Commercial floor preparation is the moisture testing, grinding, patching, levelling and remediation of a slab before flooring is installed. Premrest Flooring treats substrate preparation as a separate, documented discipline on every commercial project across Melbourne, Sydney and Brisbane because substrate failure is the number one cause of flooring failure.
Built for programs, not one-offs
- Head contractors delivering new-build commercial floors
- Property teams replacing failed vinyl, carpet or resilient flooring
- Project managers on refurbishments where existing substrate is unknown
- Developers handing over base-build tenancies
- Facilities teams investigating recurring flooring failures
Our process
Moisture testing to AS 1884
In-situ relative humidity probes read at 72 hours, documented and shared with the head contractor before adhesive is specified.
Grinding & patching
Diamond grinding to remove residues, curing compounds and high spots, then patching to fill defects.
Self-levelling
Pump-applied or hand-applied self-level compounds to bring the slab to tolerance for the specified floor covering.
Moisture remediation
Two-part epoxy moisture barriers where slab RH exceeds the adhesive threshold, documented and warranted.
Why substrate failure is the number one cause of flooring failure
Adhesive bond, seam weld integrity, sheet flatness and topcoat performance all depend on a compliant substrate. When vinyl bubbles, carpet tile lifts or LVT curls, the trigger is almost always moisture, contamination or an out-of-tolerance slab. Fixing it after handover means uplifting the floor, re-prepping the slab and reinstalling. Doing it correctly upfront is faster, cheaper and warrantable.
Moisture testing done to a published standard
We test to AS 1884 using in-situ relative humidity probes drilled into the slab and read at 72 hours. Results are photographed, dated and shared with the head contractor. Where the reading exceeds the adhesive manufacturer's threshold, we specify a two-part epoxy moisture barrier and re-test before proceeding. We do not rely on surface moisture meters as a compliance test.
Grinding, patching and levelling
Diamond grinding removes residual adhesive, curing compounds, laitance and high spots. Patching handles cracks, drummy sections and small defects. Self-levelling compound is pump or hand applied to bring the slab within tolerance for the specified floor covering, typically ±3mm over 3m for sheet vinyl and LVT.
What you get on handover
A written prep ITP with photos, moisture test results, product data sheets for compounds used, and confirmation the substrate meets the flooring manufacturer's specification. It becomes part of the floor covering warranty pack.
Where this service lands
Common questions
Why does floor preparation cost so much?
Prep is variable by slab condition and typically drives a large portion of the flooring line on refurbishments. When existing substrate is unknown, we recommend a small investigative works stage before committing to a fixed price so the head contractor sees the true condition.
How do you test slab moisture?
We use in-situ relative humidity probes drilled into the slab and read at 72 hours in accordance with AS 1884, then share dated photos of each probe reading with the head contractor. Surface moisture meters are indicative only and not used as a compliance test.
What happens if the slab is too wet?
We apply a two-part epoxy moisture barrier rated to the reading, then re-test above the barrier before installing floor coverings. The remediation is documented and warranted so the flooring warranty stays intact.
Can you fix a failed flooring installation?
Yes. We diagnose the failure back to substrate condition, uplift the affected area, re-prep the slab correctly and reinstall to the original specification with full documentation.
Available across our three cities
Service project?
Let's talk.
Tell us about the project and we'll send our capability statement within one business day.