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Some of the most frequent questions we get asked are about how to sand wooden floors. We’ve definitely sanded more than our fair share of floors and floorboards and know just how daunting the task ahead can feel.
Sanding your floors and floorboards is a lot easier than you probably expect and it’s totally possible to achieve a professional result even as a DIYer! There are a couple of floor sanding questions that come up again and again, so we’ve put together this (very long) list of Q&As that will hopefully give you a good idea of what to expect if you’re considering doing the job yourself.
To make it easier for you to find the floor sanding advice you’re looking for, we’ve broken down the Q & A’s into 7 sections.
1. Before you start
2. Sanding Floors
3. Floor Finishing
5. Cost of Sanding Floors
7. Tips & Tricks
Before You Start
WHERE DO I BEGIN?
After completely emptying your room, remove any old floor coverings, nails and anything else that is attached to the floor and then give everything a good vacuum and clean. Basically, you want an empty and clean surface to start working from.
DOES THE ROOM HAVE TO BE COMPLETELY EMPTY?
Ideally – yes. The big drum sander that you’ll be using is really bulky and you really need space to move around the room easily. Having said that, when we sanded our dining room floor, we did leave our blue sofa and sideboard in the room because we just didn’t have anywhere else to put them.
We ended up completely sanding one-half of the room and then moved the sofa over to sand the other half of the room. Of course, it wasn’t ideal, but it wasn’t awful, either.
MY FLOOR IS IN A POOR CONDITION. WILL IT STILL LOOK OKAY WHEN IT’S SANDED AND FINISHED?
Don’t get me wrong, if all of your floorboards are rotten and you have big holes everywhere, even the best sanding job isn’t going to make it look good.
Having said that, our kitchen floor looked absolutely awful, but after replacing a few of the rotten floorboards and giving everything a sand, it’s actually not turned out too bad (although I should point out that this was always only meant as a temporary solution and really isn’t the quality of finish you should be aiming for).
WHAT TOOLS WILL I NEED TO SAND MY FLOORS?
Basically, you will need a drum sander and an edging sander. A good hire shop will give you what you need and show you how to use the machines. No need to worry though as the tools are really simple to use!
ARE THERE ANY OTHER TOOLS OR EQUIPMENT THAT I’LL NEED?
WHAT PROTECTIVE EQUIPMENT WILL I NEED?
It’s always important to be safe so you’ll definitely need some high-quality dust masks (we’d recommend FFP2), some ear protection (propper ear muffs are obviously best, but some earplugs will work, too) and sensible shoes.
IS THERE ANYTHING ELSE I HAVE TO PREPARE?
Make sure your floor is completely flat and nail free. Every guide states that you should punch every nail of your floorboards into the wood so that it’s about 2mm under the surface.
DO I REALLY HAVE TO PUNCH DOWN EVERY NAIL BEFORE SANDING?
In our opinion – no. Of course, you can’t have any nails protruding out of the surface, but we didn’t find it necessary to punch down the nails at all.I should point out that this is NOT recommended and you will definitely have to be careful with your sander, as it can catch on a nail and rip your sandpaper or worse, damage the machine. The floor sanding company that tackled our living room floor also didn’t bother with this step. Definitely, something to do at your own risk!
Yes! Sanding your floors is easier than you probably think but it is physically hard work! Do your research and be well prepared.
HOW DO I ACTUALLY SAND A FLOOR?
You will have to sand around the edges of the room with the edging sander and sand the rest of the floor with the large drum sander.
If you have really, really uneven floorboards, you should start by sanding (with the large drum sander) diagonally to the floorboards to even the floor out and then move on to sanding in the direction of the boards. As a general rule, you always sand with the grain of the wood!
You will have to sand around the edges of the room with the edging sander and sand the rest of the floor with the large drum sander. If you have really, really uneven floorboards, you could start by sanding (with the large drum sander) diagonally to the floorboards to even things out and then move on to sanding in the direction of the boards. As a general rule, you always sand with the grain of the wood.
WHAT KIND OF SANDPAPER SHOULD I USE?
