HomeMy WebLinkAboutFile Documents.520 S Original St.0110.2018 (15).ARBKS
THERMAL RESISTANCE OF ASSEMBLY PROPOSED ASSEMBLY @ 70
O 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
Metal Roofing 0 Month F
O FO FO FO FO FO FO
Water-proof membrane 0.21 January 19.8 30 33 37 41 48
3/4 Sheathing 0.94 February 23.1 30 33 37 41 48
Spray foam 49 March 29 30 33 37 41 48
April 38.9 30 33 37 41 48
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
Air space August 60.4 30 33 37 41 48
R-19 UF batt September 53.6 30 33 37 41 48
5/8" GPDW 0.56 October 44.1 30 33 37 41 48
November 30.7 30 33 37 41 48
Mean Daily Temperature (January) 22.5 December 22.1 30 33 37 41 48
Total R value of assembly 50.88
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)
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.
SHEA RESIDENCE ‐ 520 S. ORIGINAL ST. UNIT A
49
69.5
04/20/2018