Install Instructions

11
IM-PR 566442 1114 (Design Manual)
1.3.1 Residential insulation recommendations
1. Perimeter insulation may be applied on the interior or exterior of the foundation. Perimeter insulation
should be applied vertically if the top of the slab is within 12" of grade, and may be applied vertically
and / or horizontally if the top of the slab is more than 12" below grade. Listed depths are measured
from the top of the slab. Viega also recommends installing a minimum R-5 horizontal foam board
insulation under the entire slab for small residential applications (< 2,000 ft
2
).
2. R-value should be a minimum of 5 times the value of the floor covering’s R-value.
3. Or maximum R-value permitted based on the depth of the floor joist.
1.3.2 Commercial insulation recommendations
Recommended minimum levels of slab insulation are given in Table 1-3 based on a location’s climate
zone, which can be found in Figure 1-5
Application
Slab with Ground Contact, Perimeter
Insulation by Climate Zone
Suspended Slab (e.g. between floors)
Horizontal Insulation
Heating Only
CZ 1-2: R-7.5, 12-inch depth
CZ 3: R-10, 24-inch depth
CZ 4-5: R-15, 24-inch depth
CZ 6-8: R-20, 48-inch depth
R-value that is 5 times the value of the oor covering’s R-value.
See Table 3-3 for more detail on the back loss as a function of
insulation below the suspended slab.
Cooling Only
R-5 where chilled slab abuts
unconditioned space
Same as heating
Heating and
Cooling
Same as heating Same as heating
Table 1-3 Minimum recommended R-values for slab insulation of conditioned slabs. Perimeter insulation
may be applied on the interior or exterior of the foundation. Perimeter insulation should be applied
vertically or a combination of vertically and horizontally, when it extends to at least the depth of the slab.
Listed depths are measured from the top of the slab.
Figure 1-10 Insulation detail for basement slab in Climate Zone 5
Concrete Slab
Foam Board Insulation:
24" min. height, 3" min.
thickness R-15
Sill Plate
Compact Subgrade
Gravel
ViegaPEX Tubing:
Minimum ¾" height of thin-slab
over PEX Tubing
Foundation Wall
Polyethylene Film:
6 mil (min.)
R-5 Insulation:
Refer to local code for insulation
requirements. (Ensure compression rating is
suitable for application.)
4"
45°