The type of grit will ultimately depend on your floor. What condition is it in? Are the floorboards wavy and uneven? Has it been painted or is covered in carpet glue?
We used 16 grit, 24 grit, 40 grit, 60 grit, 80 grit and 120 grit. Start sanding the floor with some really coarse sandpaper to remove old layers of varnish and even your floor out. Only when your floors are free of the old layers of varnish, stain and grime, can move on the less coarse paper.
If your floorboards are ‘just’ dirty or have a thin coat of paint on them, starting to sand with 24 grit sandpaper should be sufficient. If your floorboards are really uneven or painted in a thick coat of paint, you will probably be best starting to sand your floors with 16 grit paper.
IF I’VE REMOVED ALL OF THE DIRT AND GRIME WITH THE COARSE PAPER, WHY DO I HAVE TO BOTHER SANDING IT AGAIN WITH FINER PAPER?
The really coarse paper will really eat into the floorboards and leave a very rough surface. With each sand with finer paper, you are removing and smoothing out the roughness of the wood. Don’t skip the really fine paper either. It really does make your floor much smoother, more professional and easier to maintain.
HOW MUCH SANDPAPER WILL I NEED TO SAND A FLOOR?
Switch your sandpaper regularly – it’s definitely something we learned the hard way. The more frequently you switch the paper, the faster you’ll be able to sand the floors. Don’t underestimate the amount of paper you will need, either.
When hiring the machine you buy the paper, too, but usually, you can return any surplus. You don’t want to run out of paper, especially if you’re working at the weekend and can’t get hold of more! For the large drum sander, we used about 12 sheets of 24 grit, 8 sheets of 40 grit paper, 8 sheets of 80 grit paper and 5 sheets of 120 grit paper. For the edging sander, we used about the same amount of each grit again.
IS SANDING FLOORS BY HAND POSSIBLE? CAN I USE A HAND SANDER TO SAND FLOORBOARDS?
No. Believe me, I tried. It would also end up being a false economy, as even if you don’t count the impossible amount of time it would take to do, you would probably also end up going through such a ridiculous amount of sandpaper that it may even end up costing you more than to hire a machine!
You will probably use a detail sander to finish off the corners of your room, so if you are tempted to see if sanding floors by hand is possible, give it a try in a corner that you’ll be using a detail sander for anyway. You’ll see just how long it takes to sand a small corner and can then work out how long it would take to sand a full room!
WHAT TYPE OF SANDER IS BEST FOR FLOORS AND WHAT’S THE BEST FLOOR SANDING MACHINE?
The quality of machines does vary a lot and you’ll generally find that the machines you hire at a DIY store aren’t as good as the ones the professionals use. It’s definitely worth visiting either a dedicated floor sanding/supply shop or a hire shop rather than a general DIY store as they will be able to give you better advice on what machines will work best for your floors.
If you can get hold of one, we would always recommend using a Lägler ELF 200 as it’s by far the best machine for sanding floors and is really easy to use. As a DIYer though, it’s unlikely that you’ll be sanding hundreds of square metres so don’t worry too much about using other machines as they will all do the job.
WHAT IS EASIEST WAY TO SAND A FLOOR?
Use the right tools, use the right grit sandpaper and change it often. Take your time and make sure that the drum of the sander never stays on the spot to avoid sanding grooves into your floor. It’s physically hard work but not difficult to do.
HOW DO I SAND PAINTED FLOORS?
It doesn’t matter if your floors have been painted, varnished or are just covered in a century worth of dirt and grime. The process is always the same – empty the room, make sure your floorboards aren’t damaged and that the floor is safe and secure, sand the main surface of the room with the drum sander, use an edging sander for the outer edges of your room, clean and varnish, oil or paint when you’ve finished.
HOW DO YOU CLEAN BETWEEN SANDING YOUR FLOORS?
The best way to remove sawdust after sanding wood floors is with a good vacuum cleaner. The amount of sawdust you create is staggering and although a good drum sander will collect most of it, you’ll inevitably find that lots of sawdust will remain on the floor (and everywhere else in your home!).
