible which will not only help with the clean-up, but make it a more safer and comfortable environment to work in.
5. When you are sanding wooden floors and you’ve reached the edges, you will need to swap to the edging sander for the skirtings. To make the process as smooth as possible, ensure the Polivac and floor edger are sanding your floors to the same gradient to ensure a smooth, professional finish.
6. Finer edges should be sanded with a small detail sander or by hand with the appropriate sandpaper grit.
7. If coating and polishing is required after sanding, it’s vital you remove all dust from the area.

Polishing

There are several stages necessary in the floorboard polishing process and each one serves an important purpose. It is crucial that each stage is done with consideration for your precise requirements and the specific nature of your timber flooring, which is why it is always advisable to contact an expert. This is because the the slightest oversight can have dire consequences on the integrity and durability of your timber flooring.

If you do not have a great deal of experience working with timber floorboards, it can be challenging to accurately gauge the extent to which certain preparatory steps are necessary. As well as this, it is not always easy to select the correct stain for your timber and failing to do so can leave you with inadequately protected timber flooring and potentially compromised its aesthetic appeal.

Different floorboards also degrade at different rates, even within the same house. This is due to a range of factors, including foot traffic, floor plan, humidity and furniture placement.

Essentially, there are certain areas of every home in which your flooring will be subject to more wear and tear on a daily basis. With expert help, it will be easier to not only identify these areas, but also ensure that the correct steps are taken to address any damage and restore the flooring to its perfect condition. Typical steps in the polishing process are:

Preparing the floorboards

The first step to restoring your timber floorboards is to prepare. This stage might seem like a relatively straightforward one, however it is always useful to gain the insights of an expert. Professional floorboard experts are familiar with the needs of a wide range of timber flooring solutions and can very easily identify any areas of your floor that require special attention.
The preparation stage is quite consultative and it generally involves inspecting the floorboards and assessing their suitability for a variety of products, before working out what needs to be done to facilitate the restoration of the timber. This will usually entail removing any furniture or carpets from the floorboards so that the polishing process can be done evenly and unimpeded.

Sanding the floorboards

The next stage in the floorboard polishing process is to remove any imperfections from the surface of the timber. It is not uncommon for timber floorboards to be scratched over the years and these scratches can compromise the protective layers of the timber and harbour moisture, which might then promote wood rot.

To prevent this, it is necessary to sand the surface of the floorboard back and expose the uncompromised timber beneath. Not only will this address any surface scratches, it will also remove the old varnish or stain and create an even surface upon which new products can be applied. Sanding is an arduous process and requires an extensive knowledge of timber and the right tools. For this reason, floor sanding is best left to the experts.

Applying sealing and polishing products

Following the sanding process, your floor will be ready for its facelift. When it comes to this stage precision is key, which is why this process can also be challenging for those without a great deal of experience in working with timber. It is important that the correct sealant and polish are used at this point, because they will have a direct bearing on the appearance of your timber flooring and the extent to which it is protected. Speaking to an expert will help shed some light on exactly what is necessary and they will have all the knowledge necessary to ensure that you get the best outcome.

Preparing floors for sanding and/or polishing

In terms of preparing wooden floors for sanding and polishing, you should:

• Clear all furniture. All furniture such as sofas, dining sets, and wardrobes will need to be cleared from the room being polished. This includes the inside of any built-in cupboards, and anything else covering the floor (such as rugs).
• Check for staples, tacks and smooth edges. Flooring can contain staples and tacks, which need to be removed before sanding and polishing starts. If the timber flooring is underneath the carpet, you’ll also need to remove the carpet itself, including any smooth edges that are holding it in place. If you’re not sure how to remove the staples and tacks, your flooring professional can provide a quote.
• There should also be no protruding nails — they need to be embedded below the surface by at least four millimetres. Any nail holes should then be filled with putty. Finally, do a thorough check of the area and sweep, dust and vacuum so there is a completely clean and empty surface to begin the job.
• Remove or cover items underneath the house. If your house is a Queenslander, or another type of property with a space underneath, you’ll need to ensure that all items are removed or covered, as liquid can drip through and ruin items. The last thing you want is your car to be peppered with dark brown polish!
• Remove unsealed food. Polyurethane is used as part of the polishing process, which can cling to nearby food and spoil it. For this reason, you’ll need to remove all unsealed food from your pantry and other storage areas, to prevent them from being tainted.
• Leave kickboards off. If you’re sanding and polishing the floor for a brand new kitchen, leave the kickboard off until the job is done.
• Complete first coat of paint before starting. If the area is being painted, it is recommended you complete the first coat before starting the job (except for the final coating on skirting boards), and the second coat after.
• Vacuum and clean the floor. To prepare the floor for sanding and polishing, you’ll need to thoroughly vacuum and clean it. For expert guidance, check out our article on the 4 Secrets For Cleaning Timber Flooring.

