German to English Tech/Engineering Construction / Civil Engineering Building materials

Context:

"Isokimmstein (Grundstein zur Sockeldämmung)"

In the context of expanded clay. As far as I an ascertain, Kimmsteine are "offset bricks" (cf. "Ergänzungssteine sowie Kimmsteine in variablen Höhen komplettieren das System"/"Supplemental bricks along with offset bricks in variable heights complement the system ..." http://www.graeper.de/)

* Sentence or paragraph where the term occurs: See above
* Document type: Website
* Target audience: Builders
* Country and dialect (source): German
* Country and dialect (target): British English