Covering

Advantages

Disadvantages

Light Transmission

"U" Factor

Insulating Value "R"

Estimated Lifetime

Cost per Sq./Ft.**

Single Layer Polyethylene Film

Inexpensive

Easy to install

Short life

85 %

1.2

.83

1 to 4 years

$.10

Double Layer Polyethylene Film

Inexpensive

Saves on heating costs

Easy to install

Short life

77%

.70

1.43

1 to 4 years

$.19

Clear

Corrugated Polycarbonate

High transmittance

High impact resistance

Scratches easily

91%

1.2

.83

15 plus years

10 year warranty

$1.37

Opal or Gray

Corrugated Polycarbonate

High transmittance

High impact resistance

Scratches easily

80% and 35%, respectively

1.2

.83

15 plus years

10 year warranty

$1.48

Glass Double Strength

High light transmittance

High UV resistance

Resists scratching

High cost

Difficult installation

Low impact resistance

High maintenance

88%

1.1

.91

25 plus years

$2.00

Glass Insulated

High light transmittance

High UV resistance

Resists scratching

Very high cost

Difficult installation

Low impact resistance

78%

.70

1.43

25 plus years

$5.00

3.5mm

Twin Wall Solexx Polyethylene

Diffuses intense sunlight

More flexible than polycarbonate

Easy to cut

Comes only in translucent white

Less rigid than polycarbonate

70-77%

.48

2.10

15 plus years

8 year warranty

$1.27

5mm

Twin Wall Solexx Polyethylene

Diffuses intense sunlight

More flexible than polycarbonate

Easy to cut

Comes only in translucent white

Less rigid than polycarbonate

70-75%

.43

2.30

15 plus years

8 year warranty

$1.59

Clear

4mm Twin Wall Polycarbonate

High impact resistance

Saves on heating costs

Requires glazing system to install Scratches easily

82%

.70

1.43

15 plus years

10 year warranty

$1.50

Clear

6mm Twin Wall Polycarbonate

High impact resistance

Saves on heating costs

Requires glazing system to install Scratches easily

82%

.65

1.54

15 plus years

10 year warranty

$1.63

Opal or Bronze

6mm Twin Wall Polycarbonate

High impact resistance

Saves on heating costs

Requires glazing system to install Scratches easily

82%

.65

1.54

15 plus years

10 year warranty

$1.80

Clear

8mm Twin Wall Polycarbonate

High impact resistance

Saves on heating costs

Requires glazing system to install Scratches easily

82%

.62

1.61

15 plus years

10 year warranty

$1.74

Opal or Bronze

8mm Twin Wall Polycarbonate

High impact resistance

Saves on heating costs

Requires glazing system to install Scratches easily

82%

.62

1.61

15 plus years

10 year warranty

$1.89

Clear

16 mm Triple Wall Polycarbonate

High impact resistance

Saves on heating costs

Requires glazing system to install Scratches easily

81%

.42

2.38

15 plus years

10 year warranty

$4.17

Opal or Bronze

16 mm Triple Wall Polycarbonate

High impact resistance

Saves on heating costs

Requires glazing system to install Scratches easily

81%

.42

2.38

15 plus years

10 year warranty

$4.75