But several readers mentioned that going overboard with insulation and sealing a house can cause serious problems – from moisture buildup and mold to polluted indoor air. It's vital when upgrading your insulation to get just the right amount and to ensure that it's properly installed.
It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.
Installing Insulation
Improperly installed insulation can have a negative effect on a home with regards to mold growth. For example, gaps left in the insulation can create cold spots that can lead to condensation and surface mold growth.
Moisture and insulation
Improperly installed insulation is one of the leading causes of condensation in the attic, especially when too much insulation traps warm air up near the roof and forces condensation.
Moldy and Dirty Insulation
In some cases, the top few inches can be removed and retrofitted, but this might cost more than replacing all of it in the area. Often, the mold or dirt you find and worry about is harmless. In any case, you should not try removing it yourself just in case it is dangerous black mold.
The short answer is no but spraying foam insulation over mold isn't a magic cure. Will spray foam kill mold? Yes, because spray foam creates an air seal and will starve that mold of its food source -- moisture and oxygen -- and will inhibit any future growth, it will also cause the mold to become dormant.
Black Spots on Insulation caused by Air Leakage
Particulates released by combustion appliances, such as wood stoves, boilers, furnaces, diesel heaters or auto exhaust, can produce very fine soot that can build up over time in insulation. Tobacco smoke can also contribute.
Does Loft Insulation Directly Cause Damp? The simple answer to this is no. Loft insulation in itself is not responsible for damp appearing in your property – however, it can be a contributing factor when it comes to the spread of damp via condensation.
Lofts can't just chip off a layer of insulation, so the need to breathe is far more important. So, can too much loft insulation cause condensation? Yes it can, and it can cause havoc in your home as well.
Spray foam insulation forms an entirely protective barrier against moisture and is unaffected by humidity due to its chemical make-up. This means that it can't rot and mould can't grow on it, no matter how long the foam has been in place.
Douse the insulation in a bleach solution (1 cup bleach and 1 gallon hot water) and scrape clean with a wire brush.
When portions of insulating material harbor mold spores, then you should replace it. Even if the material dries out, mold spores can become airborne and travel to other wet areas of the house. If you catch it early enough, then you'll only need to replace a small section of material, keeping your cost lower.
Unless your home was specially constructed for energy efficiency, you can probably reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years.
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.
Installing attic insulation this winter is a worthwhile long-term investment because it can significantly decrease your heating bills. As an added benefit, when the hot D.C. temperatures come back, the attic insulation will also minimize your air conditioning bills.
Current government recommendations are for loft insulation to achieve a depth of between 250mm and 270mm but some new properties are increasing their level of loft insulation to 300mm. Again, as long as the loft has adequate ventilation, this is fine. You may lose a little storage space but you will save money!
Past a certain point, insulation in a vented attic will do more harm than good. In most of the United States, achieving an R-Value of 38 is more than sufficient.
Insulation needs to be breathable. It also needs to discourage condensation. Modern insulation is the work of the devil in this regard. We constantly battle modern insulation.
Wet insulation in the attic can be dried out with the help of a fan or a dehumidifier. For some attics, you can remove the wet batts and keep them in a warm area to dry out. After a few weeks, you will need to monitor the insulation.
The simple answer is 'yes'. Insulation is not designed to last forever, eventually it will begin to degrade and whilst you may not always be able to see the deterioration, you'll certainly notice it.
What Can Go Wrong With Underfloor Insulation? Worst case scenario you trap moisture from spills or interstitial condensation up against the timbers within hydrophobic insulation and in turn risk rotting the floor joists.
Stachybotrys chartarum typically appears black or extremely dark gray in color. This mold tends to have very round splotches with a speckled appearance. Often, you see darker layers of mold over lighter layers.
Unless damaged, it can last 80 to 100 years in most houses before it needs to be replaced. However, insulation can start falling from fiberglass batts after 15 to 20 years, so if your insulation was installed in batts well over a decade ago, it might be time for an inspection or a home energy audit.
Black mold, as the name implies, is often dark in color. When searching for black mold, look for circular-shaped spots that are black, dark green or dark brown. Some black mold can also take on shades of orange or have flecks of white within it. Most of the time, black mold has a slightly furry appearance.