Table 3. Core sample findings for roof D2.
Moisture
content
Thickness
(% of
TRR
Core
Insulation
(in.)
dry weight)
(%)
Status
3
EPS
2
430
69
WET
3
FGL
2
0
100
dry
3
FGL(frozen)
2
406
18
WET
6
EPS
2
568
62
WET
6
FGL
2
0
100
dry
6
FGL
3
0
100
dry
6
FGL(frozen)
2
429
16
WET
7
EPS
2
1010
41
WET
7
FGL
2.5
0
100
dry
7
FGL
2.5
1
99
dry
7
FGL
2
0
100
dry
12
EPS
2
2
100
dry
12
FGL
2
0
100
dry
12
FGL
2
0
100
dry
12
FGL
2
1
99
dry
Notes:
Core 3: An additional 3-in. layer of frozen fibrous glass insulation was present below the
bottom of this core. It also had lost most of its insulating ability.
Cores 7 and 12: No frozen fibrous glass insulation here. It was all dry.
Table 4. Roof cut B, test results.
Moisture
Thermal resistance
content
Thickness
Density
(% of
As
After
TRR
(lb/ft3)
Insulation
(in.)
dry weight)
received
drying
(%)
EPS
2
1.0
3337
1.8
7.1
25
FGL
2
8.6
9.0
7.0
7.5
93
FGL
2
5.6
1.1
10.1
9.9
102
Notes:
An additional 3-in. layer of frozen FGL existed below the two layers sampled. It was full
of ice and could not be removed intact for testing. Core 6 sampled similar material that
had lost most of its insulating ability.
and when this freezer is warmed up, such air in-
ROOF D3
filtration paths should be blocked.
The wet and dry thermal resistance measure-
This roof consists of a ballasted EPDM mem-
ments made of cut B (Table 4) indicate that the EPS
brane, expanded polystyrene insulation (2 in.), an
insulation there had only about 25% of its dry in-
old bituminous built-up membrane, fibrous glass
sulating ability. At adjacent core 3, the EPS con-
insulation (7 in.), and a concrete deck. As shown
tained much less moisture (430% by weight vs.
in Figure 2, the middle third of this roof is over a
38F (3C) cooler and the rest is over 0F freezers.
3337% at cut B) and had about 69% of its insulat-
ing ability (Table 3). By either measurements the
Roof D3 is separated from roofs D2 and D4 by ex-
EPS was quite wet and had lost a significant por-
pansion joints. The one at D2 is visible just behind
tion of its insulating ability.
the individual in Figure 13. It is also shown in Fig-
11
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