of Laths and the like therefor.
Year: 1888

page_text: of Laths and the like therefor.
I, WILHELM DOEHRING of Leipzig in the Empire of Germany, Director of
Building to the Prussian Government and Director of the Fire Brigade of the City
of Leipzig, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement :-.
This invention relates to plastered constructions such as ceilings, partition walls and
the like in which a frame work or support of laths or wooden boards etc. is made to
hold a plaster covering surface. Heretofore, the plaster has adhered to the wood in a
solely mechanical manner and more or less imperfectly in places only so that it is
liable to be easily detached more especially in case of fire. The interstices between
the laths and the combustible nature of the latter are also facilities for the spread
of fire.
The object of this invention is to render the laths fire proof and to prepare them
(or such other wooden supports as may be used in place of laths) for the plastering
in such a manner that the plastering may adhere more firmly by reason of combining
mechanically or chemically with the matters with which the wood is covered or
impregnated, instead merely by adhesion to the surface thereof as heretofore.
The following is the improved process Laths, boards or wooden sticks of any
suitable shape of cross section and not necessarily provided with grooves, are soaked
or impregnated with Chloride of Calcium or of lime and soluble glass, they are also
coated with soluble glass to which may be added Baryta and Zincpowder. Such
laths or the like may then be fastened in the usual way with or without interstices
between them. Such laths are rendered uninflammable by the formation of silicate
of lime in the wood and their surface is also specially adapted to chemically combine
with silicious matters such as sand gravel and the like. The coating or plastering
containing the sand, gravel, or the like which is to be spread upon the laths is
intended to form a hard and rough surface which also has the property of combining
chemically with the plastering afterwards laid thereon so as to hold the same securely
in place over all its surface. The aforesaid preliminary rough surface coating or

page_text: plaster is made as follows-A mixture is made of powdered carbonate of lime (chalk)
hydraulic lime, infusorian earth, oxyde of Zine, magnesia, powdered flint and powdered
fire brick, sharp sand rich in silica and soluble glass. This mixture sets firmly on the
surface of the laths as aforesaid and forms a rough surface to which the usual
plastering firmly and permanently adheres. The sand or gravel need not be added
to above mixture but may if desired by spread upon the mixture after it is laid, and
pressed therein to form a rough surface thereon, if desired.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what
I claim is ;-
In plastering.
1.) The coating of the surface to be plastered with a mixture adapted to set with
a rough surface and to combine chemically with the plastering laid thereon.
2). The coating of the surface to be plastered with a mixture comprising Chalk,
Infusorian Earth, Oxyde of Zinc, Magnesia flint, sand and soluble glass, and plastering
upon the surface thereof.
3). The preparation of laths by impregnating with soluble glass and chloride of
calcium or of lime and coating with soluble glass, baryta and zinc powder for the
purpose set forth.
Dated this 20th day of November 1888