Is fiberglass insulation dangerous?

Is fiberglass insulation dangerous?

Fiberglass insulation or glass wool is a man-made vitreous fiber. ... If the insulation is not properly sealed off it can get into air vents and circulate through the building. Fiberglass insulation is not generally considered to be dangerous, but it can irritate the skin and respiratory system.

Is fiberglass a good insulation?

Fiberglass is a composite material made of a plastic matrix reinforced by tiny glass fibers. It is lightweight yet strong, and since glass isn't a good conductor of heat, it's a very effective insulation material.

How bad is breathing in fiberglass insulation?

Short-term Exposure Direct contact with fiberglass or breathing airborne dust containing fiberglass may irritate the skin, eyes, nose, and throat. The symptoms of irritation are often nonspecific, temporary, and may include itching, coughing, or wheezing.

Is Fiberglass still used in insulation?

Fiberglass is a type of fiber primarily composed of glass that is used in a wide variety of applications, and is predominantly employed as a residential and commercial thermal insulator. ... Fiberglass is an attractive choice for home insulation because it poses no fire hazard.

Why is Fibreglass used for insulation?

Due to the way fibreglass insulation is structured, it has many air pockets and these maintain its shape in the long term. It is a great option for blown insulation, as it offers a more consistent layer due to the way it settles, with plenty of air pockets.

What is the best insulation for attics?

Fiberglass, cotton, and mineral wool can all work as loose-fill material, but the far and away top choice for blown-in insulation is fiberglass. Contrary to batts, blown-in fiberglass insulation is perfect for filling in tight voids around wiring, pipes, or any area with awkward framing.

How many inches of insulation should be in my attic?

The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.

Can you have too much insulation in your attic?

But there may be a theoretical point of “too much.” If a home is over-insulated and is too tightly sealed, moisture can get trapped inside. Without proper ventilation, a home can build up too much moisture, especially in the attic (warm air rises), which can cause mold problems and, overall, lower indoor air quality.

Can you put 2 layers of insulation?

A: There's no problem with installing fiberglass batts over your existing blown-in insulation. ... If you install faced insulation over existing blown-in, you're essentially putting the vapor barrier in the middle, between the two layers of insulation.

Is it better to insulate attic ceiling or floor?

1 Answer. Since the ceiling in the attic is too low to make it into a living space, you should only insulate the floor. Insulating the ceiling will create a new heating zone, and essentially you will be paying more to heat your attic. ... When you are done, you should have a "carpet" of insulation on the floor.

Can I insulate the underside of my roof?

Just packing R-30 insulation against the underside of your roof deck will insulate it but do nothing to dissipate the inevitable moisture that will be trapped within the insulation. ... Not so with your insulated and sealed off ceiling/roof structure.

How do you tell if attic is properly vented?

How to determine whether you need better attic ventilation

  1. Look at your eaves and roof. ...
  2. Touch your ceiling on a warm, sunny day. ...
  3. Thick ridges of ice on your eaves in winter are a sign of poor attic ventilation. ...
  4. Warm air that escapes living space also carries moisture that will condense on rafters or roof sheathing.

Should I remove old attic insulation before adding new?

According to ENERGY STAR®, you can put new insulation over old insulation, “unless it is wet. ... “Faced” insulation should not be placed on top of existing insulation in the attic. Any new roll or batt insulation installed over existing insulation in the attic needs to be without a vapor retarder (face).

Should you insulate between roof rafters?

Remember, insulating between the joists will create a cold roof space, so if you're keeping anything up there that needs to stay warm, it's better to insulate between the rafters rather than the joists.

What is the most effective roof insulation?

Sheet Insulation Firm boards of either synthetic or natural materials, this is the best solution for insulating the underside of your roof. The boards provide highly effective insulation for your loft space and can also be decorated over. The downside is that sheet insulation tends to be the most expensive type.

Do you need an air gap for insulation?

Solid walls, however, must be faced with an insulation product, so they can often eat into floor space depending on the thickness of the insulation as an air gap is needed to prevent condensation and moisture build-up. Insulation with a moisture barrier means you don't need to leave an air gap during installation.

What's the best roof insulation?

Batts or blanket insulation are the best choice for ceiling insulation if you have a flat ceiling and pitched metal or tile roof. The range of batts and blankets that may be suitable for ceiling insulation include; polyester, natural wool, glass wool and rockwool.

What is the best internal wall insulation?

How to Choose the Right Type of Insulation

  • Rigid foam boards Rigid foam boards of insulation (such as Kingspan or Celotex) are better insulators than the alternatives and so they are thinner and take up less floor area. ...
  • Mineral wools Mineral wools such as Rockwool or Knauf are widely used.

What is the best exterior wall insulation?

What Is the Best Exterior Wall Insulation?

  • Blown-in fiberglassFiberglass is cost-effective and easy to install, though it does require some retrofitting for installation. ...
  • Wet-spray cellulose insulation – Blown-in spray cellulose is made up of a combination of recycled materials and flame-resistant chemicals.

Can you use r19 insulation in 2x4 walls?

Use R-19 or R-21 kraft-faced fiberglass insulation for two-by-six (2x6) walls. This combination ensures that the insulation is neither too loose nor too tightly packed within the walls. Two-by-four (2x4) stud walls with true 4-inch depth.

Can you add insulation when replacing siding?

By adding a continuous layer of insulation under new siding, you are able to wrap the home in a complete blanket of energy savings. In addition, flat foam insulations can help level out inconsistencies in the wall for a more perfect siding appearance.

What are the 3 types of insulation?

The most common insulation materials are fiberglass, cellulose and foam. Home insulation types include any of the above materials in the form of loose-fill, batts, rolls, foam board, spray foam and radiant barriers.

How long does Fiberglass Insulation last?

80 to 100 years

What is the best insulation to keep ice from melting?


What are the disadvantages of spray foam insulation?


  • The upfront cost is higher than conventional insulation.
  • Payback period is 2-4 years.
  • It is not generally a Do-it-Yourself project.
  • The installation process is longer.
  • The process could be messier.