Insulation

There are many different insulation types with varying properties including their ability to insulate. Some are more desirable than others based on the application they are used in.

What’s an R-Value? — this is the unit used to describe thermal resistance. You may have heard of RSI values too. RSI is the metric equivalent of R-values.  

There are five broad categories insulation can fall into:

1. Rigid Insulation
2. Spray Foam Insulation
3. Sprayed In Place Insulation
4. Batt Insulation
5. Loose Fill Insulation

Below is a summary of some of these more common types.

1.0    Rigid Insulation

1.1 Fibreglass (Above Grade) is designed to be used as an exterior sheathing. It is faced on one side with an air / moisture barrier to prevent water and air infiltration from lowering its R-value. R-value is 4.4 per inch (RSI 0.031/mm).

Pros — Does not support combustion well; can achieve higher R-value on exterior walls

Cons — No major disadvantages known

1.2 Fibreglass (Below Grade) is an un-faced product with a higher density than its above grade version. Designed to act as a drainage layer between the foundation wall and surrounding soil. R-value is 4.2 per inch (RSI 0.029/mm).

Pros — Does not support combustion well; can provide drainage next to a foundation wall

Cons — Can not sit in water; good drainage system required

1.3 Expanded Polystyrene is made by expanding polystyrene beads. From here it is then bonded together to form rigid boards. It comes in two densities

(1) High density board is more moisture resistant and can be used on the exterior of a foundation providing good soil and drainage conditions are present. R-value is 4.0 per inch (RSI 0.028/mm).

(2) Low density is designed for above grade applications. R-value is 3.7 per inch (RSI 0.026/mm).

Pros — Designed for interior or exterior applications where space is limited; light weight; less costly than most rigid insulations; not a skin irritant

Cons — UV (ultra violet) light degradation can occur if not protected from sunlight; must be protected from solvents and non-compatible sealants; interior applications require that it be covered with an appropriate fire rated material; low density board designed for above grade applications only

1.4 Extruded Polystyrene is a “closed cell” foam plastic board, which is made in a high and low density board version suitable for below grade applications. Low density: R-value is 4.7 per inch (RSI 0.033/mm). High density: R-value is 5.0 per inch (RSI 0.035/mm).

Pros — Designed for interior or exterior applications where space is limited; lightweight; high-density version handles relatively high pressures under concrete slabs, etc.; not a skin irritant; when joints are sealed it acts as an air barrier

Cons — UV (ultra violet) light degradation can occur if not protected from sunlight; must be protected from solvents and non-compatible sealants; interior applications require that it be covered with an appropriate fire rated material

1.5 Polyurethane & Polyisocyanurate insulations are created by the chemical reactions between poly-alcohols and isocyanurates. They are “closed cell” insulation boards. These cells contain refrigerant gases (fluorocarbons) instead of air. The boards are usually double-faced with foil, or sometimes come bonded with an interior or exterior finishing material.

Faced boards: typical R-value is 5.8 per inch (RSI 0.040) to 7.2 per inch (RSI 0.050).

Pros — Designed for interior or exterior applications where space is limited; when joints are sealed it acts as an air barrier; very high R-value per inch

Cons — UV (ultra violet) light degradation can occur if not protected from sunlight; must be protected from prolonged exposure to water / moisture; interior applications require that it be covered with an appropriate fire rated material; very expensive compared to other types of insulation

1.6 Phenolic Foam is made from phenol formaldehyde resin, and is available in open or closed cell versions. The boards usually come with a foil facing on one or both sides.
Open cell: R-value is 4.2 per inch (RSI 0.029). Closed cell: R-value of 8.3 per inch (RSI 0.058).

Pros — Designed for interior or exterior applications where space is limited; very high R-value per inch; less combustible than other rigid insulation

Cons — UV (ultra violet) light degradation can occur if not protected from sunlight; must be protected from prolonged exposure to water / moisture; most expensive rigid insulation; interior applications require that it be covered with an appropriate fire rated material

2.0 Spray Foam Insulations

2.1 Polyurethane Foam is a closed cell foam that is often pale yellow in colour used for in a wide number of spray applications. In large applications it is made on site with specialized equipment. For small single purpose uses spray cans are available. R-value is 6.0 per inch (RSI 0.042/mm).

Pros — Protects against air infiltration; fills irregular and narrow openings

Cons — Interior applications require that it be covered with an appropriate fire rated material; specialized equipment and experienced contractors required for large projects; UV (ultra violet) light degradation can occur if not protected from sunlight

2.2 Isocyanurate Plastic Foam is a two-component material, and is made from a combination of isocyanurate, resins and catalysts. It creates an open celled plastic foam insulation that is pliable. R-value is 4.3 per inch (RSI 0.030/mm).

Pros — Protects against air infiltration; fills irregular and narrow openings

Cons — Interior applications require that it be covered with an appropriate fire rated material; specialized equipment and experienced contractors required; restrictions on the thickness of the applied material

3.0 Sprayed-In-Place Insulations are loose fill products that are blown into wall cavities. During the blow-in stage the insulation is mixed with an adhesive, usually water-based, that binds the product together making a seamless batt.

