Like many other successful ideas, no-fines construction is very simple in basic concept. No-fines concrete is a mix containing only carefully graded clean aggregate approximately 3/4 to 3/8 inch in size and Portland cement. These are combined at rates of one part of cement with 8 to 10 parts of aggregate. No fine material either sand or gravel is included. Such mixtures produce an open textured cellular concrete with a high volume of voids and good insulating properties. The U-value for an external 10-inch wall with an internal dry lining is 0.20 Btu per hour square foot degree F. The mix is lighter than normal weight concrete and it is very strong; walls made with it are loadbearing. Fresh no-fines concrete compacts well inside formwork under its own weight and needs no mechanical compaction.


The rough-textured face of the no-fines wall provides an excellent surface for plastering; the standard exterior finish is dry dashing, using a variety of color dashings on a two-coat plaster of sand-lime-cement. Other exterior treatments can be incorporated, including tile-hung, weatherboarded, paneled (inserts for attaching are cast into the wall), and brick. Interior finishes depend on clients' specifications, but the most commonly used are: wet plastering, with a layer of expanded polystyrene incorporated to increase thermal insulation; dry lining with plasterboard backed up by a layer of expanded polystyrene attached to the wall; and freestanding dry lining of story-height, paper-faced, cored plasterboard panels with taped joints or skim-coated with plaster, the boards being fixed at top and bottom only.