Dowel Hole Coring, Slab Saw Cutting and Pockets, Mortdale NSW

The job

CIP Constructions is building a new multi level building on Blackshaw Avenue in Mortdale. Through the structure and into the fit out, the job needed a concrete cutter at a lot of different stages: dowel holes for the precast panels, slabs cut and broken out, and pockets, rebates and chases cut to set out for the trades that followed.

Perfect Concrete Care did that work for CIP in staged visits from April 2025 to February 2026. Each visit was booked when an area was ready, and each one finished with the site diary signed by CIP's supervisor.

What the work involved

• Core drilling dowel holes, 28 mm diameter and up to 500 mm deep, along the slab edges on the eastern side for the precast panel install. On the busiest days in April 2025 the crew drilled between 25 and 38 holes a day
• Saw cutting the slab with a road saw at depths from 60 to 200 mm, with more than 130 lineal metres cut at 200 mm on a single day in August 2025
• Cutting and breaking out slab edges and ramps, and cutting pockets into the slab with a demo saw and chaser, then breaking them out with a jackhammer
• Cutting rebates and pockets around cast in bolts and fixing plates to the set out marked by the builder
• Concrete scanning ahead of cutting where CIP wanted reinforcement, post tensioned cables and slab thickness checked
• Chasing floors and walls in the fit out, including a long chase along a ground floor sill in February 2026

What made it hard

The dowel holes came first and they had to be right. Every hole had to be in its marked position and drilled to depth, because the precast panels were coming and the bars had to land where the panels needed them. Early on there was no site power at the eastern edge, so the crew ran the drills off two generators.

Later in the job the work was all about cutting to someone else's set out on a slab that was staying. Pockets and rebates had to be square, to size and in the right place, often around cast in bolts that could not be damaged, and a few visits were held up while the rebates were marked out or the rain passed.

How it was done

The dowel holes were drilled wet with the slurry on a wet vac, and every hole was checked for depth with a tape before the bars went in. The slab cuts were done with a road saw, wet, with the slurry vacuumed as the saw went, so the slab stayed clean for the next trade.

Pockets and rebates were cut with a demo saw, ring saw or chaser to the marked outline, then broken out inside the cuts with a jackhammer, so the edges stayed straight and the slab around them was not damaged. Where cast in bolts were in the way, the pocket was cut around them.

Lessons learned on this job

Every job teaches the crew something. These are the ones from Mortdale that we take onto every coring and cutting package.

What worked

• Check every dowel hole. A tape in every hole before the bar goes in means no surprises when the precast arrives
• Cut first, break second. Saw cutting the outline before the jackhammer goes in keeps pocket edges square and stops the slab cracking past the line
• Wet cutting with a vacuum. Picking up the slurry as the saw goes leaves the slab clean enough for the next trade to start straight away
• Write it all down on the day. Hole counts, sizes, depths and metres cut on the signed diary every visit kept the record clear for both sides

What was difficult

• No power at the work face. Running drills off generators works, but agree where site power will be before the crew arrives
• Waiting on set out. A cutter on site with nothing marked is lost time, so pockets and rebates need to be marked before the booking
• Cast in items in the way. Bolts and plates already in the slab need to be shown on the mark up so the cut can go around them
• Weather on an open slab. Rain stops road sawing on an exposed slab, so outdoor cutting is best booked with a weather check

How it went

Across staged visits from April 2025 to February 2026, the dowel holes were drilled for the precast, the slabs were cut and broken out where the drawings called for it, and the pockets, rebates and chases were cut to set out for the trades that followed.

If you have something similar

Builders need dowel holes, slab cuts and pockets done to the set out, when each area is ready. Have a look at our concrete core drilling Sydney, concrete cutting Sydney and concrete scanning Sydney pages, or get in touch.