How to Inspect Your Homes Insulation

Inspecting Your Attic

You will have to access your attic through an attic hatch or possibly a garage entrance opening.  Tools and Safety equipment should consist of Hard Hat,  Flashlight, Tape Measure, Safety Glasses and Dust Mask.  When opening Vermiculite-Insulationyour attic hatch try not to damage your hatch seal which prevents air from entering attic area.  If you find Vermiculite Insulation do not enter attic area until you have it tested by an approved laboratory for Asbestos.

While still at the attic entrance area you should check under any existing insulation to ensure that there is no vermiculite present prior to entering the attic area.  As a home inspector we are not required to enter the attic areas if floor joists are not visible.  Unless there is some visible defects with existing insulation it is better not to walk through attic area unless boards have been previously installed, there is always the danger of putting foot through the homes drywall or plaster ceiling.

Another hazard you may encounter in an attic is electrical wiring.  Century style homes may still have knob and tube wiring which can shock you if you come in contact with it.  Modern homes are required to have electrical wiring in attic supported on boards when there is a minimum of 1 meter clearance above the cables.  Another item to look at when up in the attic area is the condition of the visible electrical wiring, mice or other rodents have been known to gnaw on the electrical insulation which if extensive will most likely require new wiring to be installed to replaced damaged cables.  Read more about Insulation Defects

Types of Insulation

Fiberglass Insulation

The most common type of insulation found in attics in Barrie On is blown fiberglass insulation.  Blown fiberglass has the benefits of being fast and easy to install and it fills any gaps or cracks even in awkward places. Fiberglass batts are sometimes used in attics but are more common in wall installations and floors in un-enclosed spaces.  The only downside to installing blown fiberglass insulation is the fact that mice just love to nest in it.  Roughly around 95% of attics I inspect that have fiberglass insulation also have a multitude of mouse holes and trails throughout the attic area.  You can have your home mouse and rodent proofed for around $1,000.00 depending on size.  They will caulk around your soffits, put protective screens on all your exterior openings and install two or more one-way exits for the mice to exit by.   Mice apparently have to leave your attic to find water so it is a one-way trip once your home is mouse proofed.

Fiberglass batts were popular until the late 80’s and early 90’s.  While blowing insulation into attic only takes a couple of hours, installing fiberglass batts can take a couple of days.  There is also a lot of seams that can allow passage of air and heat, which can be partly remedied by installing two layers of insulation in different directions.  Fiberglass batts are still the most popular product for insulating walls in homes.  Mice also love nesting in attics with fiberglass batts installed.  A nice warm attic in winter is just like going to Florida for mice.

Some of the Advantages of Fiberglass Batt Installation:

  • Moisture Resistance – Though fiberglass isn’t impervious to water, it does tend to resist moisture effectively. This makes it less vulnerable to the growth of mold and mildew.
  • Fire Resistance – Fiberglass is noncombustible, so you can rest easy if you have to install it next to your attic’s wooden structure.
  • Easy Installation – Batts are easy to pick up and unfurl. And due to their size, they can cover a lot of real estate in a pinch. This makes them a prime candidate for new construction as long as they are installed properly.

Cellulose Insulation

Cellulose insulation is by far my favourite blown insulation for attics.  Cellulose insulation mainly consists of recycled newspaper type material which is treated with fire-retardant.  The mice apparently don’t like the fire-retardant material and very rarely will you find evidence of mice in an attic filled with cellulose insulation.  When explaining this to my clients I often refer to a an attic filled with cellulose looking like a desert scene as the insulation is undisturbed and no mouse holes or trails are to be seen.

Safe and Sound Insulation

Roxul Safe’n’Sound™ is a semi-rigid batt insulation designed specifically for interior wall and floor/ ceiling applications. This stone wool-based* insulation is made from natural stone and recycled content. It’s a green product that provides superior sound absorbency and fire protection for overall comfort and safety. It’s not thermal insulation. Roxul Safe’n’Sound is designed specifically for one purpose – soundproofing. It is not intended for thermal applications like insulating exterior walls or attics. The optimized density that makes it an ideal sound barrier actually compromises its ability to prevent heat loss.  Many municipalities in Ontario now require Safe and Sound insulation to be installed in fire separation ceilings in converted basement legal apartments.

Rockwool Insulationrockwool insulation

The process by which Rockwool insulation is made helps to explain the true fire-resistant potential of this product. It’s composed primarily of basalt rock and a recycled steel-making byproduct known as slag. These components are superheated, allowing them to liquefy and mix together into a lava-like liquid. In order to melt these substances, the temperatures must exceed 2,900 degrees Fahrenheit.  The mixture is then blown into a large spinning chamber designed to stretch the superheated liquid into fibers. These fibers are then gathered together and compressed into a mat, which can be cut into slabs of Rockwool insulation.   While fiberglass insulation is capable of offering an R-value of about 2.2 to 2.7 per inch of insulation, Rockwool has an R-value between 3.0 to 3.3 per inch of insulation, and its almost complete lack of organic materials make it highly resistive to mould and mildew.

Spray Foam Insulation

Spray foam has become very popular for use in crawl spaces, rim joist insulation, exterior wall insulation and floors of rooms above un-heated garages.  Spray foam is either “open cell” or “closed cell”,  knowing the difference is important depending on the results you are looking for.

With open-cell foam, the tiny cells of the foam are not entirely closed, so the foam itself is porous and can fill with air and moisture. These tiny open spaces render the foam weaker and softer than closed-cell foam. Unlike open-cell spray foam, closed-cell foam has all the tiny cells of the foam sealed. The cells possess a gas that provides the spray foam with the capability to expand and better insulate a structure. During the formulation process, the cells are developed to have certain characteristics.

Open-cell spray polyurethane foam, sometimes called half-pound foam, has a typical density of 0.5 lb. per cubic foot and a typical R-value of 3.5 or 3.6 per inch.

Closed-cell foam, also called two-pound foam, has a typical density of 2 lbs. per cft and an R-value of 6-6.5 per inch.

Open-cell spray foam has an average density of 0.5 lbs per cubic foot. It delivers a typical R-Value of 3.5 to 3.6 per inch. Since the open cells are somewhat vapor-permeable, three inches of open-cell foam have a permeance of 16 perms. It often requires a vapor retarder when utilized in internal applications.

Closed-cell foam is itself a vapor retarder. It is vapor semi-impermeable. Two and a half inches of closed-cell foam have a permeance of 0.8 perms.

High Density Spray Foam

High-density spray foam insulation is used when an extremely high R-value and extra strength is needed. Typically, high-density spray foam insulation is often employed for exterior and roofing applications in commercial or industrial construction.

Medium Density Spray Foam

Medium-density spray foam insulation requires around 2 lbs. of closed-cell spray foam per cubic foot. It has a high R-value, which starts at 5.7 per inch.

Low Density Spray Foam

Also known as open-cell foam or half-pound foam, low-density spray foam insulation utilizes around 0.5 lbs. of open-cell foam per cubic foot. This insulation material is full of cells that are purposefully left open, making the foam softer, less dense, and more flexible.

Note: Polyurethane Foam is listed as combustible insulation.  A thermal barrier is required over all exposed foam insulation except in attic or crawlspace.

Canadian homes must be able to withstand long harsh winters, meaning heating a home is a major financial expense. Over 60% of home energy consumption in Canada is used to heat homes. Proper insulation will reduce your energy consumption, saving both money and greenhouse gas emissions.