Hacking the Earthship by Rachel Preston Prinz

Author:Rachel Preston Prinz
Language: eng
Format: epub
Tags: sustainability and environment, green design, building a home, natural building, earthship
Publisher: Rachel Preston Prinz

RUBBLE TRENCH FOUNDATION PROS

Lower cost than a concrete footing.

Uses much less concrete (production of concrete requires a great deal of energy and generates greenhouse gases).

Can use recycled crushed concrete fill.

Provides excellent drainage, and thus a "static" foundation system.

RUBBLE TRENCH FOUNDATION CHALLENGES

Soils with low bearing capacity may require an extremely wide trench (or some other footing alternative) to achieve adequate bearing area.

Not specifically addressed in Building Codes; requires additional dialog with permitting officials.

A rubble trench foundation meets the requirements and the intent of U.S. Building Codes. However, since this system is not specifically outlined in current Codes, acceptance is provided on a case-by-case basis. Since this puts permit approval at the discretion of individual building officials, it is recommended to initiate a dialog prior to submitting for a building permit. This provides an opportunity to inform and educate permitting staff and provide adequate information to satisfy their desire to ensure a safe structure. The article written by Elias Velonis for Fine Homebuilding provides excellent technical information to this end. It is recommended that stamped structural drawings be provided so the burden of proof is not purely conceptual.

My experiences with rubble trench foundations have been rather positive. I interact with the permitting office well ahead of time, and have not encountered rejection or delays. In one case the building inspector required that the structural engineer be present to verify tamping. I have needed to increase the trench width to 24 inches when a 16-inch backhoe bucket proved too difficult to find. The only impact was the need for additional gravel mix to fill the trench; even with additional gravel, the cost of the foundation was lower than a standard concrete footer would have been.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.