The higher the r value the better the thermal performance of the insulation.
Wisconsin attic insulation code.
You can mix the type and material of insulation too.
The 2015 irc requires r 49 insulation for ceilings with attic spaces.
The table below shows what levels of insulation are cost effective for different climates and locations in the home.
Sps 322 39 apply to any dwelling with insulation installed whether or not the insulation is required under this code.
This map shows thermal recommended levels of insulation for various climate zones based on recommendations from the u s.
Recommended levels of insulation.
Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.
R value is a measure of insulation s ability to resist heat traveling through it.
Make sure your home is properly insulated in all these locations.
The first state building code in wisconsin was established in 1914.
Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1.
Achieving greater r values in attics.
Insulation ratings can be improved by adding more layers of insulation.
The iecc is the model building code for the united states.
An unheated and unfinished attic space in wisconsin needs insulation rated between r 49 and r 60.
R 38 shall be deemed to satisfy the requirement for r 49 wherever the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves.
However there is an exception.
Comcheck can be used for commercial buildings or high rise 3 stories multi family buildings.
Comcheck is federal department of energy doe software approved in wisconsin for demonstrating compliance with commercial building envelope requirements and interior exterior general lighting requirements only hvac portions of the program are not acceptable.
Department of energy doe and the international energy conservation code iecc.
Insulation level are specified by r value.
Insulation rated at r 60 can place too much weight on a plaster ceiling which can cause the laths under the plaster ceiling below to loosen from the ceiling joists.
Sps 322 38 do not apply to an unheated space such as an attached unheated garage.
You should select a loose fill r 49 insulation product.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
The ideal attic insulation r value is different than the ideal wall insulation r value.
A r 38 will satisfy the ceiling r value requirement for a dwelling where the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves.
Sps 322 01 3 b b the vapor retarder requirements under s.
