Florida Commercial Roof Insulation Types

Florida Commercial Roof Insulation Types

By phogan October 5th, 2011

Exploring the elective components of a commercial roofing system in Florida, we now take a look at types of insulation.

Roof insulation performs two basic functions:

  • Acts as a thermal barrier for the top of the building.
  • Serves as the base for the roof sytem.

Secodary functions include:

  • Enhancing drainage through the use of tapered insulation systems and stiffened roof decks.

Poly-isocyanurate

Far and away the most common roof inulation installed, ISO is available in flat or tapered panels and is the base for many roof systems with an average LTTR value of 5.56 per 1 of product. Polyisocyanurate features a closed cell iso core integrally laminated to fiber reinforced felt factors. Iso has a perforated facer on one side for use with hot asphalt applied systems while the non-perforated side is for use with single-ply systems.

High R value of 5.5 per inch and good compressive strength. Excellent dimensional stability and very lightwwight.

Contains CFCs or HCFCs which may be released into the environment, causing ozone depletion. It is also expensive in comparason to other insulations. Contains a petroleum by-product increasingly in demand worldwide, resulting in availability problems and lengthy lead times for orders.

Perlite

Perlite insulation is an inorganic, rigid board insulation available in 2 x 4 or 4 x 4 panels. The panels are composed of expanded volcanic glass and wood fibers bonded with asphaltic binders. Until recently, perlite was the most common insulation used in roofing. Although still popular, its low R-value of 2.78 per inch and tendency to absorb moisture have diminished its frequency of use.

Perlite has an excellent fire protection resistance rating. It also has good compressive strength which allows normal roof foot traffic. It also has great dimentional stability and the ability to absorb outgassing common in foam and iso insulations. It is often used as a cover board in hot asphalt sytems.

Very friable and relatively easy to break panels. Complete deterioration when in contact with moisture. Low R value and poor tensile strength.

Expanded/Extruded Polystyrene

As the lead times required for isocyanurate insulation increases, EPS has risen as a low-cost alternative for roofing insulation. Both types are manufactured from polystyrene, one as a fused board made of beads while the second is formed from a molten sheet pressed into shape.

Wood Fiber

The final insulation we will examine is wood fiber. It is the oldest type designed for roofing. It is normally found in a high density form and is inexpensive and durable. It is also often used as a cover board over iso in hot applications to reduce outgrassing.

Each project and roof assembly has its own subtle differences that may lend itself to a particular size, type, or thickness of insulation. Additionally, the expense at insulation should be cost-factored in comparison to heating or cooling billd over the expected life of the assembly to determine the most effective insulation for a particular project. Your contractor, consultant, or manufacturer can all play vital roless in helping with the final decision based on R value needs, anticipated length of ownership, and local codes.

By phogan October 5th, 2011

Exploring the elective components of a commercial roofing system in Florida, we now take a look at types of insulation.

Roof insulation performs two basic functions:

  • Acts as a thermal barrier for the top of the building.
  • Serves as the base for the roof sytem.

Secodary functions include:

  • Enhancing drainage through the use of tapered insulation systems and stiffened roof decks.

Poly-isocyanurate

Far and away the most common roof inulation installed, ISO is available in flat or tapered panels and is the base for many roof systems with an average LTTR value of 5.56 per 1 of product. Polyisocyanurate features a closed cell iso core integrally laminated to fiber reinforced felt factors. Iso has a perforated facer on one side for use with hot asphalt applied systems while the non-perforated side is for use with single-ply systems.

High R value of 5.5 per inch and good compressive strength. Excellent dimensional stability and very lightwwight.

Contains CFCs or HCFCs which may be released into the environment, causing ozone depletion. It is also expensive in comparason to other insulations. Contains a petroleum by-product increasingly in demand worldwide, resulting in availability problems and lengthy lead times for orders.

Perlite

Perlite insulation is an inorganic, rigid board insulation available in 2 x 4 or 4 x 4 panels. The panels are composed of expanded volcanic glass and wood fibers bonded with asphaltic binders. Until recently, perlite was the most common insulation used in roofing. Although still popular, its low R-value of 2.78 per inch and tendency to absorb moisture have diminished its frequency of use.

Perlite has an excellent fire protection resistance rating. It also has good compressive strength which allows normal roof foot traffic. It also has great dimentional stability and the ability to absorb outgassing common in foam and iso insulations. It is often used as a cover board in hot asphalt sytems.

Very friable and relatively easy to break panels. Complete deterioration when in contact with moisture. Low R value and poor tensile strength.

Expanded/Extruded Polystyrene

As the lead times required for isocyanurate insulation increases, EPS has risen as a low-cost alternative for roofing insulation. Both types are manufactured from polystyrene, one as a fused board made of beads while the second is formed from a molten sheet pressed into shape.

Wood Fiber

The final insulation we will examine is wood fiber. It is the oldest type designed for roofing. It is normally found in a high density form and is inexpensive and durable. It is also often used as a cover board over iso in hot applications to reduce outgrassing.

Each project and roof assembly has its own subtle differences that may lend itself to a particular size, type, or thickness of insulation. Additionally, the expense at insulation should be cost-factored in comparison to heating or cooling billd over the expected life of the assembly to determine the most effective insulation for a particular project. Your contractor, consultant, or manufacturer can all play vital roless in helping with the final decision based on R value needs, anticipated length of ownership, and local codes.


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