HomeMy WebLinkAboutFile Documents.155 Lone Pine Rd.0318.2017 (5).ARBKV2 modified 12/10/13
THERMAL RESISTANCE OF ASSEMBLY PROPOSED ASSEMBLY @ 70O INTERIOR TEMPERATURE
MDT DP @ DP @ DP @ DP @ DP @ TI
LAYER R-value 20% RH 25% RH 30% RH 35% RH 45% RH
Outside air layer 0.17
Roofing Month FO FO FO FO FO FO FO
Water-proof membrane 0.21 January 19.8 30 33 37 41 48
(optional) roofing nailer sheathing February 23.1 30 33 37 41 48
(optional) Outside rigid insulation March 29 30 33 37 41 48
Roof Sheathing 0.77 April 38.9 30 33 37 41 48
(optional) Inside vapor impermeable insulation 34 May 48 30 33 37 41 48
June 56.1 30 33 37 41 48
Condensing surface is above this line July 62.2 30 33 37 41 48
August 60.4 30 33 37 41 48
(optional) Inside vapor permeable insulation 19 September 53.6 30 33 37 41 48
Ceiling Finish (gyp bd)0.56 October 44.1 30 33 37 41 48
Inside air layer 0.61 November 30.7 30 33 37 41 48
Mean Daily Temperature (January)19.8 December 22.1 30 33 37 41 48
Total R value of assembly 55.32
MDT Mean Daily Temperature
Sum of insulation R values must be 49 or greater DP Dew Point
(or match Rescheck/Comcheck)RH Relative Humidity
TI Temperature of Sheathing/Insulation Interface = 70 - [(R-value)/(R-total)*(∆T)]
Temperature of condensing surface ∆T 70 - MDT
(must be greater than 41 degrees)
53
51.7
Use this to determine if an unvented roof assembly will have condensation problems. Enter the R value of each
component of your assembly. You may use rigid insulation above the roof sheathing, impermeable insulation
below the roof sheathing, or a combination. Enter the R values in the white boxes. Print the first page only.
City of Aspen Area Weighted U Value Calculator