Roof Thermal Insulation Values

The higher the r value the better the thermal performance of the insulation.

Roof thermal insulation values.

You can achieve better thermal performance in your attic by adding an additional layer of insulation. An insulating material s resistance to conductive heat flow is measured or rated in terms of its thermal resistance or r value defined as ft f hr btu. In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation. Achieving greater r values in exterior walls.

This means that the higher the u value the worse the thermal performance of the building envelope. The effective r value refers to the insulation value that is actually achieved. Existing 3 4 inches of insulation. It can also be referred to as an overall heat transfer co efficient and measures how well parts of a building transfer heat.

Or pour fill insulation. Carlisle s tapered insulation helps promote rooftop drainage while providing excellent insulating value. A rigid roof insulation board with high thermal efficiency johns manville r panel is compatible with multiple types of membrane systems. Or square feet degrees fahrenheit hour btu.

Insulation or other building material 9. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. The higher the r value the greater the effectiveness of the insulation. Icynene foam to mineral wool insulation.

For instance if you have a material with an r value of 12 attached to another material with an r value of 3 then both materials combined have an r value of 15. The r value depends on the type of material its thickness and its density. May not be left exposed in living area. R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems.

Regardless ashrae s new above deck roof insulation standard is a good place to start as it jumped 33 percent from r 15 to r 20 in five of six climatic regions. A u value is a measure of heat loss in a building element such as a wall floor or roof. Tapered polyiso minimizes the negative effects of ponding water and extends the service life of a roof. Add insulation to attic.

Design r value refers to the r value intended for the building or sub component such as the roof assembly by the architect or other design profes sional. Very good air bypass leak sealing properties. Aging effects comments. Recommended insulation levels for retrofitting existing wood framed buildings.