3.1 Cellulose sprayed in -place has the same properties as loose fill insulation except an adhesive is added in the process to make it stick to the surface it is applied to. R-value is 3.5 per inch (RSI 0.024/mm).

Pros — Resistant to settling; resistant to air infiltration; wall cavities can be completely filled

Cons — Specialized equipment and experienced contractors required

3.2 Fibreglass that is blown in is made from the same product as fibreglass batts except that it’s chopped up and an adhesive is added in the process to make it stick to the surface it is applied to. R-value is 2.9 per inch (RSI 0.02/mm).

Pros — Resistant to settling; wall cavities can be completely filled; R-value not affected if a bit of moisture is present

Cons — Eye, skin and respiratory irritant during installation; specialized equipment and experienced contractors required

3.3 Mineral Wool (Slag and Rock Wool) is the same product as its loose fill version batts except that it’s chopped up and an adhesive is added in the process to make it stick to the surface it is applied to. Slag and rock wool: R-value is 3 per inch (RSI 0.021).

Pros — Resistant to settling; wall cavities can be completely filled; doesn’t support combustion; R-value not affected if a bit of moisture is present

Cons — Eye, skin and respiratory irritant during installation; specialized equipment and experienced contractors required

4.0 Batt Insulation is a very common form of insulation still in use today.

4.1 Fibreglass batts as its name implies are made from glass that has been spun into fibres. It is then woven and coated with a binding agent. Average R-value is 3.2 per inch (RSI 0.022/mm).

Pros — Fits standard joist & stud openings; easy to install; resistant to fire & mould; R-value not affected if a bit of moisture is present

Cons — Eye, skin and respiratory irritant during installation; doesn’t easily fit into irregular spaces; R-vale can reduce if there is air movement present; heavier materials or insulation installed over it may compress it

4.2 Mineral Wool (Slag and Rock Wool) is manufactured from molten industrial slag that is then made into a fibre and treated so it suppresses dust and maintains its shape. Similar in looks to fibreglass with regard to texture and appearance. Rock Wool is made in a similar manner but natural rock is used instead of slag. Slag & Rock Wool: Average R-value is 3.3 per inch (RSI 0.023).

Pros –Fits standard joist & stud openings; easy to install; insulation good around chimneys as it doesn’t support combustion; R-value not affected if a bit of moisture is present

Cons — Eye, skin and respiratory irritant during installation; doesn’t easily fit into irregular spaces; R-value can reduce if there is air movement present; heavier materials or insulation installed over it may compress it

5.0 Loose Fill Insulation is likely the most common form of insulation used today.

5.1 Cellulose Fibre insulation is made from finely shredded newspaper. It is then is chemically treated to resist fire and mould growth.

Blown Cellulose: Average R-value is 3.6 per inch (RSI 0.025/mm). This is dependant on the chemical mix, paper type and density it is blown in at. Blown cellulose can be installed in vertical wall cavities using a variety of specially designed, reinforced interior sheeting products.

Poured Cellulose: Average R-value is 3.4 per inch (RSI 0.024/mm).

Pros — Fills irregular horizontal spaces; blown-In cellulose can be installed with rented equipment or hand poured; chemical additives provide resistance to fire, corrosion, vermin and mould; R-value not affected if a bit of moisture is present

Cons — Heavier materials or insulation installed over it may compress it; product settles over time; must install to manufacturer’s specifications in order to achieve desired R-value

5.2 Fibreglass

Blown Fibreglass is largely no different than fibreglass batts, except that the material is ‘chopped up’. R-value is 2.9 per inch (RSI 0.02/mm).

Poured Fibreglass has basically the same properties as the blown product. R-value is R-3 per inch (RSI 0.021/mm).

Pros — Fills irregular horizontal spaces; resistant to fire & and mould; R-value not affected if a bit of moisture is present

Cons — Eye, skin and respiratory irritant during installation; heavier materials or insulation installed over it may compress it

5.3 Mineral Wool (Slag and Rock Wool) The loose fill version of this product has the same properties as its batt insulation.

Blown Mineral Wool: R-value of 2.7 per inch (RSI 0.019
Poured Mineral Wool has basically the properties as the blown product. R-value is R-3.0 per inch (RSI 0.021).

Pros — Insulation good around chimneys as it doesn’t support combustion; R-value not affected if a bit of moisture is present; fills irregular horizontal spaces

Cons — Eye, skin and respiratory irritant during installation; heavier materials or insulation installed over it may compress it

5.4 Vermiculite is a mineral product that when heated expands to form a lightweight insulating material. There are two types of vermiculite:

Treated vermiculite: coated with asphalt to make it water-resistant. Average R-value is 2.5 per inch (RSI 0.017/mm)

Untreated vermiculite — absorbs water. Average R-value is 2.3 per inch (RSI 0.016/mm).

Pros — Pours easily into irregular spaces; not combustible; non-abrasive, odourless and non-irritating

Cons — Dries very slowly after becoming wet; typically not used in high R-value applications

5.5 Wood Shavings were often treated with lime or other chemicals to increase their resistance to water / moisture, fire and mould growth.

Average R-value is 2.44 per inch (RSI 0.0169/mm).

Pros — Readily available & inexpensive

Cons — Low R-value; dries very slowly after becoming wet; difficult to treat against fire, vermin and mould growth; can settle over time.