Perlite Roundhouses

A reader asked if perlite is a good choice for building earthbag roundhouses. Perlite should work if you make some adaptations. It has excellent R-value and so, in my opinion, is well worth a little extra effort. In fact, it’s a top choice because of its R-value of 2.7 per inch. So 15″ would give … Read more

Vetiver/Lime and Vetiver/Clay

There’s growing interest in lightweight bag fill materials as alternatives to more labor intensive soil-filled earthbags. While lightweight materials such as scoria, perlite, etc. are not as stable as tamped earth, their higher insulation value and labor saving advantages offer tantalizing possibilities for certain designs, locales and site conditions. We’re currently investigating vetiver grass as … Read more

Earthbag/Stone Foundations

The most recent issue of The Last Straw journal (#60) has my article about earthbag/stone foundations. The following information is just a short excerpt. You can buy the full length article from The Last Straw. The design outlined here can be used with load-bearing and non load-bearing straw bale walls, earthbag walls, cob, adobe, cordwood … Read more

Insulated Earthbag/Geotextile Basement Walls

This article describes a low cost method of building insulated basement walls without concrete, using geotextiles. Typical basement walls are expensive and use large amounts of concrete, a major contributor to global climate change. Concrete basement walls are typically built by contractors, because they require expensive forms and specialized knowledge. Plus, in cold climates they … Read more

Using Scoria for Earthbag Building

If you’ve been reading our blogs and websites, you’ll often see reference to scoria. Scoria, also known as lava rock, has numerous properties which make it a great building material. The key breakthrough for earthbag building was Kelly Hart’s house made with bags of scoria. His house stays comfortable year round in a very cold … Read more

Woodchip/Light Clay Earthbags

Woodchip/light clay is a traditional building material in Germany and other European countries. It’s typically used as infill between timbers in post and beam construction. I’ve been told that bags of pre-mixed materials are standard items in building supply centers, and blocks can be made to order. The drying time, shrinkage and labor are less … Read more