To increase the size, you’d have to build the new mould around the existing and pour new concrete around it, using either the craft mix or worktop premix. Each surface where the new concrete meets the old would need to be primed using our universal primer.
In either case, you would then have to go over the entire piece with microcement because there would always be a line where the new mix meets the existing concrete.
This is a slightly more complex type of project but still well within the capability of a newbie to concrete!
Pic 1 – existing tabletop made too small
Pic 2 – new mould built around existing
Pic 3 – new concrete poured into mould
Pic 4 – mould removed/stripped
Pic 5 – New increased size concrete flipped over, ready to be microcemented.