You will find answers to many of your questions here:
Can Lime wash be used outdoors?
Stoopen & Meeûs Lime wash suitable for outdoor use as façade paint. It is important to note that apart from its ecological and traditional character and allure, there are certain disadvantages.
Lime wash is an absorbent paint, which will absorb dirt more quickly
After some time in the outdoor air, Lime wash cobaltoxide = cobaltoxide
will always show some powdering.
Lime wash can only be painted over with Lime wash.
How much Lime wash is needed?
Usage is determined by the substrate, the moisture-content of the substrate, the dilution of the Lime wash and the painting technique.
As a specification, we advise:
Indoors: 0.5 kg/m², on smooth plastering
Outdoors:1 kg/m2 on façades, unless a brush-stroke structure needs to be applied or deeper grouting makes proper brushing off difficult.
Once you have started work (after about 10 m²), it is advisable to check the usage and possibly add some extra moisture to the substrate, or to dilute the Lime wash a bit more.
How to choose a Lime wash colour?
The colour of the Lime wash is determined by the degree of absorption of the substrate. Strongly absorbent substrates will yield a darker colour. This causes the typical colour nuances in the mineral Lime wash. This makes the colour chart indicative.
On non homogenous substrates (indoors), a water-borne primer can be applied first to make the absorbency uniform.
The intensity of the mixing action will also yield a difference in colour. The more intense the mixing action, the darker the colour.
Longer brushing will also yield darker colours and more colour nuances.
It is advisable to paint a sample on the (moistened) substrate that is going to be painted and to point out to your client that colour nuances are a characteristic of mineral Lime wash.
How can Lime wash / Lime stucco be polished?
After it has set (1-2 hours), Lime stucco can be polished with an inox knife.
It is advisable to do this in consecutive steps during the drying process, depending on the desired result. Never polish stucco that has not settled properly too hard (risk of peeling)
The following possibilities can be distinguished:
Lime wash – Brushed and polished: apply 2 layers Lime wash with a rectangular brush. Once it has completely dried, the Lime wash can be polished with an inox knife. The uppermost parts will start to shine and become darker, the underlying areas will remain mat and lighter.
Stucco – Even colour, smoothly polished (tadelakt look): apply 2 to 3 layers, smoothing each one after there has been good adhesion. After the final layer polish ever harder in consecutive steps until you have a completely smooth surface.
Stucco – Varied colour, smoothly polished (tadelakt look): apply 2 to 3 layers, apply layers 1 and 2 roughly and strickle carefully after there has been good adhesion (do not smooth). The last layer will only fill in irregularities After the last layer polish ever harder in consecutive steps until you have a completely smooth surface.
Stucco – Varied colour, roughly polished: apply 2 to 3 layers, apply layers 1 and 2 roughly and strickle carefully after there has been good adhesion (do not smooth). After the last layer, allow to settle sufficiently and then polish without smoothing. The upper layer will shine, the underlying areas will remain mat and lighter.
All techniques in between are possible as well.
What creative possibilities does Lime wash offer?
Apart from creating stained and colour nuances through the brush technique, one can also play with pigments.
Colour nuances with brush technique: The harder one brushes the darker the colour becomes; because of this a brushed Lime wash will always show colour nuances.
Poorly mixed pigments: when brushed down poorly mixed Lime wash will have a ‘flamed’ appearance.
Mixing several colours : First apply a basic colour and apply wet in wet brushstrokes with another colour. Then gently brush out with the first brush.
Can Lime wash be removed or painted over?
Outside : Lime wash can only be painted over with Lime wash. (a thin layer is sufficient to freshen up colours and renourish old Lime wash).
Lime wash can be removed with a professional high-pressure cleaner (depending on the substrate).
Inside : apply primer and the Lime wash can be painted over.
How long will a badgeoned façade continue to look good?
This depends largely on the circumstances. A dusty environment, a run-off of rainwater, or dense plant growth will soil the badgeoned surfaces more quickly.
