Perlite Plaster Aggregates Lightweight and
Insulating Tile Mortars
The widespread use of lightweight perlite aggregate to replace sand in tile mortars is easily understood when one studies the advantages that perlite has to offer. In addition to cost savings made possible by the reduction of labor and fatigue, tile contractors are able to give their customers better installations.
ADVANTAGES OF LIGHTWEIGHT PERLITE AGGREGATE:
ACCEPTED MIX PROPORTIONS FOR PERLITE TILE MORTARS
Several different mix proportions are used by tile setters but the
mix most commonly used is presented in the following table. All materials should be
thoroughly mixed dry and then sufficient water should be added to obtain the desired
consistancy. The use of excessive water should be avoided.
It is recommended that a thin coat of Portland cement paste be troweled or brushed over each previously soaked and drained tile before it is installed on a lightweight perlite mortar bed. This skim coat assures a satisfactory bond.
It is suggested that the tile setting bed be trowel cut both vertically and horizontally every three or four courses of tile to prevent cracking which may occur. Kitchen and lavatory ceilings may be easily tiled using lightweight perlite tile setting mortars. The lightweight of this mortar makes it much less tiring to trowel onto ceiling areas.
Kitchen and lavatory ceilings may be easily tiled using lightweight perlite tile setting mortars. the lightweight of this mortar makes it much les tire to trowel into ceilings areas.
Lightweight perlite tile mortars are especially suited for remodeling. The reduced weight of finished installations places a minimum of loading on old walls and the building structure.
An Update by Rick Drewes of Stonehenge Tile and Bathworks
The information on your web page is enough to show perlite is a viable aggregate (although the information is dated. Nowadays modified thinsets are used more than the old mudset procedures. We often use 25%-50% perlite per volume in Florida because most work is over slabs. With the newer technology of stronger and more flexible thinsets, however, I have had great success with the same percentages over wood floors as long as they have total ply-thickness of 1 1/4" and a minimun 2x10 on 16" centers.
I also have found it advantageous to "flat coat" plywood floors with straight modified thinset before applying a perlite mix coat for a good mechanical bond.
I am truly surprised more peole do not use perlite. It stretches thinset considerably.
Also, one of the main reasons I use perlite is because thinset is
aptly named --- you cannot go deeper than 3/8". Thinset shrinks as it dries and
perlite is the only thing I have found to use with larger tiles on floors to keep them
where you left them. (Without the perlite, the thinset can shrink a little---and
1/16" to 1/8" is a heck of a lot of shrinkage when installing a large marble or
Information given herein is from sources considered
reliable, but no guarantee of accuracy can be made or liability assumed. Your
supplier may be able to provide you with more precise data. Certain compositions or
processes involving perlite may be the subject of patents.