Tag Archives: light straw clay

Rocky Mountain Natural Building Conference

A 3 day networking, learning, and sharing event. Local and regional builders and experts will the presenting. Topics include affordability of natural building, design with natural materials, insuring natural homes, biomimicry, building science with natural materials, healthy and non-toxic homes, and more.

Visit the website of Colorado Straw Bale Association for full event info!

Legalizing Sustainability: Part 1

Natural buildings have long been restricted to code-less municipalities (mainly rural, libertarian areas), and to those who have the financial resources to pay for extensive engineering. Even with approved, stamped engineer plans, building officials still have retained the power to say no to natural homes.

Webb_Municipal_BuildingThat has been changing all over the United States recently, and here in Denver it looks like we are further opening the door.

Within the next year, the City of Denver will be adopting the 2015 International Building Codes (I-Codes). The I-Codes are a huge set of rules to help ensure buildings are built safely, and they will mean an enormous overhaul to the current building codes in Denver.

Due to the hard work of a lot of devoted individuals, the 2015 I-Codes include two appendices related to natural building. One of these is on strawbale and the other is on light straw clay. These appendices give folks parameters on which to design code-approved strawbale homes and use light straw clay insulation. This means you can not only receive a permit for this type of construction, but also that the city MUST issue you a permit if you are following the code.

Here is the catch. Municipalities are not required to adopt the appendices of the I-Codes.

20150320_152214Advocacy is one of Common Earth’s main goals, so we jumped right on in to this process and submitted a proposal to the City of Denver requesting that they outright adopt both of these appendices. The proposal was accepted and reviewed by a committe on March 20th, 2015. There were some important concerns raised around how to inspect these unfamiliar construction techniques, but the committee overwhelmingly supported these appendices and approved both of them! If these appendices make it through the rest of the review process (more on that to come), we hope to be able to fill in the gaps and offer the city inspectors a training on how to properly inspect for these appendices.

This is a huge step towards natural building becoming more widely accepted, and it can’t be said enough that we are building on the hard work of a lot of individuals who came before us. Not just the folks who ingeniously started stacking bales over 130 years ago, or the generations of builders and craftsmen that refined wattle & daub into light straw clay as we know it today, but we particularly owe enormous gratitude to those who have labored over writing and gathering support for these appendices. To name just a couple: Martin Hammer and Paula Baker-Laporte. Please check back in to hear about the public review process as the codes continue on to City Council. We invite you to become more involved and help us build on the exciting momentum towards change in the building industry!



Light Straw Clay Workshop Report

Slip straw is a great beginning natural building technique because it is quick to learn, simple, Light Straw Clayand can be used in new buildings or to add non-toxic insulation to existing buildings. Ben Waldman, contractor and natural builder, taught a slip straw workshop at the GrowHaus in Denver last month.
Workshop participants included permaculture students, landscapers, farmers, and people who wanted to explore options for building projects they have coming up.

Mixing Clay SlipSlip straw is made by combining fiber (preferably wheat straw) with a runny clay slip. The hollow shaft of the straw creates air pockets, while the clay binds the fiber together and adds thermal properties.

Once the straw and clay slip have been mixed to the right consistency, the mixture is added into a wall’s framing and then tamped down.

Slip straw is not load bearing on its own, but is meant to be used as an infill for framed walls. Different framing designs were discussed, along with their advantages and disadvantages for combination with this technique.

Once the straw has been fully tamped into the wall, it will be finished with a clay or lime plaster. Clay is able to control moisture on its own, which helps protect infill of the wall against mold or Mixing Plasterrot.

Clay plaster is another huge topic that will be taught at a future workshop, but students in this class got to have some hands-on introduction.

Burlap coated in clay slip was added over wood framing members to help bind the plaster to the wall.

Students left the workshop having gained firsthand experience with natural materials, knowledge of how to achieve the right mixtures for slip-straw and the steps involved in applying this method for better wall insulation, and access to additional resources.

Light Straw Clay Workshop

In this hands-on workshop, participants will learn how to use straw and clay in combination to create a low cost, low impact non-toxic insulation called “light 6a013487c4922b970c017743005b5f970d-800wistraw clay”. Participants will understand the variety of applications light straw clay can be used in. The hands-on portion of the workshop will include mixing and installing light straw clay in a conventional wall system, and installing a basic clay plaster finish over the light straw clay wall system.




In this hands-on workshop, participants will learn about the following topics:

  • Properties of slip-straw construction
  • Properties of clay plasters
  • How to retrofit an existing home
  • How to install in a new home
  • Building code compatibility
Saturday, January 24th 2015
10:00am to 1:00pm
The GrowHaus – 4751 York Street, Denver CO 80216
$35 for DPG members
$40 for non-members