After sanding and/or polishing

When timber floor sanding and polishing is completed:

• Avoid walking on the floor for at least 24 hours. This will prevent the floor from becoming damaged while it’s still setting.
• It takes seven days for the polyurethane to fully harden. You can put your furniture back in the room at least 72 hours after the final coat is applied. Avoid dragging furniture—lift and place where possible to avoid scratching or gouging the floor.
• To minimise scratches of your newly sanded and coated floor, attach protective pads or small pieces of felt to the feet of furniture and heavy objects. These can be purchased from hardware stores.
• Never wear stilettos on timber floors as the heel point leaves indentations in the floor.
• Move rugs after two weeks. If left for too long, rugs can leave a permanent mark on your timber floor, so move them to a different spot after two weeks.

FAQs

#1 How much sanding dust will there be?

All modern floor sanding equipment has dust collection capabilities, however there will always be some minimal dust when stripping back timber floors in preparation for sanding and polishing. However, floor-to-ceiling dust control barriers can also isolate rooms and minimise dust in other areas.

#2 How long will the sanding and polishing process take?

Every floor sanding and polishing job is different, so the time frame will depend on the size and complexity of the job. However, generally most floor polishing and sanding jobs will take between three to four days to complete.

#3 How much will the process cost?

Again, this depends on a variety of factors, including the choice of your timber floor finish, any wood floor repairs and the condition of the existing timber floor. The removal of existing floor coverings will also incur an extra cost. However, as a general rule, it is around $33 per square metre in Brisbane.

#4 Can I stay in the house while the floors are sanded?

In some cases yes. For example, if you are able to live in the area not being sanded and can tolerate the smell and noise of a floor renovation for a few days! However, many people plan ahead and organise their holidays around this time.

#5 When can the polished floors have furniture put back on them?

Furniture can be replaced after 72 hours, however, all furniture that comes into contact with timber floors needs to have felt pads added for protection. Floor rugs (particularly non-slip underlays) should not be placed back onto the timber floors for a few weeks. This will enable the floor finish to completely cure.

#6 Can stains be removed from timber floors?

Some stains can, but unfortunately in some cases, animal urine and water stains may not sand out of a timber floor.

#7 Can gaps between floorboards be filled?

Floor board gaps are required for expansion and contraction with seasonal temperature changes experienced throughout the year. For example, in Brisbane, floor board gaps will be more noticeable in our dry winters and will close again in our humid summers. It is not recommended that gaps are filled between wooden floors because expansion and natural shrinking in the timber will cause edge bonding once coated. Filling gaps may ultimately cause cracking in the filler or timber floor.

#8 Do contractors remove lino, carpet and other floor coverings?

They can, and many of them will also dispose of them for you, however, it will incur an additional fee.

#9 Do contractors carry out timber repairs?

Yes, most contractors will offer a range of timber floor repair services including sub-floor repairs and floorboard replacement.

#10 Should timber floors be sanded before or after installing a new kitchen?

Sanding and polishing wooden floors before a kitchen installation is advisable as a completely flat floor is preferred by kitchen installers. It also reduces the likelihood of floor sanding equipment marking cabinetry. Once the kitchen is installed, contractors will generally return to deal with any minor damage incurred during installation and then apply a final coat of timber floor polish.

#11 What are “chatter marks” and “ghosting”?

Chatter marks are fine corrugations left on the surface of a timber floor after sanding and are more noticeable in reflected light. They are not an ideal look aesthetically and generally occur from contractors using inferior sanding machines, including old “drum style” sanders.

Ghosting is a term given to specific “milky-white” marks that appear on floors over time. They are often in the shape of a footprint, however other patterns or smudge-type marks in various shapes are also common. The issue seems to be more prevalent where direct sunlight makes contact with the coating, for example, just inside doorways.

#12 How do I choose a gloss level?

The gloss level of your polished floor is all about personal preference and can impact both aesthetics and the amount of cleaning that will be required daily. The four main types of timber floor coatings are:

1. Matt (dead flat finish)
2. Low sheen
3. Semi-gloss (approximately 60 per cent of full gloss level)
4. Full gloss

References

• Lee Dashiell, 2018, Deck building guide: What you need to know before designing and contracting the ultimate deck, Domain
• 2021, F.A.Qs About Floor Sanding Brisbane, Budget Floor Sanding
• 2021, Polished Floors F.A.Q. Economy Floors Brisbane