roof insulation is no-contest. The floor wins every time. Insulating the floor is standard practice for an unfinished attic space. The exception to this rule takes place when families opt to convert an unfinished attic space into something usable or livable.

What type of attic insulation is best?

Spray foam offers the best attic insulation performance available. Choose from two types: closed-cell and open-cell, aka 2-pound and ½-pound, respectively. They sport insulation values of approximately R-6.5 and R-3.6 per inch, respectively.

What insulation should I use in my ceiling?





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.

Should I insulate my attic floor or ceiling?

roof insulation is no-contest. The floor wins every time. Insulating the floor is standard practice for an unfinished attic space. The exception to this rule takes place when families opt to convert an unfinished attic space into something usable or livable.

Is it OK to insulate roof rafters?

Insulating between rafters will do no good, because the attic should be ventilated, and the rafter insulation would be between two unheated spaces. You can add insulation to the floor; the more the merrier. Just don’t put it in the eaves. Also, make sure the attic is well ventilated.

Can you have too much insulation in your attic?

It’s possible to over-insulate an attic as too much will cause moisture buildup and eventually result in mold. Eventually, adding more insulation leads to diminishing returns in trapping heat as well.

How thick should my ceiling insulation be?





about 10 to 14 inches

The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.

Does ceiling insulation need a vapor barrier?

Fiberglass Insulation



In most climates, it needs a vapor barrier. Some builders rely on batts with attached kraft-paper facing to do that job, but Tom recommends unfaced batts, covered in plastic with all the seams taped shut.

Is it better to insulate ceiling or roof?

If you are deciding between insulating the roof deck or the ceiling, Insulating your ceiling should be the priority. Not only is it easier but ceiling insulation is beneficial in a number of ways: Keeps the temperature in the building regulated. Saves on energy costs.

What is the best way to insulate the attic rafters?



Quote from the video:
Quote from Youtube video: Place the craft faced insulation. Down between the joists on top of the drywall. And with the facing down toward the interior of the house be careful not to compress the insulation.

Should you insulate roof joists?

Insulating between the joists of your loft will keep your house warmer, but make the roof space above colder. This means pipes and water tanks in the loft space could be more likely to freeze, so you will need to insulate them.

Should I remove old attic insulation before adding new?

Expert contractors that specialize in insulation advise that removing old fiberglass insulation is best before installing new cellulose insulation because of possible mildew, mold, or rodent excrement.

How do you insulate attic floor boards?



This could be accomplished by boring holes in the floorboards and inserting the nozzle of an insulation blower machine into the holes. The insulation will fill up the cavities. This would yield the best bang for the buck, as it would place the insulation immediately above the area where it is needed most.

Is spray foam insulation in attic worth it?

A properly done spray foam job not only insulates but also greatly reduces the air leakage of a home. But that only works if the installer can get it into the places where most of the air leakage happens. In an attic, the eaves are one of the most critical places to get good coverage with the foam.

Can you insulate the attic floor and roof?

Do you have any plans for furnishing/fitting out your attic in the future? Then you could simply insulate the pitched roof. But the best solution is actually to insulate both the attic floor and the underside of the roof. In this way you prevent the heat from the rooms below escaping to the attic rooms above.

What are the disadvantages of spray foam insulation?

List of the Cons of Spray Foam Insulation

  • Spray foam insulation does not always fill every possible cavity. …
  • Spray foam insulation might encourage water damage for some homeowners. …
  • Spray foam insulation can sometimes shrink. …
  • Spray foam insulation requires a lot of experience to get it right.

Can you spray foam an attic floor?



(Source: Building Science Corporation.) One technique that can both increase attic insulation and air seal the attic is to apply a layer of spray foam to the attic floor, then to install additional blown-in or batt insulation to meet or exceed insulation R-value requirements.

Can I use rigid foam insulation in attic floor?

You can use foam board in the attic. It is an excellent installation option for the attic because it is lightweight, easy to work with, and offers high R-values. Often the R-value of fiberglass insulation is too low and requires the rafters to be retrofitted, making foam board a better choice.

Where should you not use spray foam insulation?

When NOT to Use Spray Foam Insulation

  1. For areas that are too close to electrical boxes:
  2. For areas too close to ceiling light boxes:
  3. Open-cell spray foam on your roof:
  4. For closed-cavity spaces:
  5. If you have a history of skin, respiratory, or asthma problems: