There’s no doubt that insulation is perhaps the single most important product that will determine the energy costs of your residence. Therefore it’s extremely important to determine the right type of insulation to use. There are many types of insulation in the market that can be very easily obtained. Each type has its advantages and disadvantages. Before selecting one type over the other, you should take into consideration where you want to install it (exterior or interior space), what is the intended use (thermal, fire, and/or moisture resistance, sound reduction or absorption), what ‘R’ (thermal resistance value) you need, and ease of access to the place intended for its use. Don’t forget, the higher the ‘R’ value, the better thermal resistance.

Local building codes establish the minimum required thickness for different locations. For example, in NYC exterior walls are required to have a thermal value of R-19 for exterior walls, and R-30 for the roof.


Below is a list of the most popular types of insulation available:


1-     FIBERGLASS: It’s the most commonly used type of insulation. It consists of small diameter pink, yellow, or white glass fibers, formed into blankets or batts. It comes in rolls of different widths ready to be placed in between studs (16” and 24” most common), and thicknesses (which determine the R-thermal resistance- value). This type of insulation is ready to be applied on exterior and/or interior walls, roof, floors, or in between floors. One side may have a foil backing that should face the warm side of the space when installed.


-  Very economical.

-  Easy to install.                                                                                                                                                              $

-  Can handle small amounts of moisture.

-  Non flammable.

-  Good for sound attenuation between spaces.

-  Should be installed with protective gear (gloves, goggles, mask, etc) to prevent an itchy aftermath.

-  Usually 6” thick for exterior walls (R-19), 10” for roofs (R-30). Check your local codes for required “R value”.




2-     LOOSE FILL or BLOWN INSULATION:  Most economical type of insulation.  It’s made out of Cellulose, recycled paper, or newsprint. It has a high content of recycled material. Good for irregular or hard to reach spaces. Typically used in wall cavities, or on unfinished attic floors.



-  Not very air tight. Air can flow through the insulation.

-  Not good for sound absorption.

-  Doesn’t offer fire resistance.                                                                                                                                        $

-  Requires professional installation.

-  Good nesting material for rodents.

-  Permanently damaged if wet.

-  Can cause poor indoor quality conditions.


3-     MINERAL WOOL or ROCK WOOL:  more expensive than fiberglass.It comes in rolls as the previous type, and in blankets. It’s easy to handle and install. It’s made from inorganic fibers obtained from volcanic rocks. Not easy to find as fiberglass.


-  Better thermal insulation

-   Good for sound isolation and absorption.

-  High fire resistance.                                                                                                                                                     $$

-  Lower moisture absorption.

-  Doesn’t provoke itching sensation while installing.

-  Can retain moisture, and prone to get mold if left wet.





4-     RIGID BOARD INSULATION:  Insulation made of fiberglass, polystyrene, polyurethane, or other materials sold in the form of lightweight panels or boards. They come in different types, where Polyisocyanurate (ISO) is the best of this kind. Foil-faced ISO panels are considered impermeable, and are used as exterior wall insulating sheathing.


-  High R value, which diminishes over time.

-  Expensive.

-  Stops moisture.

-  Tongue and groove panel connection.                                                                                                                           $$

-  Easy to apply.

-  May require professional installation.

-  Can be used for foundation insulation, and under concrete slabs.

-  Not environmentally friendly.



5-     SPRAY APLIED FOAM INSULATION:  is a quick expanding type of spray foam. Primarily used for remodel jobs where there are existing walls with drywall already in place. This plastic insulation goes on as a liquid and expands to fill the available space, sealing all gaps and cracks and stopping any air leaks.
It can be “open cell”, where spaces between the cell are not completely closed, or “closed cell”, where’s there’s no space in between cells.


-  “Open cell” works well for air barrier and for sound reduction

     in interior spaces. It allows water vapor to pass through.

High R value.

-  More economical than “close cell”.                                                                                                $$$    

-  Excess spraying needs to be cut away.          

-  Requires professional installation.

-  Releases chemicals and VOC’s when applied.




“Closed cell” with vapor barrier is suitable for exterior walls & roof.

High R value.

-  Excess spraying needs to be cut away.          

-  Requires professional installation.                                                                                                 $$$$

-  Releases chemicals and VOC’s when applied.

-  Relative expensive.



When renovating homes that were built prior to the 1980’s, chances are that you’ll find asbestos insulation in them. It’ is then recommended to have the house inspected by a qualified asbestos professional prior to engaging in any kind disturbance to the existing conditions. Any asbestos containing material that can be found during a work site survey must be removed by workers who are trained in asbestos removal and wear protective clothing and a respirator. Unless you are properly trained, do not try to remove asbestos yourself. Any asbestos containing material found must be removed by workers who are trained in asbestos removal and wear protective clothing and a respirator. Unless you are properly trained, do not try to remove asbestos yourself.

A house that is well designed, and that has the right type of insulation properly installed, reduces the energy bills, therefore making it much more attractive for potential buyers. There are in the market some “green” insulation products made out of recycled cotton or paper, which are not as effective as the more traditional types. However, the use of any type of insulation described above reduces the need of energy required to heat or cool your place, making it then a green solution.