Eaves width can be a deal breaker in that if the eaves are not wide enough to accept the insulation the cost of extending the eaves can outweigh the benefit of the insulation.
External wall insulation depth.
The ones that let in air from the outside world.
When you are insulating two by four 2x4 and two by six 2x6 framed exterior walls and want to use fiberglass insulation what thickness is best the question becomes all more critical because of the permanent nature of wall assemblies and wall insulation.
There are four main methods of installation the most common but not always the most effective is building a new stud wall to which insulation can be added.
Our guides to building regulations in england adl1a 2013 building regulations.
England new dwellings.
You can do this internally or externally for instance by insulating the inside or the outside of your external walls.
External wall insulation the external walls of a building are an important part of a building s overall design and since there are a variety of different ways to construct an external wall with a range of building materials it should come as no surprise that there are many different ways to insulate them.
With that in mind when we use the word external we just mean the outside of the external walls of your house.
Measure the depth of your current insulation.
For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed your attic to reach r 30 if you live in zones 2 or 3.
These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.
Most manufacturers produce an r 13 batt that fits into a 2 by 4 wall cavity which is.
Measure the area needing insulation.
Standard fiberglass insulation batts or blankets provide an r value of 2 2 to 3 8 per inch of thickness.
Internal wall insulation involves the application of insulation to the interior face of external walls in order to improve the thermal performance of the property.
Just to be clear we only recommend insulating the external walls of your house ie.
R 38 is the industry standard and the minimum thickness for r 38 is 12 inches.
Calculate additional insulation needed.
If your current insulation is only 5 inches deep you ll need to add seven inches of insulation to achieve the 12 inch r 38 rating.
A word about words.
External insulation will add thickness to the wall most evident at the reveals and eaves.
The thickness of thermal insulation is dependent on whatever type is required in order to create.