# What R Value Do I Need For Walls?

## What kind of insulation do I need for walls?

In the case of walls, the composition can also impact the R-values needed for optimal energy efficiency.

The most common insulation materials are fiberglass, cellulose and foam.

Insulation types include loose fill, batts, rolls, foam board, spray board and vapor barriers..

## What is the R value of 1/2 inch drywall?

Total R-Value of Composite WallMaterialR-Value (ft2 o Fh / BTU)Asphalt Roof Shingles0.441/2 inch Gypsum Board (Drywall or plasterboard)0.45Wood Siding, 1/2 inch0.81Plywood, 3/4 inch0.948 more rows

## What is the best house insulation?

The best types of home attic insulation are open cell spray foam, fiberglass, and cellulose. Cellulose is the oldest insulation material used for not only the attic but other areas of the home as well.

## How do you calculate the R value of a wall?

1/R-value = U-value. For example, an R-5 wall has a U-value of 1/5=0.2. U-value has the unit of BTU per hour per degree F per square foot (BTU/hr/F/sq. ft.).

## How dangerous is insulation?

There is no evidence currently of long-term damage from inhaling fiberglass particles, and workers who come into regular contact with fiberglass insulation are not considered to be at any higher risk of lung and breathing problems, especially if they wear proper safety attire.

## What is the R value of an uninsulated wall?

An uninsulated standard 2×4 wood-frame wall has an R-value of about 3, so our starting point of R-2 in the first graphs is close to that of an uninsulated wall. This first graph shows cumulative reduction in heat flow.

## Does drywall add R value?

While all building materials have some kind of R-value resistance to heat movement, insulation greatly increases the R-value of a wall, ceiling, floor or other building components. As one example, drywall at 1/2″ thickness has an R-value of 0.45—a fairly low value.

## Is R 13 insulation good?

Although the U.S. Department of Energy rates R-13 insulation as “good” for use in walls in southern areas of the country, it rates R-19 insulation higher, designating it as “great.” That is because R-19 insulation provides more thermal insulation than R-13 does.

## Does a 2×4 have an R value?

A 2×4 stud (i.e., 3.5″ deep) has an R-value of 4.4.

## What is the cheapest insulation for walls?

Fiberglass battsFiberglass batts are typically the cheapest insulation, but a loose corner or tear can diminish the insulation quality.

## What is the highest R value for a 2×4 wall?

Fiberglass vats are the standard insulator for 2-inch by 4-inch wall framing, and are rated R-11 through R-15. In order to achieve the higher insulation R-value of R-21 a different type of insulation will be required.

## Can you put r19 in a 2×4 wall?

The normal R19 in a 2×4 wall will actually be far below R19 – probably no better and possibly lower than R13 insulation. R19 in a 2×6 wall does not really give you an R19 wall. … If it is a 6″ steel stud wall, it could be as low as an R11 wall.

## Can you put r30 insulation in 2×4 walls?

“R” is a value – Not a thickness or a material. Rigid fiberglass and rock wool are much thinner (yet much more dense and much more effective) than ‘fluffy” stuff. R-30 fiberglass insulation is designed to be in a roof or ceiling cavity framed with 2x10s. It is way too thick for 2×4 walls.

## Can I use 2×6 insulation in a 2×4 wall?

Fiberglass and rock wool batts – 2×4 walls can hold R-13 or R-15 batts; 2×6 walls can have R-19 or R-21 products. Generally, batt insulation is the least expensive wall insulation material but requires careful installation for effective performance.

## Does Wall insulation make a difference?

In order to have this kind of insulation, you need to make sure you have uninsulated cavity walls. Houses built from 1990 onwards usually already have insulation in the walls to keep heat in, which not only keeps the home warmer for longer, it can make a big difference to your heating bills.