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Homemade Insulating Concrete

By Will Gish
Always check your local building codes before pouring concrete.
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Each building material comes with advantages and drawbacks. Concrete, for instance, possess extreme strength and fire-resistant qualities, but lacks insulating value. However, methods of making insulated, or insulating, concrete exist. Using these methods in and around the home gives you a building material of exemplary strength and high R-value, or insulating ability. Various methods of making insulating concrete exist, including DIY concrete insulating forms and insulating prefabricated materials like concrete blocks.

Insulating Concrete Basics

Two types of insulating concrete exist: an actual concrete aggregate with insulating additives and concrete poured into, around or otherwise combined with a separate, insulting material, usually some kind of insulating foam. Builders use the former material just like standard concrete, pouring it and allowing it to set as is. The latter material constitutes a combination of two materials that raises the insulating value of the concrete while drastically increasing the strength of the foam.

Making Concrete

You can make homemade insulating concrete with foam forms by purchasing each of these materials and combining them or by making your own concrete and insulating foam forms. When it comes to homemade insulating aggregate, you can either purchase wet concrete and add the aggregate or make everything from scratch. Making concrete requires mixing cement or mortar with water and an aggregate like sand, crushed stones, slag, gravel, or something similar. You can purchase raw materials for concrete from a construction supply or hardware store. To make insulating concrete, add perlite or pumice along with, or instead of, the aggregate.

Insulating Forms

Insulating forms look like large foam bricks with hollow centers. After assembling a structure from them, you pour concrete in the hollow center and allow it to dry. As the concrete dries, it hardens and combines with the foam forms to create a single surface. A basic insulating form consists of little more than two pieces of foam held together by small plastic rods. You can make these forms at home by purchasing large quantities of insulating foam, cutting the foam to uniformly sized boards and sticking the boards together with plastic rods. Look at some photos of commercially available forms to get ideas for form size and construction.

Other Methods

Various other DIY methods for creating insulating concrete exist. For instance, you can purchase standard concrete blocks and fill the holes in these blocks with foam insulation. This transforms the standard concrete building block into an insulated block. You can purchase blocks of foam insulating material and coat them in layers of concrete, creating a single block with the properties of both materials. You can use foam-filled concrete blocks and concrete-coated foam blocks in the same manner as you would use standard concrete blocks.


About the Author


Will Gish slipped into itinerancy and writing in 2005. His work can be found on various websites. He is the primary entertainment writer for "College Gentleman" magazine and contributes content to various other music and film websites. Gish has a Bachelor of Arts in art history from University of Massachusetts, Amherst.