We’d recommend investing in a vacuum cleaner that’s hard-wearing like the Kärcher WD3 that we have and love – as it’s pretty much indestructible, very affordable and you can use it with or without vacuum bags to save money.
After sanding and vacuuming for the last time before sealing your floor with varnish or oil, you can also wipe the floor with white spirit (it’s called mineral spirits if you’re in the US) to remove any fine sawdust. This is optional (we didn’t bother on our floors but it’s something we do when sanding and painting furniture) but it will leave your floors perfectly clean for your chosen finish.
Floor Finishing – Varnishing, Staining & Oiling
WHAT KIND OF FLOOR FINISH SHOULD I CHOOSE?
We’ve opted for both varnish and oil in the past and really liked both. A lot will depend on the product you use though as some varnishes can make the floor look plastic-y and some oils (and varnishes) can change the colour of your floors significantly.
When it comes to both oils and varnishes there’s an almost endless choice of products to choose from. We highly recommend using Granwax Aquathane water-based varnish as it’s extremely easy to work with, has only a faint odour, dried really fast, and most importantly, is extremely hard wearing! It only took a couple of hours to be able to walk over the surface again after applying the varnish which made it ideal, especially for areas like our hallway and kitchen. Another reason why we highly recommend this varnish is because it didn’t make our floorboards yellow and had a really natural non-plasticy feel.
Another option would be to oil your floors which is what we did in our second home. Oil definitely has a more natural finish than varnish but we did find day-to-day maintenance a tiny bit more involved. Basically, you can’t let the floor get wet so any spills and drops of water have to be wiped up immediately or they will stain the floor. Other than that, we loved the finish and oiling your floor is a really easy thing to do, too!
HOW DO I VARNISH A FLOOR?
This couldn’t be easier to do. Start by making sure you’ve removed all dirt and dust from sanding before varnishing. We only used a brush (this is the one that we used), but you could use a roller just as well. Let each coat of varnish dry completely before applying another.
We’d recommend 3 coats of varnish in low traffic areas and 4 in high traffic areas like your hallways. Always read the manufacturer’s instructions though, as the specifics can vary depending on the type of varnish you are using!
When applying the varnish, always make sure that you apply your brush strokes in the direction of the wood grain. That’s pretty much it. We found it easiest to work our way across the varnishing a few floorboards at a time.
HOW DO I OIL A FLOOR?
There’s almost no difference to varnishing it. Again, make sure your floor is clean and apply a coat of varnish with a rag or, as we did, a special oiling pad on a poll. When you’ve oiled the floor go over the whole surface with a clean rag to take up any excess oil.
Let the first coat dry before applying a second and third coat (letting each coat dry in between).
Exactly how you oil your floor will depend on the oil you use, so always read the manufacturer’s instructions!
WHAT IF I WANT TO COLOUR MY FLOOR?
We’d recommend using a stain and then a clear varnish on top. We’ve seen a few floors where a coloured varnish has been used which over time inevitably wears away and gets the odd chip and scratch. As the colour chips away, any marks are then really visible. If you stain and then varnish the floor, for the most part only the varnish will wear away leaving any chips less visible.
WHAT KIND OF GLOSS LEVEL SHOULD I CHOOSE?
As with all decorative decisions, the choice is yours. We chose to finish the floor with a clear satin varnish. We wouldn’t recommend using a matt varnish as the floor can quickly look dull on the other hand, a high-gloss varnish will show up any imperfections which is why we’d recommend opting for something in the middle like a satin finish.
WHAT KIND OF VARNISH SHOULD I USE TO VARNISH A FLOOR?
We used Granwax Aquathane varnish in satin and highly recommend it.
It’s what we used on all of our floors and is the same product that the professional floor sanding company used, too. We love it because it’s really easy to apply, dries quickly and has a great natural looking finish that doesn’t have that plastic-y look and is extremely hard wearing.
HOW LONG SHOULD I WAIT BEFORE VARNISHING A FLOOR?
Your floor is essentially unprotected after sanding. You should aim to get it varnished (or oiled) as soon as possible.
HOW MANY COATS OF VARNISH SHOULD I APPLY?
