There are different dimensions of concrete blocks depending on its use. Main blocks used for walls are called stretchers and are 190 x 390 x 190. Knockouts are blocks that are the same dimensions but are placed under a window sill. Above the knockouts are half height blocks that are 190 x 390 x 90. Sill blocks are just below the window but are not actually square. The have five dimensions
. because they are contoured to fit the window frame. There are also half blocks that are 190 x 190 x 190 and half height halfs that are 190 x 190 x 90. Get more information at www.blocklayer.com.
