Short answer: on acid-resistant surfaces (e.g. granite, clinker, porcelain stoneware), efflorescence is removed with an acidic special cleaner such as stone clear SF 79 Limescale and Efflorescence Remover: pre-wet the joints, apply the solution at 1:10 (for heavy deposits 3–5:10), work with a pad or brush and rinse thoroughly with water. On marble, limestone and other calcareous stone, acid is off-limits – here we will advise you individually.
What is efflorescence?
Efflorescence is a white deposit of lime and salts. Moisture dissolves them in the mortar, concrete or substrate and carries them to the surface. There the water evaporates – leaving a white residue. It is typical on new patios, steps, walls and balconies.
Which product?
| Situation | Product |
|---|---|
| Efflorescence, limescale, cement haze outdoors on acid-resistant surfaces | SF 79 Limescale and Efflorescence Remover |
| Efflorescence and cement haze indoors and outdoors on acid-resistant stone | ZE77 Cement Haze Remover |
| Marble, limestone, travertine, cement slabs | No acid – ask for advice |
Guide: removing efflorescence with SF 79
- Check the material and test in an inconspicuous spot.
- Pre-wet: thoroughly wet non-acid-resistant joints with water.
- Mix the solution: light soiling 1 L SF 79 to 10 L of water, heavy soiling 3–5 L to 10 L of water. Undiluted if necessary.
- Apply and work in: treat stubborn deposits with a pad or brush – by hand or with a single-disc machine. On walls, work from bottom to top.
- Rinse: rinse thoroughly with clean water.
Coverage: 10 L of working solution for approx. 30–50 m². Wear protective gloves, safety goggles and, when spraying, respiratory protection. Metal and calcareous stone are attacked.
Does efflorescence come back?
As long as moisture carries salts from the substrate, new efflorescence can form – especially on new surfaces. It often decreases over time. A water-repellent sealer such as SB 56 Water Repellent reduces water penetration from above without closing the pores.
Frequently asked questions
Can I just brush efflorescence off?
Loose salts can be brushed off dry. Firmly attached lime efflorescence needs an acidic cleaner – on acid-resistant stone.
What is the difference from cement haze?
Cement haze forms directly when laying and grouting. Efflorescence migrates up from the substrate later. More on this: Removing cement haze.
Does vinegar help against efflorescence?
Vinegar has only a weak effect and attacks calcareous stone and cement joints. A specialist product is more effective and can be dosed more precisely.
Advice
Not sure what stone is installed? +41 41 790 38 05 · Cleaning by StoneClear
