Attic floor spray foam insulation application through a vented attic building science and design principles that your builder architect subscribes to can often dictate the method of spray foam used in the attic.
Foam insulation for attic floor.
After the foam is cured loose fill fiberglass or cellulose insulation gets installed on top of the foam.
Building scientists the experts who study how buildings use and lose energy have known for years that a house loses more energy through the attic than anywhere else.
The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation improvements in hvac equipment more airtight construction new materials and assemblies.
If you want to use the flash and batt approach you can use closed cell spray foam for a portion of the needed r 49.
Not on the floor of the attic.
Insulation is used on the attic floor to insulate the ceiling from the seasonal cold and or heat in a traditional vented attic setting.
This application effectively seals off the attic from the outdoors and eliminates air leakage and infiltration through the attic and roof areas.
Often the r value of fiberglass insulation is too low and requires the rafters to be retrofitted making foam board a better choice.
It is an excellent installation option for the attic because it is lightweight easy to work with and offers high r values.
Look up and from eave to eave there is foam insulation but none below you.
Senior engineer manager at icynene john broniek makes the case for the unvented attic assembly and why insulating the underside of the roof makes sense.
If you live in the northern half of the u s building codes require at least r 49 of roof insulation.
The spray foam is on the underside of the roof deck.
Each silverglo insulation panel is sealed to attic framing and to neighboring panels creating a thick layer of insulation that includes a radiant barrier.
When it comes to the various types of attic insulation used throughout building structures one of the most popular to use is spray foam insulation.
The case for unvented attics.
Only spray polyurethane foam can be used for this application as batt insulation will end up sagging and blown insulation simply can t adhere to the roof decking.
Spray foam has been used for the past 30 years due to its ability to rapidly expand and fit into a given space such as in an attic or other areas of your home and or building.
The foam portion would have to be r 30 in climate zone 7 or r 25 in climate zone 6 or r 20 in climate zone 5.
The attic is inside the thermal envelope and all the mechanicals and electrical are free and clear less a few wires that go out to the eaves and the vent stacks.
This means installing spray foam to a depth of at least 2 on the entire attic floor to completely seal everything up.