The manufacturer’s guidelines will vary, but as a rough guide around 3 coats for normal traffic areas and an extra fourth coat for high traffic hallways like hallways is what you should be aiming for.
HOW LONG BEFORE I CAN MOVE MY FURNITURE BACK INTO THE ROOM?
You shouldn’t move your furniture back till the varnished is entirely cured, which (depending on your varnish) can take up to 14 days! In most cases, this obviously isn’t possible and we only waited about 48 hours for most of our furniture.
How long does it take to sand a room?
Don’t underestimate the amount of time it will take to sand your floor. The professional floor sander guy took around 2-3 hours to sand our living room floor – it took us a lot longer! In numbers, it took the two of us about 25 hours to sand 4 rooms (totalling at about 43m²). If you had just one room the same size, it probably wouldn’t take as long, as you’d have fewer edges and less manoeuvring to do.
How long does it take to varnish a floor?
Varnishing the floor was surprisingly quick. I’d say it didn’t take us much longer than an hour to varnish all rooms once.
Cost of sanding floors
How much does it cost to sand a wooden floor?
We paid about £250 to have our living room floor (about 15m²) sanded and varnished. That works out at around £17/m². As a DIY job, the cost will depend on how many rooms you are doing in one go.
This is the cost breakdown of our epic floor sanding effort (dining room, hallway, first-floor landing & guest bedroom):
- The machine hire cost – Weekend hire floor sander and edge sander (Friday 14:00 – Monday 12:00) – £52.50 (special half-price offer)
- Large sanding sheets – £69.60
- Small sanding disks for edging sander – £46.80
- Varnish (we still had some leftover from our staircase restoration, so only needed one extra can) – £40.00
- Dust Masks – £4.18
Total: £213.08 – That works out at around £5/m².
How does the floor hold up? Are there any dents and scratches?
Our floor is holding up really well. In general, we don’t really wear shoes in the house, which is probably something that helps keep the floor looking good. Of course, there are a few dents and scratches, but they kind of add character to the floor and because we chose a clear varnish they are almost not visible. If you have a dent that really bothers you, you can check out our guide to fixing it here.
How do I maintain the floor?
We just give it a regular vacuum and wipe down with a damp cloth. Really nothing special.
How long will it last?
As a general rule, you should think about refinishing your floors when you redecorate. Refinishing it doesn’t mean that you have to go to all of the sanding efforts again. It’s more a case of lightly sanding the surface and revarnishing it.
Tips & Tricks
Will it be dusty?
Yes. It gets everywhere. Try and seal off the room you are working is as much as possible. On a positive note, the dust is really light and easy to vacuum and clean away. As I mentioned above, it’s a good idea to invest in a robust vacuum cleaner. We love our Kärcher vacuum cleaner – it’s indestructible and super affordable (well, so far at least!).
Is it a DIY job or would I be better off getting a professional to do it?
It’s totally DIY-able, but be warned, it’s really, really hard work. The sanders are really heavy and I just wouldn’t have been able to lift the machine out of the car and into the house on my own.
Is there really a difference between a professionally sanded floor and a DIY sanded floor?
Having had some of our floors professionally done and having done some by ourselves, we can happily say that there is absolutely no difference.
Should I fill the gaps between the floorboards?
The gaps between our floorboards aren’t very large and we didn’t bother filling them. We have however insulated under our floors and also insulated the gaps between the skirting boards and floors.
Should I decorate the room before or after sanding?
Really it’s up to you. We’d recommend doing any of the dirty work like stripping wallpaper and skimming before sanding the floor, other than that it really doesn’t matter. When sanding around the edges of the floor, you will inevitably knock your skirting boards, though, so finishing them off after sanding the floor is probably a good idea.
Do you have any tips for us?
Don’t underestimate the work required! Keep an eye out for offers. Some hire shops seem to have half price or 3 for 2 events. It’s really noisy – don’t plan on doing the work if your neighbours are home!
We hope that our guide on how to sand wooden floors has helped you! If you have anything else you’d like to know, just drop us a line, we’d love to help if we can!