The R-value for roof insulation and attic insulation should have a minimum value of 30.
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.
Yes, too much loft insulation can cause dampness in some situations. Loft insulation works by trapping warm air inside a building, preventing it from escaping through the roof. This helps to keep the interior of the building warmer in cold weather, reducing the need for heating and saving energy.
Yes, you can use R19 insulation in an attic, but whether it's suitable depends on a few factors: Climate Zone: R19 insulation is typically appropriate for attics in moderate climates. In colder climates, higher R-values (like R30 or R38) may be recommended to effectively prevent heat loss.
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.
Best Insulation For Roof Mineral Wool: A Natural Choice
It has an R-value of 3.1 to 4.0 per inch when blown in, and 3.1 to 3.4 per inch when installed in batts. If you're worried about mold and mildew growing in your home, mineral wool might be the best insulation material for your roof.
Roof and ceiling insulation. Installing roof and ceiling insulation can save up to 45% (or more) on heating and cooling costs.
The dip from R10 to R4 seems odd, as one would expect more R as you travel further north through the zones. Thicker is not better! Doubling the amount of insulation will double the R-Value, but so what? Doubling the insulation from R-19 to R-38 does NOT cut the heat loss in half (50%) it cuts it by around 3%!
If the federal recommendation is R60, then you can save yourself plenty of money on energy bills and HVAC repairs by having a minimum of R60 installed. This can be any combination of batts and blown-in insulation.
You will want to bring up your attic up to R-38:
If your attic has 5-6″ of existing insulation, you'll want to install an R-19 to achieve a total of R-38.
Can I put plywood over insulation in the attic? Yes you can install plywood subflooring directly over the floor joists and insulation on your floor. You need to install rigid insulation boards on top of the attic flooring joists and then install plywood over the top.
It's important to leave a ventilated air gap between the insulation and the boards to prevent condensation on the underside of the boards.
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.
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 the case of roofs, a typical recommended thickness is between 140mm to 200mm to attain the desired U-value of 0.16 W/m2K.
1. Asphalt Shingles: Common in residential buildings, asphalt shingles generally offer an R-value of about R-0.44 per thickness. While cost-effective and aesthetically versatile, they provide minimal insulation compared to more specialized systems.
National average costs for attic insulation range from $1 to $6 per square foot if you're planning to have it installed professionally.
Roof Insulation: What's The Difference? The biggest difference between these two types of insulation is where they are installed. Attic insulation is installed in the ceiling plane, while roof insulation is installed on the roof slope itself, above and below the rafters.
The R-value for roof insulation and attic insulation should have a minimum value of 30.
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.
The DOE Insulation Fact Sheet (DOE/CE-0180) can be ordered from the Energy Efficiency and Renewable Energy Clearinghouse or accessed from the Internet at www.ornl.gov/ roofs+walls. Fiberglass and rock wool batts—2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.
Excessively thick insulation can block most ventilation sources, reducing air quality and restricting air exchange within the loft.
(Source: NRCA.) In the event you are erecting a “cold building” (such as a refrigeration building) that stays at 32 F (0 C) degrees or less inside, you will need a vapour barrier on the outside of the insultation to prevent warm exterior air from entering and potentially damaging the roof's insulation. (Source: NRCA.)
As a general rule, insulation should be replaced or retrofitted every 15 to 20 years. However, it may need replacing or retrofitting sooner depending on the type of insulation installed, the R rating of the original insulation, compression and movement over time, and whether any damage has occurred.