Talk to any Mackay pool builder about the Northern Beaches and you’ll hear the same story: gorgeous blocks, gorgeous outlook, terrible pool sites. The land runs down to the water, the backyard slopes 3–5 metres across its length, and standard “dig-a-hole” fibreglass installation isn’t practical without massive retaining works.
Compass developed Maxi Rib specifically for these blocks. It’s the technology behind our Bailey install at Dolphin Heads (a full cliff-edge above-ground build) and the Hope install at Eimeo (a semi-raised deck-level configuration). Here’s how it actually works.
What Maxi Rib is
Standard fibreglass pool construction relies entirely on the shell itself to hold water. That works fine when the pool sits fully in the ground, surrounded by backfill that supports the walls under the water pressure. It doesn’t work when part of the shell needs to sit above ground with no earth around it.
Maxi Rib is a set of structural ribs laminated to the outside of the shell during factory manufacture. On site, those ribs get filled with reinforced concrete during installation. The result: the shell can carry its own water load structurally, without needing surrounding earth for support. That’s what lets Compass build full-size pools that are freestanding, partially raised, or built into a cliff face.
Three install modes
Fully in-ground with Maxi Rib
Even on flat blocks, some Mackay families spec Maxi Rib for the extra structural stiffness — particularly on reactive-soil sites where the ground moves seasonally between wet and dry. It’s cheap insurance against long-term movement.
Semi-above-ground
Half the shell sits above finished ground level. This is what the Hope family install at Eimeo looks like — a raised deck runs along one side of the pool, with the shell tucked into the natural fall of the block. Aesthetically it reads as a pool integrated with the landscape rather than punched into it. Practically, it dramatically reduces earthworks costs.
Fully above-ground
The whole shell sits above the finished ground line. The Bailey install at Dolphin Heads is the coastal example — a full 7m Sanctuary Maxi Rib overlooking the Coral Sea, built without excavation into what was previously an unbuildable clifftop position. The pool is engineered, the surrounding decking is engineered, and the whole assembly carries its own load.
Where it pays off in Mackay
The Mackay region has more Maxi-Rib-suitable blocks than most people realise. Northern Beaches ridgelines (Eimeo, Dolphin Heads, Blacks Beach). Andergrove and Beaconsfield split-levels. Rural Marian and Walkerston blocks with rocky ground that makes excavation expensive. Collinsville hillside builds. On any block where the fall is greater than about 1.5 metres over the pool footprint, Maxi Rib is worth costing against a traditional in-ground install.
What it costs vs the alternatives
Maxi Rib typically adds $12,000–$25,000 to a standard in-ground installation, depending on how much of the shell is above ground and how much decking or structural sign-off it needs. That’s a real number. But it’s substantially less than:
- Concrete pool alternative on the same site ($30,000–$70,000+ more, plus longer build time)
- Retaining works to force a level pad on a sloping block ($25,000–$60,000 for engineered walls at real Mackay quotes)
- Bringing in fill to raise the low side (often more than the retaining option once you factor drainage and compaction)
In every hillside site we’ve costed both ways, Maxi Rib has come in cheaper than the alternative in-ground install.
Does it change the warranty or features?
No compromises. Above-ground Compass pools carry the same Ceramic Core construction, Bi-Luminite colour range, Vantage self-cleaning option, and lifetime structural warranty as any in-ground install. Maxi Rib is a construction method, not a compromise on the product.
How to know if your block needs it
Best answer: free site visit. Luke will walk the block with you, measure the fall properly, look at access for the truck and crane, check soil conditions, and give you an honest recommendation — including whether Maxi Rib is genuinely necessary or whether a standard in-ground install will do the job for less.
