Number
293-EN
Section
General Section
Use
Sector
Building and construction work
Function
Other
Process
Other
Product category
Fillers, putties, plasters, modelling clay
Abstract
The advantages of clay plasters such as versatility, flexibility, ease of application and cost-effectiveness make them a practical alternative to gypsum based plasters. Further, clay plaster has excellent properties, regulating both temperature and humidity, making it ideal for breathable constructions.
Substituted substances
Calcium dihydroxide
CAS No. 1305-62-0 EC No. 215-137-3 Index No.
Chemical group
Hydroxides
Calcium sulfate
CAS No. 7778-18-9 EC No. 231-900-3 Index No.
Chemical group
Sulfate
Alternative Substances
Clay
CAS No. EC No. Index No.
Chemical group
Clay minerals
Reliability of information
Evidence of implementation: there is evidence that the solution was implemented and in use at time of publication
Hazard Assessment
According to the producer gypsum plaster is irritating to respiratory system, eyes and skin and has risk of serious damage to eyes. The ingredients are not included in Substance Database according to SUBSPORT Screening Criteria (SDSC). Alternative product has no classification according to the producer and it is not listed in the SDSC.
Description of Substitution
Clay is one of the earliest basic building materials used. But now it is recognised as being a thoroughly modern and convenient building material with outstanding natural properties. This case story illustrates the use of Claytec fine finish coat plaster instead of gypsum plasters. During the renovation of old houses and on new construction gypsum plaster can be replaced by clay. Eventually, the whole house could be plastered with clay. According to the supplier use of ecological building materials on private houses is increasing constantly.
The natural finish coat is made from clay, sand and plant fibres and gives a fine, slightly textured finish. Plaster can be applied evenly with a Japan trowel or other stainless steel trowel, or alternatively with a plaster-spraying machine to a thickness of approx. 2 mm. Allow pre-drying, depending on the background possibly several hours, and then finish the surface by rubbing evenly with a sponge float. It can be left as a natural clay colour or painted with natural paint.
Clay?s natural breathing property of absorbing and diffusing water vapour and heat, helps offset swings in humidity and temperature. Clay also absorbs odours and is an effective sound insulator.
In the construction industry there are also other products containing clay: undercoat plaster, medium finish plaster, paints and plates.
Case/substitution evaluation
Gypsum based plaster has hazardous properties to respiratory system, eyes and skin and can be replaced with a safe and a natural origin alternative.
State of implementation
In use
Date and place of implementation
2012 in Germany
Availability ofAlternative
on the market
Producer/Provider
See: Contact: Information supplier
Type of information supplier
Producer / distributor
Research
Contact
Further information
You will find more information about clay building here:
http://www.fachwerk-maler.de/lehmbau.htm
Date, reviewed
March 1, 2013