What usage depends on
The amount of product needed depends on several factors at once. The most important is the absorbency of the surface, because an old, porous base takes much more than a smooth, new one. On top of that come the texture, the number of coats and the type of product itself.
That is why a single universal figure does not exist. The coverage of the specific product is given on its data sheet, and the real usage on your surface is best confirmed with a test.
How to measure the area
The basis of any calculation is the area in square metres. For simple shapes it is enough to multiply length by width. Harder surfaces are worth dividing into rectangles, calculating each one and adding the results.
- Driveway and terrace of pavers. Measure length and width, and divide an irregular outline into simpler figures.
- Facade. Calculate the wall area, then subtract windows and doors if you want a more accurate result.
- Roof. Remember that the area of the slope is larger than the footprint of the building from above, because the slope is inclined.
Tip
Write the measurements down straight away. On larger or irregular surfaces it is easy to lose track, and one mismeasured wall can noticeably change the result.
The role of the calculator and product data sheet
With every product in our shop you will find a consumption calculator. You enter the area in square metres and the calculator converts it into the number of litres needed, taking into account the coverage of the given product. We also state the coverage of the pack directly on the product data sheet.
This is the most convenient way, because it calculates for a specific product rather than by a general rule. If you plan two coats, remember to take that into account.
Why the test is the best measure
No calculation replaces a test on a piece of the surface. By applying the product to a small, known area you see how much really comes off, on your specific surface. This is especially useful on absorbent, old and unusual bases, where theory differs from practice.
What reserve to plan
It is worth calculating with a small reserve. It is better to have some product left over for touch ups and a second coat in the most absorbent spots than to run out in the middle of the work, especially when it is hard to get exactly the same product and batch later.
Calculating usage step by step
- 1Measure the area. Calculate the square metres by dividing difficult shapes into simpler figures and adding the results.
- 2Check the coverage of the product. Look at the data sheet of the product or use the calculator by the product.
- 3Account for the number of coats. If you plan two coats, double the requirement for the areas that need them.
- 4Do a test and adjust. Apply the product to a known area and check the real usage, then correct the calculation.
- 5Add a reserve. Allow a small reserve for touch ups and absorbent spots, so you do not run out of product.
Frequently asked questions
How do I know the coverage of the product?
We state the coverage on the data sheet of each product, and by the product you will find a calculator that converts the area into litres. These are figures for a specific product, not a general rule.
Does usage depend on the surface?
Yes, very much. An old and porous base absorbs much more than a smooth and new one. That is why a test on your specific surface gives the surest measure.
How much product reserve should I plan?
A small reserve for touch ups and a second coat in absorbent spots is sensible. This way you avoid running out of product in the middle of the work.
How do I calculate the roof area?
Remember that the area of the inclined slope is larger than the footprint of the building from above. Calculate the area of the individual slopes by dividing them into simple figures and add the results.
