This page is a repository for supporting documents for Appendix R - Strawbale Construction, approved for inclusion in the 2015 International Residential Code (IRC). A Code Change Proposal for this appendix was submitted to the International Code Council (ICC) on January 3, 2013, with final revisions made on Feb 27, 2013. The proposal was approved with a 9-1 vote by the IRC Building Committee at the ICC Committee Action Hearings in April 2013. On October 4, 2013 the proposal received final approval at ICC's Public Comment Hearings.
Here you will find testing reports, research papers, professional and academic journal papers, support letters from licensed design professionals, and other references. This page was established on Dec 26, 2012. (Most recent update - June 4, 2014)
Please direct all inquiries to Martin Hammer:
Approved Strawbale Construction Appendix for the 2015 IRC:
Text of the Strawbale Construction appendix for the 2015 International Residential Code (IRC), as approved on October 4, 2013 at the ICC Public Comment Hearings. Illustrations and commentary are expected to be added for the Code and Commentary version of the 2015 IRC.
Support Letters from Licensed Design Professionals
Supporting Documents by Category:
(**Indicates document in direct support of proposed and approved code language**)
Moisture Monitoring - Ridge Winery
The Ridge Winery near Healdsburg, California is one of the largest straw bale structures in the world. With straw bale walls up to 23 feet high, coatings of different types of earthen and lime plasters, and many different moisture loading conditions.
Moisture Properties of Straw and Plaster/Straw Assemblies
Tests of straw bales and plastered straw, for capillarity, permeability, and sorption isotherms (John Straube, PE)
Load-Bearing Straw Bale Construction
A summary of worldwide testing and experience (Bruce King, PE)
Out-of-Plane Load Test
Test report of walls with different combinations of plaster and mesh to resist out-of-plane loads. (Kevin Donahue, SE)
In-Plane Cyclic Tests of Plastered Straw Bale Walls - U. of Illinois Testing report on 3 earth-plastered and 3 cement-plastered 8'x8' straw bale wall specimens (Cole Ash; Mark Aschheim, PE; David Mar, SE)
In-Plane Cyclic Tests of Plastered Straw Bale Walls - U. of Washington
Thesis on testing of 2 cement-plastered 8'x8' straw bale wall specimens (J.Ramirez)
In-Plane Cyclic Test of Plastered Straw Bale Wall - California Polytechnic University
Thesis on testing of cement-plastered 4'x8' straw bale wall specimen (S.Faurot; K.Kelly; H.Kim)
In-Plane Monotonic Test of Plastered Straw Bale Wall - California Polytechnic University
Thesis on testing of cement-plastered 8'x8' straw bale wall specimen (J.Nichols; S.Rapp)
Shake Table Test Video of Full Scale Building Specimen - U. of Nevada, NEES Facility
Video of 14'x14'x10' clay-plastered straw bale building specimen constructed with system developed for earthquake affected Pakistan (Darcey Donovan, PE)
Derivation of minimum total length for strawbale walls used as prescriptive braced wall panels in the IRC. (M.Aschheim, PE; M.Hammer, Architect )
** Seismic Design Factors and Allowable Shears for Strawbale Wall Assemblies** Recommended seismic design factors and allowable shears, including P695 analysis and analysis of in-plane testing results. (Mark Aschheim, PE, et al)
Analysis of testing of mesh attachment to boundary members. (A.Parker, M.Aschheim, PE, et al)
Analysis of stiffness compared with plywood shear walls and concrete shear walls. (K.Donahue, SE)
Properties of Earth, Lime, and Lime-Cement Plasters
Compressive strength, modulus of rupture, shrinkage, erosion, and modulus of elasticity. (Kelly Lerner, Architect; Kevin Donahue, SE)
Fire Test Results... Show Fire Test Video
1-Hour Fire Resistance of a Straw Bale Wall with Earth Plaster
1-Hour ASTM E119-05a fire test report for non-loadbearing earth-plastered straw bale wall specimen.
2-Hour Fire Resistance of a Straw Bale Wall with Cement Plaster
2-Hour ASTM E119-05a fire test report for non-loadbearing cement-plastered straw bale wall specimen.
ASTM E84 test report for flame spread index and smoke developed index.
Thermal Performance of Straw Bale Wall Systems
Results from thermal tests, particularly the Oak Ridge National Laboratory test, are reviewed, analyzed, and discussed in a summary report.
Design of Straw Bale Buildings
Book showing current understanding of all technical aspects of straw bale construction, including: Structure, Moisture, Fire, Insulation, and Plasters, with frequent reference to testing. (Bruce King, PE, et al) (available for view and purchase via link above)