Kalei is a breathing, moisture-regulating and absorbent paint, comparable to a mineral one
After some time (5-10 years) Kalei needs to be freshened up with a new layer of Kalei.
Kalei will continue to look good for longer if a waterproof product is applied, however, the characteristic Kalei aspect will then disappear. Repainting the surface is really only possible once the product has all but disappeared.
How long will a Lime washed façade continue to look good?
This depends largely on the circumstances. A very dusty environment, a run-off of rainwater or dense plant growth will soil the Lime washed façade more quickly.
Lime wash is a breathing, moisture-regulating and absorbent paint, comparable to a mineral one.
After a period of time (5-7 years), or longer if you like a ‘Tuscany look’, the Lime wash needs to have a new fresh layer applied.
Lime wash will continue to look good for longer is a waterproof product is applied, however the characteristic Lime wash aspect will then disappear. Repainting the surface is only really possible once the product has all but disappeared.
Which substrate are suitable for Lime wash?
Outside: The substrate needs to be homogenous, mineral and absorbent, and dust- and grease free.
Non-homogenous substrates could show colour nuances because of the various absorption levels.
Façades that are not sufficiently absorbent (certain wire-cut-bricks with low porosity <5%), will not absorb the Lime wash as well, which will have a negative effect on the adhesion. Brick with a low porosity do no need to be moistened, or less so, beforehand.
Inside: Lime wash may be applied to many different substrates:
Porous substrate such as brickwork, plastering, concrete, etc.
Non-absorbent substrates like: old paintwork, wood, MDF, metal, etc., it is sometimes advisable to apply a grained primer beforehand.
What preparation is needed for the substrate?
Clean the substrate with a high-pressure cleaner. Remove all moss.
Moisten before applying paint (check for sufficient absorbency).
Do not apply any primer or impregnation as they inhibit absorption.
Façades that have been treated with water resistant products in the past are not suitable.
How to prevent block-formation when applying Lime wash.
Prevent block-formation by:
- Painting in irregular forms
- Well-moistened façades facilitate the spreading of the paint
- A diluted 2nd layer is easier to brush out (faster painting = less block-formation)
- Polishing afterwards may partly remove block-formation
What about bad grouting?
Lime wash is less suitable for damaged façades. We therefore recommend the use of our Badgeon here, because of its good properties as a filler.
Drying time of Lime wash?
The drying time is determined by several factors (climatic circumstances, thickness of the layer, substrate) and ranges between ½ an hour to 6 hours. When the weather conditions are misty or rainy, it could take several days.
When the colour of the Lime wash becomes lighter, it is hard.
Lime wash is air-hardening, and will harden through carbonation with CO2 in the air. This process can take from 1-3 months.
The drying time may be influenced by the moisture-level in the substrate.
Applying Duistemper in the full sun can cause the Lime wash to burn and thus reduce adhesion.
What if a white film appears on the Lime wash?
Lime wash Kalkverf should be protected from moisture until it has completely dried. It is recommended you do this for at least 72 hours.
Rain will damage areas freshly painted with Lime wash (white stains and running). Should this occur an extra layer of Lime wash will have to be applied.
Protracted staionary moisture can cause a white film (bleeding). This white film will be dissolved by rain and disappear.
New brickwork always carries the risk of bleeding. Bleeding is caused by salts from the stone or the mortar, which can be carried to the surface by moisture. These salts combine with the moisture in the Lime wash (which breathes and is absorbent) and form a white film once the water has evaporated
How long is Lime wash suitable for use?
Lime wash is air-hardening; once it has been mixed with water the Lime wash Kalkverf is suitable for use for a period of several months.
How is powdered Lime wash prepared?
Take the 20 kilo bag of base coat powder
Fill a tub with at least 8 litres of water
Add 1 to 3 pots of pigment (400 gr.) to the water and mix mechanically.
For a good homogenous mixture add only 2/3 of the Lime wash powder to the bucket (leave the powder to become absorbed) and mix at a high speed to create a homogenous mass.
If necessary add extra water to achieve the desired consistency, depending on the substrate and technique.