Page 203 - Construction Waterproofing Handbook

3.92 CHAPTER THREE
and sheet-goods are most commonly used. Clay systems are not applicable for interior
spaces; cementitious systems, however, make excellent choices, since these areas are not
subject to thermal movement (the one major disadvantage with cementitious product is
that they do not move under thermal expansion or contraction).
Shower and bath areas are common areas requiring waterproofing anytime they occur
above occupied spaces. Figure 3.90 details the application of a liquid-applied membrane
with the tile and setting bed acting as the protection or wearing surface for the membrane.
Note that the material is applied over a concrete substrate. While liquid membranes can be
applied over plywood, it is often preferable to use a sheet or cementitious systems in this
situation since the plywood joints are not sufficiently tight to apply liquid membranes.
Figure 3.91 details a sheet membrane installation and Fig. 3.92 details a cementitious and
liquid combination system.
These same systems can be used in kitchen or any other similar interior space where a fin-
ished floor that acts as a protection layer for the membrane is applied. Usually this finish
floor surface is a tile that works well in wet room areas. Figure 3.93 details the application
of a sheet application for the kitchen area. Note that the membrane is applied continuously
under the finished floor, including the interior partitions. This is a critical detail to prevent
the 90%/1% principal from applying to interior spaces as well. Running the membrane con-
tinuously under the interior partitions prevents water from entering the wall and bypassing
the membrane in the same manner as described for planters on plaza decks in the previous
section. Figure 3.94 details such a sandwich-slab application for interior projects.
In any area where an expansion joint is required, the joint should be detailed in the same
manner as sandwich-slab construction. The joint should occur on the finished floor as well
as the substrate on which the membrane is applied. Note this detailing in Fig. 3.95.
If necessary, these waterproofing systems can be used to completely envelope a room, as
is the case with the steam room detailing shown in Fig. 3.96. For any interior application, the
same installation precautions should be used as with above- or below-grade applications.
Specific guidelines for interior applications should be requested from the manufacturers; for
instance, whether or not thin-set tile can be used directly over the membrane.
Thin set tile adhering directly to a waterproofing membrane obviously deters from its
movement capability. However, since the movement experienced inside a building is not
as much as on an exterior envelope portion, most manufacturers will accept a thin-set
application for interior areas.
A major problem with many interior waterproofing application is the amount of traffic
from different trades that might occur on a waterproof membrane before it is protected
with the finished floor or wall surfacing. For example, after a membrane is installed, var-
ious trades might be required in the room, such as electrical or mechanical, before the fin-
ished surfaces can be applied. As such, it is imperative that protection be provided on the
waterproofing membrane until such time as the finished floor or wall surfaces can be
applied properly over the membrane.
The general contractor should carefully examine the membrane before application of the
finish systems, to ensure that the waterproofing membrane is intact and has not been dam-
aged by PPes over the membrane and to verify that it functions properly. This will prevent
costly repairs such as removal and replacement of tile to fix an interior membrane application.
Flood tests consist of temporarily damming the drains in the room, flooding the deck with