moisture entered the roof. We expect that a search
core 19 at the slit so that the patch made to seal
will find it within a 4-ft radius of the patch we
the core hole would also cover the slit.
made in the membrane where core 17 was taken.
Core 20 and cut H were taken where shown in
Figure 32 shows a photograph and thermogram
Figure 3. Figure 35 shows cut H being taken. Find-
where core 19 was taken. When the ballast was
ings of cut H are presented in Table 17. The phe-
moved aside to take core 19, it was noticed that
nolic insulation contained only a little moisture,
there was a lot of fine-grained soil on the mem-
which reduced its insulating ability by only a few
brane. As that soil was moved aside, a 1-in.-long
percent. The steel deck below contained a small
slit was found in the membrane (Fig. 33 and 34). It
amount of rust.
explains why insulation in this area is wet. We took
The acid released by phenolic insulation when
Figure 32. Photograph and thermogram of another strong thermal
anomaly on roof A2, looking north. Core 19, taken here, found wet