The short answer
Hardwax oil is sold by the litre and used by the square metre, which is why the price on the tin tells you almost nothing. Oslek LED Hardwax Oil covers 40 to 50 square metres per litre by hand, or 70 to 80 by machine. That works out at roughly £3.00 per square metre hand applied, or £1.80 by machine, ex VAT. Most hardwax oils cover 20 to 30 square metres per litre per coat, and most need two coats. A cheaper tin with half the coverage costs you more.
Two tins sit on a shelf. One is £80 a litre, the other £135. The choice looks obvious until you read the coverage, and then it reverses.
Why the price on the tin misleads
At 20 square metres per litre, the £80 tin costs £4.00 for every square metre you cover. At 45 square metres per litre, the £135 tin costs £3.00. The expensive one is the cheaper one, by a quarter, and the gap widens on every job you do.
This is the most common mistake we see when someone is pricing a floor. It is also the easiest to correct, because the maths takes about ten seconds.
How to work out what you need
- Measure the area in square metres. Length times width for each room, added together.
- Divide by the coverage per litre. The figure is on the technical data sheet.
- Multiply by the number of coats. Check whether the data sheet quotes coverage per coat or in total. Most quote per coat.
- Add about 10 per cent for waste, edges, offcuts and what ends up on the rag.
Worked example. A 60 square metre floor, hand applied at 45 square metres per litre:
60 ÷ 45 = 1.33 litres, plus 10 per cent = about 1.5 litres
At the 5 litre price that is roughly £194 of material for the whole floor, ex VAT.
What drives coverage
Coverage is not a fixed number, which is why every data sheet gives a range.
- Porosity of the timber. Open grained oak drinks more than a dense, closed grain species.
- Preparation. Sanding to a finer grit closes the surface and reduces uptake. Finishing at 120 grit suits most floors.
- Application method. A machine lays a thinner, more even film than a hand pad, which is why machine coverage is close to double.
- Number of coats. A second coat always uses less than the first, because the surface is already partly sealed. On our own flooring guide we put the second coat at 10 to 20 per cent of the first.
Oslek LED Hardwax Oil, per square metre
All figures ex VAT, based on 40 to 50 m²/L by hand and 70 to 80 m²/L by machine.
| Pack | Price ex VAT | Per litre | Hand applied | Machine applied |
|---|---|---|---|---|
| 1L | £135.00 | £135.00 | £2.70 to £3.38 per m² | £1.69 to £1.93 per m² |
| 5L | £648.00 | £129.60 | £2.59 to £3.24 per m² | £1.62 to £1.85 per m² |
| 10L | £1,295.00 | £129.50 | £2.59 to £3.24 per m² | £1.62 to £1.85 per m² |
How published coverage compares
Every figure below is the manufacturer’s own published coverage, taken from their technical data sheet or product page. Read the coats column alongside it, because most of these are quoted per coat and most specify two.
| Product | Published coverage, m²/L | Per coat or total | Coats specified |
|---|---|---|---|
| Oslek LED Hardwax Oil | 40 to 50 hand, 70 to 80 machine | Per application | 1 to 2 |
| Rubio Monocoat Oil Plus 2C | 30 to 50 | Total | 1 |
| Loba HardwaxOil | 50 trowel, 20 roller or brush | Per coat | 2 minimum |
| Whittle Waxes Evolution | Up to 30 | Per coat | 2 |
| Osmo Polyx-Oil Original | 24 roller, 30 brush, 60 machine | Per coat | 2 on new work |
| Fiddes Hard Wax Oil | 20 to 24 | Per coat | 2 maximum |
| Bona Hardwax Oil | 20 to 24 | Per coat | 2 |
| WOCA Hardwax Oil Extreme | 20 | Per coat | 1 to 2 |
Odie’s Oil Universal Finish is often quoted around 65 m²/L. Odie’s does not publish a metric figure. That number is a conversion of their claim of 21 to 25 square feet per ounce on domestic hardwoods, and their own material quotes considerably higher figures on dense exotics. We have left it out rather than present a converted number as a published one.
Two things are worth reading off that table.
Most hardwax oils land between 20 and 30 square metres per litre per coat, and most need two coats. Multiply it out and a 24 m²/L product is covering around 12 square metres of finished floor per litre.
Application method moves the number as much as the product does. Osmo publishes 24 by roller and 60 by machine for the same tin. If you are comparing products, compare like with like, or the tool you happen to be holding will decide the answer for you.
The column that is not on the table
Cost per square metre is the right unit for material. It still is not the whole cost.
A finish needing 12 to 24 hours before anything can be touched occupies rack space, floor space and a slot in your schedule for that entire time. We have written about what that actually costs in the real cost of slow drying coatings. For a workshop turning jobs around, that number is usually larger than the difference between any two tins on this list.
Frequently asked questions
How many square metres does a litre of hardwax oil cover?
It varies by product. Most hardwax oils cover 20 to 30 square metres per litre per coat, and most need two coats. Oslek LED Hardwax Oil covers 40 to 50 by hand and 70 to 80 by machine.
How do I calculate how much hardwax oil I need?
Area in square metres, divided by the coverage per litre, multiplied by the number of coats, plus about 10 per cent for waste. Check whether the data sheet quotes coverage per coat or in total.
Is a more expensive hardwax oil always worse value?
No, and often the opposite. Price per litre only means something once you divide it by coverage. A product at twice the price with three times the coverage is cheaper per square metre.
Does a second coat use as much as the first?
No. The first coat is absorbed by open grain. The second sits on a partly sealed surface. On our own flooring guide we put the second coat at 10 to 20 per cent of the first.
Does machine application really double the coverage?
It gets close. A machine lays a thinner, more consistent film than a hand pad, which is where the jump from 40 to 50 up to 70 to 80 square metres per litre comes from. Osmo publish a similar jump for their own product.
What does LED Hardwax Oil cost per square metre?
Roughly £3.00 per square metre hand applied and £1.80 by machine, ex VAT, at 5 litre pricing.
Related guides
- Timber coatings: the full guide: the whole subject in one place, with every guide linked from it.
- The real cost of slow drying coatings: what drying time costs you in racks, floor space and labour.
- Flooring application guide: the full method, from bare boards to foot traffic the same day.
- Clearing the air on VOCs: what solvent content means for an occupied building.
Working out a job? Tell us the area and we will tell you what you need.
Explore LED Hardwax OilsAsk us about a project