Insulation levels are specified by
Depending on where you live and the part of your home you're insulating (walls, crawlspace, attic, etc.), you'll need a different R-Value. Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces.
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.
I would not put anything less than R5. Even R6 if you can get it. Good insulation is one of the best bang for your buck improvements you can make. It really isn't worth saving a little on lower R values, for something you will have in there for 20+ years.
CEILING INSULATION THICKNESS
For instance, to achieve a U-value of 0.16 W/m²K for a flat ceiling, you'll need a minimum of 170mm thick mineral fibre insulation placed between the ceiling joists, along with an additional 100mm thick layer covering the joists.
Most climates require a vapor barrier to cover ceiling insulation, but not all insulation requires a vapor barrier. It's always important to refer to your state's building codes.
If you live in the Southern part of the U.S., the recommended insulation level is a minimum of R-38 or about 13-14 inches of insulation. If you live in the Northern part of the U.S., the recommended insulation level is a minimum of R-49 or about 16-18 inches of insulation.
The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space. While you might think that too much insulation can't be bad, there are some significant consequences to consider.
Blocked vents in a vented attic will lead to poor energy efficiency, moisture buildup in your attic space, and most importantly, it will lead to mold.
While both types provide insulation, R30 is the better option for maximizing energy savings in areas where heat loss or gain is a major concern. For example, R19 may suffice for interior walls, but R30 is more appropriate for exterior-facing attics or floors.
R-30 high-performance batts are 8-1/4˝ to 8-1/2˝ thick as opposed to standard R-30 fiber glass insulation batts of 9-1/2˝ to 10˝ (thickness may vary by manufacturer). The R-38 high-performance batts are 10˝ to 10-1/4˝ thick as opposed to stan- dard R-38 fiber glass insulation batts of 12˝.
When it comes to insulating ceilings, attics, walls, and crawlspaces, homeowners and builders often choose fiberglass batts. Besides being cost-effective, they prevent heat from passing through walls, ceilings, and floors. Generally, fiberglass batts come in 2*4 or 2*6, but you can cut them down if necessary.
The thermal barrier of a home should consist of a continuous layer of insulation on all sides—including the lowest floor, the exterior walls, and the ceiling or roof. Doubling the thickness of insulation will double the insulation's R-value, cutting heat loss in half.
You can use faced or unfaced batting when installing between the roof rafters of finished attic spaces. When using paper or plastic batting insulation, that moisture barrier should face outward toward the attic space. Even if the attic space is unheated, it's typically warmer than the outside air in winter.
The short answer is, yes, you can over-insulate your home. While your home should be well-insulated against the cold and keep you cool during hot summer months, that doesn't mean you should cram the walls full.
If we wish to label the strength of the association, for absolute values of r, 0-0.19 is regarded as very weak, 0.2-0.39 as weak, 0.40-0.59 as moderate, 0.6-0.79 as strong and 0.8-1 as very strong correlation, but these are rather arbitrary limits, and the context of the results should be considered.
Many of us know what causes mould; when moisture is trapped in the rooms of you home. Sometimes, there is insufficient insulation in the walls, so mould grows. However, not many people realise that additional insulation isn't always the answer. In fact, too much insulation can be the secret cause of mould.
If you decide to insulate the ceilings, they should have a minimum ceiling insulation R-value of 30.
The bottom line is the old insulation needs to be removed because it hinders the airflow into the attic, it can promote mold growth, and it is dirty.
When it comes to insulation, it's generally recommended to leave a gap between the insulation material and any other surfaces, such as walls, ceilings, or roofs. This gap provides ventilation and prevents moisture buildup, which can lead to mould and other problems.
Should I Put Vapor Barrier Plastic Over Insulation Before Drywall? Yes, covering your insulation with a vapor barrier plastic before installing drywall is crucial. It prevents moisture buildup that can lead to mold, rot, and even structural damage.
Install the vapor barrier on the warm side of the insulation.