Uninsulated U-Value
Perimiter / Area Ratio
P/A=
0.10
0.1253
0.13
0.14
0.15
0.16
0.17
0.18
0.19
0.20
0.30
0.40
0.50
0.60
0.70
Uninsulated U-Value
Uo=
0.21
0.25
0.26
0.27
0.29
0.3
0.32
0.35
0.36
0.36
0.50
0.62
0.73
0.83
0.92
Thermal Res Unins
R=
4.76
4.00
3.84
3.7
3.44
3.33
3.12
3.03
2.85
2.77
2.00
1.61
1.36
1.20
1.08
Additional Res Required
R+
n/a
0.00
0.16
0.3
0.56
0.67
0.88
0.97
1.15
1.23
2.00
2.39
2.64
2.80
2.92
EXPANDED POLYSYTRENE (SDN) (Jablite etc) Thickness Required Assuming K=0.037 W/mk
Insulation reqd (mm)
ITR=
n/a
0
6
12
21
25
33
36
43
46
74
89
98
104
109
EXPANDED POLYSTYRENE (HDN) (Jablite etc) Thickness Required Assuming K=0.035 W/mk
Insulation reqd (mm)
ITR=
n/a
0
6
11
20
24
31
34
41
44
70
84
93
98
103
EXPANDED POLYSTYRENE (EHDN) (Jablite etc) Thickness Required Assuming K=0.033 W/mk
Insulation reqd (mm)
ITR=
n/a
0
6
10
19
23
30
33
38
41
66
79
88
93
97
EXTRUDED POLYSTYRENE (Polyfoam etc) Thickness Required Assuming K=0.028 W/mk
Insulation reqd (mm)
ITR=
n/a
0
5
9
16
19
25
28
33
35
56
67
74
79
82
EXTRUDED POLYSTYRENE Thickness Required Assuming K=0.026 W/mk
Insulation reqd (mm)
ITR=
n/a
0
5
8
15
18
23
26
30
32
52
63
69
73
76
PolyurethaneThickness Required Assuming K=0.022 W/mk (Kingspan)
Insulation reqd (mm)
ITR=
n/a
0
4
7
13
15
20
22
26
28
44
53
59
62
65
PolyurethaneThickness Required Assuming K=0.019 W/mk (Celotex RR, Ecotherm, Floortherm etc)
Insulation reqd (mm)
ITR=
n/a
0
4
6
11
13
17
19
22
24
38
46
51
54
56
Click Here To Download- Floor Insulation Table

Warmafloor UK. Concorde House, Concorde Way, Segensworth North,

Fareham, Hampshire, PO15 5RL

TEL : 01489 581787 FAX: 01489 576444