Not all walls are equal — some can be built twice as fast, in all weather conditions, while delivering all the strength and durability required by New Zealand’s stringent building requirements.
This sounds like a job for Structural Formblock, according to W Stevenson & Sons Ltd building products technologist Ryan de Kock.
“The fastest way to lay blocks, Formblock lets you construct certain structural walls quickly, accurately and efficiently. It’s a unique masonry system stacked with benefits,” he says.
“Construction of a wall is around twice as fast as conventional blockwork for large, low-complexity walls, and can be done even when it rains or when blocks are wet,” he says.
Mr De Kock says Formblock is ideally suited for sizable, simple walls that need to be constructed quickly, such as inter-tenancy, retaining, basement and boundary walls, and a competitive alternative to precast and timber frame construction.
Conventional mortar is used only to level the first course, so subsequent courses can be laid in all weather conditions.
A Formblock wall is designed the same as a standard block wall, except for a slightly different starter bar layout.
The builder stacks the blocks and clips them together with a bridge in a stretcher bond pattern, places the steel rods, then fills the wall with a specially designed Stevenson Formfill concrete mix to maintain the system’s performance.
He says as with standard masonry, the walls need control joints to reduce stresses that can cause cracking. In addition, Formblock nominal block sizes allow conventional blocks such as lintels and rebated blocks to be mortared into a Formblock wall.
This sizing also allows Formblock to be dovetailed into a conventional existing masonry wall.
Mr De Kock says a new area of masonry design which suits Formblock well is post-tensioning, a form of construction designed to improve structural performance of walls for certain applications.
Stevensons DryBlock technology can be used simultaneously with Formblock as a made-to-order product to improve weatherproofing.
When the wall is ready, exterior surfaces can be plastered or clad, and interior surfaces lined, plastered or left exposed.