Disadvantages of fiberglass insulation:
- Diminished R-value due to thermal bridging
- Does not stop radiant heat transfer (The primary source of heat flow in and out of your structure).
- Pinching or smashing reduces its R-value.
- Moisture reduces its R-value.
- Potential health risks such as lung damage
- Batts do not seal wall and ceiling cavities tightly
- Needs an additional vapor barrier to protect it from moisture
- Can settle resulting in declined effectiveness
- Moiture build-up between the fiberglass and the building exterior cannot evaporate, therefore causing mold, mildew and decay. Fiberglass insulation R-value is reduced by thermal bridging, pinching and moisture.
The actual R value of fiberglass insulation may be lower by as much as 20% due to wood framing. Wood framing that holds the insulation in place reduces its effectiveness. Wood conducts heat faster than insulation, a phenomenon known as "thermal bridging." Fiberglass sheets or "batts" in a 2-by-6 wall can be rated R-19 by its manufacturer, but the conductive effects of the wood framing would reduce this to R-15. Installing Prodex Total insulation over the studs rather than fiberglass between the studs solves the bridging dilemma.
Any pinching or smashing of fiberglass insulation also reduces its R-value. To be effective, fiberglass must be kept fluffy soft and not be exposed to high-moisture such as a damp basement where the material will be compacted if it gets wet, negating its insulation value"(Vaughn, 2007). Fiberglass insulation requires an additional vapor barrier (or vapor retarder) between the warm surface of the wall or ceiling and the insulation. Fiberglass insulation does not stop radiant heat transfer (The primary source of heat flow in and out of your structure). It does not adequately control air infiltration. Batts are particularly unpleasant to hang overhead in ceilings and under floors and they require straps or wire mesh across the joists to hold them up. Cutting the batts to accommodate electrical boxes, duct, wiring, plumbing and chimneys creates a free air path through the wall cavitity or attic floor. Prodex Total attached over the studs provides a tighter air barrier.
Protect yourself when installing fiberglass insulation. Warnings on the insulation rolls advise you to completely protect yourself from coming into any contact with fiberglass. You're advised to wear safety glasses with side shields, face mask or respirator, gloves, long tight sleeves, long pants and hat. Even after all these precautions, the itchy fibers manage to get in. In addition to physically protecting yourself from fibers during installation with safety gear, installers are advised not to scratch or rub skin or eyes until after thoroughly washing in the shower.
Health and safety issues for installers are a major disadvantage of installing fiberglass insulation. Issues include potential cancer risk from exposure to glass fibers (based on animal studies) and formaldehyde off-gassing from the resin used in the backing and petrochemicals in the resin. Direct contact with fiberglass and exposure to airborne fiberglass dust can irritate the skin, eyes, nose and throat.
Problems using fiberglass insulation in basements and crawlspaces: Moisture problems in basements have lead experts to recommend against using fiberglass in basements and crawlspaces. The old standard installation of fiberglass batt insulation between framed stud walls on the basement interior with a vapor barrier over the studs is no longer recommended because of excessive problems with mold, mildew, decay and rot. To maintain its effectiveness, fiberglass must not be exposed to high-moisture conditions such as a damp basement. Moisture will negates the insulation value of fiberglass insulation and promote mold and mildew which degrade indoor air quality.
Don't use fiberglass insulation in metal buildings and pole barns. Pole barns and metal buildings require an insulation that addresses cold, heat and condensation. Once the fiberglass insulation gets damp (and it will in a pole barn) it will stay damp while trapped between the insulation's vinyl facing and the metal skin of the building. Not only will you have trapped moisture in the blanket causing rot, rust, oxidation, mold etc., the damp blanket will provide less and less R value as the moisture builds. Couple this with the fact that fiberglass insulation does not prevent radiant heat transfer (primary source of heat flow) and you can see why fiberglass insulation is not the recommended insulation for pole barns and metal buildings. Prodex Total insulation provides an R 16 that is unaffected by humidity, a vapor barrier and a radiant heat barrier. Prodex Reviews
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