“Avoid it at all costs”, they said. With hindsight, this advice was sound. But, if like us you want to save a few hundred quid by sanding your floorboards to return them to their original glory, read on.
A few days after getting the keys to our place, we agreed that the dark brown, scuffed varnish downstairs had to come up and that we wanted to reinstate the original pine floorboards in our bedroom that were carpeted. After large amounts of Googling/YouTubing, it transpired that plenty of people hire industrial sanding machines as it costs a shed load to get it done professionally.
Hammering down nails
If your floors are anything like ours there’ll be a fair amount of prep work before the sanding can begin. Firstly, all nails need to be hammered down by at least 3mm, ideally 5mm, below the floorboard surface with a hammer and nail punch. This may seem like a lot, but the sanding process takes up a fair amount of wood so before you know it the nails will be flush with the surface again. The consequence of not hammering down nails is multiple torn sanding sheets which will cost a lot and the risk of damaging the sander. We learnt our lesson after we sadly lost 2 sanding sheets to raised nails RIP (excuse the pun.)
Filling holes & gaps
If your floorboards are old they’ll likely feature some sizeable gaps. Our upstairs floorboards are from the 1930s and so some gaps were as big as 7mm. We decided to fill these gaps by inserting some pine slivers to cover the gaps and stop potential draught. After buying a pack of pine slivers of various widths from eBay, I got to work matching the slivers to gaps and cutting them down to size with a hacksaw. After that, I dabbed some PVA onto either side of the sliver and tapped them into place. Not an issue if there’s a decent chunk of sliver protruding – once the PVA has dried, you can use a chisel to take off the excess without having to worry about it being perfect as the sanding process will sort this.
For more awkward gaps & holes, we used some Ronseal natural-coloured wood filler. This worked pretty well although it’s worth being aware that if you use a clear varnish like we did, this wood filler is likely to stand out.
Other prep stuff
Before any sanding, seal the room off with dust sheets. Honestly, you are not going to believe the mess this job causes so it’s worth being forensic with how you put these up (we were not and 3 months later are still finding dust in rooms we didn’t sand…)
The last piece of advice is entirely optional but strongly advised. Unless you live half a mile from your nearest neighbour, give them a heads up that you’re going to be making A LOT of noise. We did this and after the week was up bought them a bottle of wine as it must have been horrendous.
We decided to hire both a floor sander (for main sections of floor) and an edging sander (to get as close to skirting boards as poss). There’s a fair few hire places to choose from but we opted to go through National Tool Hire as they had decent reviews and were competitively priced. They were okay overall but initially gave us the wrong sanding sheets which meant a bloke had to drive round with the correct sheets so definitely check what they’ve given you before taking your sanders home!
What/how much sanding paper?
We sanded around 50 sq. metres of floor, most of which had a thick dark varnish on that was a bugger to get off. We started off in every room with 40 grit paper (the most coarse), then 80 grit, and finally finished with 120 grit to give a smooth finish. It’ll depend on the condition of your floor, but on the floor sander we used 7 x 40 grit, 6 x 80 grit and 3 x 120 grit. It’s definitely worth switching the paper out regularly as you’re wasting your time if you try to get too much out of one sheet.
As for the edging sander, we had a ‘mare with it. Whatever we did, the sander just burnt holes into floorboards and had a mind of its own. After multiple attempts and even getting a guy out to check it it was working correctly (he too struggled), we ended up not using it. This was frustrating but fortunately we had a finishing sander and corner sander (around £30 each from B&Q) which did a good, if very slow job of sending edges and corners. I reckon the edging sander we had wasn’t working correctly so probably still worth hiring one yourself, but just be aware of this potential issue.
We hired 5 dust bags for each sander but you can actually reuse them so if I did it again I’d probs just hire a couple.
As far as the actual job of sanding goes, it’s pretty simple:
- start with the most coarse grit (likely 40) and work up to finer grits
- ALWAYS sand in the direction of the floorboards, even if it’s tempting to sand across them as you’ll leave horrible marks if you go against the grain
- move the sander smoothly and consistently to avoid sanding dips or marks into the floor
- if you’re sanding a floor that’s already been varnished, be prepared to get through a lot of the coarse grit (40) sanding sheets as the varnish will make them gammy in no time
- Before you spend hours sanding right up to the skirting board, bear in mind that if you’re adding moulding to cover the gap between floorboards and skirting board, this area will be covered so no need to sand (we added a 12mm pine scotia moulding)
As we had 4 rooms to sand we hired the equipment for a week and took some days off work and it’s a good job we did as between us the 4 rooms took us 4 full days. It doesn’t need to be 2 man job but it’s certainly helpful from a sanity POV to have someone sharing the experience with you. Plus the sanders are well heavy.
Hiring both sanders, a shed load of sanding sheets and several dust bags cost £268 for the week BUT as with most hire places, you get refunded for any sheets and bags that you don’t use. I’d recommend ordering a lot more than you think you’ll need. We ended up getting £122 back so the total hire cost came to £146 which is really pretty good. On top of this, we used a humongous amount of electricity as these are serious machines and we ran them for hours. I can’t say exactly what the electricity cost was but I would estimate £100 – £150 so bear this in mind.
The finished product
Eventually you’ll be left with a beautiful looking, smooth floor and can feel pretty smug about having saved yourself a decent wad of cash. However, you don’t want to be leaving those floorboards naked for long because they’re very sensitive beings and will damage easily, particularly if they’re pine like our floors. So, next step is to treat the floor – we opted to varnish ours.
For more info, here’s a great article by Little House on the Corner with more info about DIY floor sanding.
- Dust sheets
- Floor sander with coarse, medium and fine sanding sheets
- Edging sander with coarse, medium and fine sanding sheets
- Corner sander with coarse, medium and fine sanding sheets
- Ear plugs
- Face mask
- Knee pads
- Nail punch
- If filling gaps:
- Wood slivers
- Wood filler