Types of Insulation and Their Respective R Values
R value is an important part of all the insulation materials. The R value is usually expressed in terms of the thickness of the materials. Each insulation material has it advantages and disadvantages and is best used in certain areas of the house. For example, the foam insulation is generally used to fill tight spaces where other insulation materials are difficult to be applied.
The following paragraphs will explain in details the popular insulation materials and their respective R values.
Concrete Insulation
Recently the heat-treated concrete insulating blocks have become a highly popular insulating material for most of the building projects. The high demand for the concrete insulation is due to the high R value offered by the block. The concrete block not only acts as an extremely good insulator but is also highly durable and strong.
The concrete block mostly consists of polystyrene or polyurethane foam which give relatively high R value. In terms of R value, the concrete alone offers an R value of one point per inch thickness while the polystyrene gives 2 units of R-value per inch thickness.
The high efficiency of the concrete block is due to its interior which makes up as much as 80% of air. Moreover, air is difficult to flow between blocks due to the fact that these blocks are joined with mortar.
Expanding Foam Insulation
Expanding foam or spray foam insulation is a highly popular insulating material used in most households. This type of insulation is extremely efficient and easy to use as it’s meant for tight spaces where other insulation materials cannot be applied. Spray foam insulation can fill the smallest spaces in your house and is highly suitable for areas with lots of nooks and crannies.
The material makes up the foam can be from a lot of materials but the most popular material is phenolic or polyurethane. Foam insulation offers high R value and it can provide as much as 6 units to sometimes even 8 units per inch.
The downside to spray foam insulation is that it’s relatively expensive and special tools are needed to inject the foam.
Fiberglass Insulation
Fiberglass insulation is another popular insulation material due to fact that it’s low cost and is easy to carry and install. It usually comes in rolls and has a variety of sizes, normally 16 to 24 inches wide. Fiberglass insulation is generally used to fit between the studs of exterior walls.
Rolls fiberglass insulation is the most used insulation material in the US and they are made from strings of material that are bound together which makes the rolls fiberglass extremely strong and long lasting.
Besides, the R value of rolls fiberglass or batt insulation sits between 3 to 6 units per inch. To prevent moisture from seeping into the fiberglass rolls or batts, the fiberglass is usually covered with sheets to keep the moisture out. As a result, fiberglass rolls usually come with two forms, faced and unfaced. The faced fiberglass is the recommended one you should be using.
Rigid Foam Insulation
Rigid foam insulation is used heavily in most domestic houses especially when insulating the roof, floor, walls and the basement. Rigid foam insulation is made from polystyrene and is molded into durable and hard board that resembles sheets of plywood. They come in a variety of thickness which provides a range of R values that come from 4 to 5 per inch.
Rigid foam insulation boards are highly durable and they are usually coated with a vapor barrier to keep moisture out. These boards are relatively cheap and easy to maintain. They can be easily installed on your own to save installation cost.
Foil Insulation
Foil insulation is getting very popular in recent years due to its lightweight features and they are easily cut and installed on your own. Foil insulation is also referred to as reflective insulation and they are extremely useful against radiant heat. You can find foil insulation being used to cover the front of most foam insulation panels.
The advantage of foil insulation is its lightweight features and durability. It offers relatively high R value, usually in the range of 3 to 6 based on its material coating. The disadvantage to foil insulation is that it conducts electricity easily. As a result, foil insulation is usually kept away from wires and anything that conducts electricity.
