Greenblock Fixed-Web blocks come in two core widths: 6"and 8". Considered the backbone of the Greenblock product line, our fixed-web systems have been designed to provide buiders with a tough,tested and proven wall system requiring minimal bracing with no costly, time-consuming secondary operations such as gluing, strapping or taping. This versatile system , like all Greenblock products, incorporates many design features which continue to make it the most copied ICF block in the industry. Here are 3 fundamental features built into all of our blocks: 1. A true flat-wall system; allows for better concrete distribution inside the wall, minimizing the possibility of voids and "honeycombing". 2. Sub-surface web ties on 6 inch centers; creates a much stronger block than those with ties on 8" centers or greater. Wavy walls and "blowouts" are virtually eliminated and higher pour heights are easily achievable, saving time and money. 3. Lego-like attachments allow each block to lock together, eliminating the need to glue or strap the product like other systems on the market. Our patented "nub" system eliminates lifting or shifting during the pour. Once constructed a Greenblock wall is stronger, straighter and safer than a stick built wall. Go to our "Fixed Web spec sheet" for further product details