GDM Pools - Concrete Pool Renovations
Gil has reversed other contractors' wrong diagnoses on multiple occasions — and customers keep coming back for years afterward.
From the 50 reviews we analysed, Alex's maintenance service stands out as a genuine ongoing relationship: he visits regularly, leaves a written chemical and service report each time, and customers describe pool quality improving noticeably compared to previous providers. The family-business structure means Gil, Rhys, and Alex are the consistent faces on every job rather than rotating subcontractors, which matters when you're handing over a significant renovation. One reviewer raised a concern about salt quality used during a post-renovation startup and felt Gil was dismissive when they raised it — that's a single isolated mention in 85 reviews, but worth raising directly with Gil if post-renovation chemical startup is part of your scope. Ask upfront who specifically will be on site for your job and what the handover process looks like if issues emerge after completion.
Their work
What it's like working with them
Based on a sample of Google reviews (85 total)
“patiently and persistently worked through issues that other pool companies put in the too hard basket”
What they help with
Based on what their customers hired them for
How they stack up
Context from 163 pool builders in Northern Beaches
Credentials & background
Sourced from 5 public records so you don't have to look them up yourself
About GDM Pools - Concrete Pool Renovations
Gil Mariani leads this Northern Beaches family operation alongside sons Rhys and Alex, and the three of them handle meaningfully different parts of a job: Gil brings deep engineering and diagnostic experience — customers specifically credit him with solving leaks and equipment failures that other companies gave up on — while Rhys co-manages renovation planning and quoting, and Alex runs ongoing maintenance rounds, delivering written pool reports after each visit. Their core work is concrete pool renovation (resurfacing tired pebblecrete pools, replumbing equipment rooms, installing new surfaces and coping), but a substantial slice of their workload is equipment-only: heat pump selection and installation, variable-speed inverter pump systems, chlorinator upgrades, filter replacements, and backwash systems. What separates them from a standard renovation company is the willingness to stay involved long after handover — multiple customers describe multi-year ongoing maintenance relationships that started with a one-off renovation. They're particularly well-suited to complex or previously misdiagnosed problems: several reviews describe Gil correctly overturning a prior contractor's diagnosis and fixing a difficult leak or equipment fault in circumstances others found impractical. Quotes are consistently described as more itemised and analytically detailed than competitors, which customers say proved to be an early signal of how the job itself would be managed.
Best for: full concrete pool renovations where you want one team managing the entire project, complex leak or equipment faults that a previous contractor misdiagnosed, heat pump and filtration system upgrades with ongoing maintenance built in afterward.
Location
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Claim This Profile — Free →Common questions about GDM Pools - Concrete Pool Renovations
Who will actually show up to my job — a subcontractor or someone from the GDM team?+
Based on consistent review evidence across more than four years, Gil, Rhys, and Alex are the people who appear on site — there's no pattern of subcontracted labour in the reviews. Gil typically handles diagnostic work, complex repairs, and renovation oversight; Rhys co-manages quoting and project planning; and Alex runs regular maintenance rounds. That said, confirm this directly when you book, particularly for larger renovation projects where site coordination is important.
Does GDM Pools handle ongoing maintenance, or just one-off renovation work?+
They do both, and several customers describe starting with a renovation and then moving to an ongoing maintenance arrangement with Alex handling regular visits. Alex leaves a written pool report after each service visit detailing chemical levels and work completed, which customers specifically mention as useful for tracking pool health. If you want a single contractor to handle the renovation and then maintain the pool afterward, this appears to be a model they actively support.
What do customers say about GDM's pricing compared to other pool companies?+
Multiple reviewers note that GDM's quotes came in lower than competitors — one customer specifically said the quote was 'many thousands cheaper than any of the others I received' without any corresponding drop in quality. The detailed, itemised nature of their quotes is frequently mentioned as making it easier to compare against other bids. For equipment installations specifically, customers describe pricing as 'very reasonable' and 'fair', though as with any renovation, confirm your full scope is captured in writing before work begins.
Can GDM Pools handle a pool problem that another contractor has already looked at and couldn't fix?+
This is a genuine pattern in their reviews — several customers came to GDM specifically after another company either misdiagnosed the problem or put it in the 'too hard basket'. Gil is credited in multiple reviews with correctly identifying that a prior diagnosis was wrong and then resolving the underlying issue, including difficult leak repairs and equipment faults. If you've already had one unsuccessful attempt at a repair, this is a reasonable business to call for a second opinion.
How responsive is GDM Pools for urgent or time-sensitive pool problems?+
Customers describe same-day or next-day responses in several reviews, including a Christmas Eve callout so the pool was usable over the holiday break, and a public holiday response that involved two to three hours of on-site work. One reviewer also noted that when a heat pump motherboard failed, Gil arrived within a couple of hours to assess the fault. Response times obviously depend on their current workload, so it's worth calling directly rather than relying solely on online enquiry for urgent situations.