IBC Code 2021 Updates

Summary: IBC Code Section 2510.6 Changes

IECCmap Revised A and C Map WEB 01 This map indicates three major climate zones for the U.S.: A: Moist, B: Dry, C: Marine. The major code change is for the highlighted Zones A (Moist) and C (Marine).The 2021 International Building Code (IBC-2021), Section 2510.6, was recently updated reflecting changes in Water Resistive Barriers (WRB) selection for stucco over wood-based sheathing.

The major code change is for Zones A (Moist) and C (Marine). Now required is ONE of the following:

Option 1: 3/16” (4.8mm) drainage cavity over the WRB when stucco is applied on wood-based sheathing such as OSB and plywood
Option 2: Minimum drainage efficiency of 90 percent as measured by ASTM E2273 or Annex A2 of ASTM E2925

Vaproshield Solutions For Zones A and C

Rainscreen SA air barrier WRB with 7mm drainage matrix will satisfy BOTH options for Zones A and C. The aggressive adhesive bonds to multiple substrates including OSB and the built-in 7mm drainage matrix allows for one-step installation of the: air barrier, WRB and required 3/16” (4.8mm) drainage cavity or minimum drainage efficiency of 90%.Two rainscreen drainage matrix options: 7mm and 3mm work with stucco, siding, and stone. The 3mm offers a cost-effective option meeting the minimum drainage efficiency of 90 percent, as outlined above Option 2.

Rainscreen SA Benefits

Factory-bonded drainage matrix (3 or 7mm) maintains an unimpeded vertical drainage plane behind the stucco façade
Simplified installation with all-in-one membrane and fully tested rough opening flashing system
Applies in below freezing 20°F (-6°C) temperatures
Six months UV and weather exposure eases concerns of supply chain delays
Air barrier and WRB with high drying capacity, 25 perms

Rainscreen SA combined with Stockton Products™ new Tru-Weep™ single step installation counter flashing stucco screeds allow water to efficiently exit the stucco assembly and provide best practice installation.

Summary Zone B: Dry Climates

IECCmap Revised B Map WEB 01 The highlighted Zone B (Dry) had minor code updates offering four options.The changes for Zone B, dry climate, are not as drastic as Zones A and C however there are a few noteworthy details. ONE of the following shall apply for dry (B) climate zones:

Option 1: Two layers of 10-minute Grade D paper or greater
Option 2: Two layers of water-resistive barrier complying with ASTM E2556, Type 1
Option 3: Water-resistive barrier shall be 60-minute Grade D paper
Option 4: Water-resistive barrier shall have a water resistance equal to or greater than one layer of water-resistive barrier complying with ASTM E2556, Type II

Additionally, options 3 and 4 the WRB must be separated from the stucco by ONE of the following:

Foam Plastic
Another non-water absorbing layer
Drainage space

Vaproshield Solutions Compliant to IBC 2021 Section 2510.6 Water Resistive Barriers

VaproShield Membrane Solutions	Moist and Marine 2510.6.2 Option 1 3/16” (4.8mm) drainage cavity	Moist and Marine 2510.6.2 Option 2 Minimum drainage efficiency of 90%	Dry Climate 2510.6.1 Options 1-4