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Compressed Earth Block Wall Systems

Presented By

Dan JohnsonDavid Romary

Driftless HomeWrightswww.driftlesshomewrights.com

One Element of Green Design

Earth Blocks

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Workshop Goals

1. Introduce Earth Block Construction.

2. Increase Understanding Of Building Material Thermal Properties. (especially masonry)

Adobe Earth Block BrickSun Dried Hydraulically Pressed Fired

Approximately Half the World’s Population lives in Earthen Structures

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Taos Pueblo

Longest continually occupied structure in North America.

Beginning1000 to 1450 AD

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21st Century

Cinva Ram/Hand Press

CEB Block Press

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Soils For CEBs

Range of Proportions

Gravel: 0-40%

Sand: 25-80%

Silts: 10-25%

Clay: 8-30%

(Source: CRATerre-EAG)

Stabilized Blocks vs. Unstabilized

Block Testing in Iowa

Stabilizers

Portland Cement

Lime

10% Soil Moisture is the Ideal for Stabilized Block Making

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Approx. CEB Compressive Strength(Based on MEB experience)

Stabilized 700-1400Unstabilized 500-1000Code 300

Why build with Earth Blocks in the Midwest?

•Sustainable Building Material•Thermal Mass•Architectural Freedom

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Sustainability

Sustainable Resource

Embodied Energy= the quantity of energy required to manufacture and supply to the point of use, a product, material, or service.

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Cement-making = 5% of Greenhouse Gases

Wall building “resource” taken from on site.

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Thermal Mass

Conductive Heat Loss

R-Value: Measure of thermal resistance.

U-Value: Measure of heat transfer.

R-value is inversely proportional to the U-value

R=1/U and U=1/R

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Thermal Mass

The capacity of a material to store thermal (heat) energy for an extended time.)

Passive SolarDesign

Thermal Mass is essential for heat storage and to prevent overheating

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Thermal Performance

Earth Block Steady State R-value does not reflect the thermal performance of a CEB wall.

Wall design determines a CEB wall’s performance.

Greenhouses

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Masonry Heaters

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ArchitecturalFreedom

Foundations

Footings•10” thick•33% larger the stem wall

Stem Wall•Centered on Footing•Can be 2” less then CEB wall width.

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Foundation Options

•Footer and Stem Wall

•Rubble Trench

•Frost Protected Slab onGrade

Mortar Options

Dry Stack

Slurry

Mortar

Wall showing slurry method.

Slurry•Same soil as block.

•Screened to 1/8”

•Mixed like a bad

milk shake

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Dry StackSays it all

Important to avoid point loads by keeping courses level and free of gravel, dirt chunks, twigs, etc.

Mortar

Lime Based Clay BasedPortland Cement Based

Dan’s Lime Mortar1 part Lime Putty

2.5-3 parts Sharp Sand

Clay Mortar

1part clay dirt

1-2 parts Sharp Sand

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Bucks and Bond Beam

Lintels(See Code For Sizes and Length)

CEB Construction Considerations for the Midwest

1. Moisture2. Thermal Performance (Thermal Mass)

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Moisture Considerations

Block Testing in Iowa

Roof Overhangs and Gutters

Air Sealing Wall Penetrations

Wall penetrations are the number one source ofmoisture movement into the cavity of a wall.

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We want to limit the amount of moisture entering the wall, while still maintaining a breathable wall.

LikeSkin

Base Coat: Lime Plaster and Exposed Block

Earth Block Inc./Jim Hallock

Exterior Finish

-Plaster/RenderLime Based

-SidingReclaimed WoodLocal WoodCement Fiber

Double Wall System

Advantages

1. Several Insulating Options

2. Chase for Electric

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Insulating Options

Insulation R-value-Perlite 2.7-Vermiculite 2.7-Rock Wool 4-Icynene 3.6--Dense PackedCellulose 3.5

-Sawdust &Lime 3.0?

Interior Veneer CEB System

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Thermal Mass plus Insulation

Excellent! Wall System

“ . . . thermal mass and insulation are natural allies. The better a building is insulated, the higher are the chances for energy savings (thermal mass will be much more energy efficient than lightweight building envelope technologies).”

ORNL- Buildings and Technology Center

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Massive Cavity/Double Wall SystemMinneapolis, MN Climate

Steady State R-value of 19

Dynamic R-value of 30.07

Source:Oak Ridge National Laboratories

Double WallwithElectric and Phone Wiring

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CEB Radiant Veneer WallDrywall Alternative

Lime Plastered Veneer Wall with Radiant Tubes

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CEB Floor

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Pella, IA 2005