Diamond Joint Sealers
Customers who'd hit dead ends elsewhere found this team willing — and the result was clean work at an affordable price.
That said, all three customers landed on the same two points independently: the work was done cleanly and the price didn't sting — and at least one customer found Diamond Joint Sealers after failing to track down anyone else willing to take on the job. For homeowners dealing with a waterproofing or joint-sealing problem that other trades have passed on, that pattern is worth noting. Before booking, ask them directly about your specific substrate or joint type to confirm it's within their wheelhouse.
Their work
What it's like working with them
Based on a sample of Google reviews (3 total)
“struggling to figure out people who would fix”
“affordable and clean work done”
What they help with
Based on what their customers hired them for
How they stack up
Context from 142 waterproofings in Parramatta
Credentials & background
Sourced from 3 public records so you don't have to look them up yourself
About Diamond Joint Sealers
Running for roughly a dozen years out of Mays Hill, Diamond Joint Sealers focuses on waterproofing work where the details matter — sealing joints, preventing water ingress, and finishing jobs cleanly enough that customers comment on the tidiness of the result. The business name points to a specific niche: joint sealing is a technically precise discipline distinct from broad waterproofing membrane application, typically applied to concrete structures, balconies, wet areas, and expansion joints where movement or penetration is the root problem. Reviews mention affordable pricing alongside clean workmanship, which suggests the business pitches itself to homeowners who've already had trouble finding someone willing to take on these kinds of targeted, fiddly jobs — not large-scale remediation contractors. The feedback consistently flags that the team was easy to engage after customers had struggled to find anyone else willing to help, pointing to a niche that suits tricky or overlooked waterproofing problems rather than straightforward new-build installs. No individual staff names appear in the reviews, so it isn't possible to map team members to specific tasks, but the work quality and site cleanliness are what customers call out directly.
Best for: hard-to-place joint sealing and waterproofing jobs that other trades have declined, homeowners seeking a neat finish at a reasonable price point, and targeted water ingress repairs on concrete or masonry.
Location
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Claim This Profile — Free →Common questions about Diamond Joint Sealers
What kind of waterproofing work does Diamond Joint Sealers specialise in?+
The business name and reviews point to joint sealing as their core focus — addressing water penetration at expansion joints, control joints, and similar junctions in concrete or masonry structures. This is distinct from broad membrane waterproofing applied to whole surfaces. Customers have mentioned them specifically for jobs that were hard to get other trades to take on, suggesting they handle targeted or technically specific waterproofing problems. For large-scale membrane work on new builds, confirm with them directly whether that falls within their scope.
What do customers say about pricing?+
One reviewer specifically calls out the work as 'affordable,' which is notable in a trade where specialist sealing jobs can attract premium quotes. The same review also praises the quality of the finish, suggesting the pricing doesn't come at the expense of the result. There are only 3 reviews total, so this is a limited data point — but none of the three raise any pricing concerns. It's worth getting a quote and comparing before committing.
Is Diamond Joint Sealers suited to residential jobs, or do they focus on commercial work?+
The reviews don't distinguish clearly between residential and commercial projects, and no reviewer describes a large-scale commercial site. The nature of the feedback — individual homeowners finding them after struggling to locate a tradesperson — leans residential. That said, joint sealing is used across both sectors, so contacting them with your specific project type is the best way to confirm fit.
How does the team handle site cleanliness after the job?+
Site cleanliness is one of the two things customers mention unprompted — one review specifically calls out 'clean work done' as a reason to recommend the business. For waterproofing and sealing jobs, which can involve messy sealant compounds, this is a practical plus worth noting. With only 3 reviews available, it's not possible to call this a universal guarantee, but no reviewer raises any concerns about mess or workmanship.
What areas does Diamond Joint Sealers service?+
The business is based in Mays Hill, NSW, in Sydney's western suburbs. Reviews don't specify how far they travel for jobs, and there's no mention of a defined service radius. If you're located further from the Mays Hill area, it's worth confirming whether they cover your suburb before arranging a quote.