Wash up after the blockwork has been filled with concrete

Filling the Blockwork

Monday June 15

Fill it up

The blockwork is to retain the fill beneath the concrete slab so the blocks needed to be filled with concrete.  This is known as ‘core-filled’ blockwork and is used when a blockwork wall will be retaining something, such as fill (in this instance) or earth (in a retaining wall). We had to first wait a couple of days for the mortar between the blocks to set. Greg had made a useful little jig that acts like a funnel – it fits over the top of the blocks and slides along as you shovel the concrete in. We didn’t need a concrete pump truck for this job because it didn’t take much concrete to fill the blocks – just a couple of wheelbarrows being pushed back and forth.


Greg filling the blocks with concrete

Greg filling the blocks with concrete

Knock it off

The top course of blocks is known as ‘knock-out’ blocks – the back and the sides of the block get knocked out after the concrete fill has set, leaving the front face to form the edge of the concrete slab. This edge could instead be formed with timber but we chose to use knock-out blocks because it would be easier (laid at the same time as the blocks below) and conceals the edge of the concrete slab behind the block (otherwise you would see the slab above the blockwork).


The top course of 'knock out' blocks, with the corner block already knocked off

The top course of ‘knock out’ blocks, with the corner block already knocked off. The timber peg with the nail is the level for the floor


Costs: concrete – $313


Disclaimer: Any advice contained within this blog is of a general nature only and cannot be relied upon. Details provided are in good faith and relate specifically to this project. Any author will not be held responsible for advice or information presented.

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