Frequently Asked Questions

Which bases are suitable?

All mineral bases

How do I prepare the base? (for unplastered walls)

Stone walls of differing textures or raw coating concrete must be freed of dirt dust and loose pieces. When using plaster bases and renders the instructions from the manufacturers prevail.

What do I do with different bases?

Differently absorbent bases can dry out differently!
Bases made from bricks, lightweight perforated brick, chalk, sand and lightweight concrete stones should be well dampened previously and a mortar cement spray from mortal group PIIIa (mixed grain sized suggestion) applied by hand or with a plaster machine over the entire surface. Then, before continuing to apply the plaster leave to dry for at least two days (white colouration).

How long does it take to dry?

A chalk paint, or Klimasan-Mox, is already dry to the touch after a few hours, whereas a Chalk perlite plaster (base layer) should only be reworked after 3 weeks.High grade lime plaster is dried out after 24 hours depending on base, temperature and air humidity.

Can I use chalk for exteriors and interiors?

Depending on the product (e.g. Klimasan-Antik, a thick layered chalk render complying with DIN18550-1) chalk is suitable for interiors and exteriors.

As the end user can I apply all chalk products myself?

It depends on the skill of the “end user“, as to whether they can apply the Klimasan Plasters or fillers (Klimasan-Mox) themselves.

Can I decorate on chalk?

After the rubbing down/whitewashing of the base it is possible to decorate again.

I have found a crack in my wall!

A crack is not always a crack! Hairline cracks up to around 1mm in chalk always pop up. Larger cracks should always be inspected by a professional.

What does the PH value mean exactly? And what is it good for?

The term pH derives from pondus Hydrogenii or potentia Pydrogenii (Latin: pondus = weight, Latin: potentia = strength, Latin: Hygrogenium = hydrogen).The pH value is a measure for the acidic (low) or alkaline (high) reaction or a water solution.Briefly said the higher the pH value, the better!Klimasan-Perlit plasters have a pH value of 12. On a high pH base, organisms like mould fungi, bacteria or algae (on exteriors) can’t grow well! Gypsum, synthetic plasters or dispersions in contrast lie in the neutral area at 5-7 and are an optimal base and food source for mould!

Reicht es zur Schimmelbekämpfung wenn ich einfach mit Kalkfarbe streiche?

Nur mal drüber streichen ist nicht die Lösung! Es wäre nur eine kosmetische Behandlung! Wichtig ist, die Ursache vom Schimmel zu beseitigen (z.B. Wassertropfen auf der sperrenden Oberfläche = klimasan-MoX) und / oder den Untergrund wärmedämmen und kapillar aktiv (= Perlit-Putz) ausführen.

Is it enough to just use the anti-mould spray against mould?

No! Anti-mould spray is like the chalk paint: just using this is not the solution. Anti mould spray serves to kills mould and disinfect, afterwards a renovation must be undertaken.

Why chalk and not gypsum?

Gypsum is not just neutral with a PH value of 5-7 but also had the bad feature of taking in water and storing it for a long time. If gypsum stays damp for a long time, it begins to rot. Gypsum has poor sorption behaviour (absorbing and letting out liquids). Chalk however has good sorption abilities!

Is there anything important to take not of during the application? Safety!!!!

Highly alkaline products are corrosive in their fluid state, avoid skin and eye contact at all costs. Always refer to the safety information sheets!

Have you found stains on glass, wood, metal etc.?

Splashes should be washed away immediately, as otherwise the respective places burn (corrode), careful coverage is always recommended! Clean the surfaces and tools with clean water.

What is the difference between natural paints and plasters compared to the conventional ones?

Have a look at the ingredients of the respective products, just to see what is actually in it! Unfortunately, it is that every plaster or paint manufacturer can call their products “mineral”, even when they only have up to 5% synthetic dispersion.

With chalk it is so that every manufacturer can write chalk on their product when it only contains 3% chalk!

A few examples of ingredients that conventional “normal” paints and plasters can contain.

Settling agents, anti-skinning agents, defoamers, catalysts, preservatives, wetting and dispersing agents, drying agents, thickeners and thixotropic agents, levelling agents, viscosity stabilizers, algicides, fungicides, and then they usually contain “processing agents”, whatever they are. Klimasan products are pure mineral products with an organic content of <1%. They contain no chemical additives. We offer a full declaration of all products. Building that are equipped with Klimasan products receive the DGNB GOLD certificate (= “world green building council”).

Can I apply Klimasan-Perlit directly on existing plaster?

With Klimasan-Perlit needs a mineral and stable base! If you want to just use it as a buffer e.g. on “Fachwerk” timber frame buildings or old plasters, you have to use a plaster base (e.g. Welnet plaster)! For mineral bases a spray is enough.

Does Klimasan-Perlit plaster need a net cladding?

Basically no, as perlite has a so called “Pozzolan” (=hardening aid) effect and the surface of the Klimasan-Perlite plaster gets very hard. If the base is however, problematic, or when plastering over a timber frame we recommend for example include in the render a reinforcement as follows:
1. Base (Klimasan-Perlit plaster) well pre dampen, around 3-4mm of render apply and “iron over” glass fibre fabrics (e.g. 5×5)
2. The next day complete with 2-3mm e.g. chalk render