A tank cover does quiet, essential work — and aluminum is purpose-built for it: corrosion-free in an aggressive headspace, light enough to span and to retrofit, and engineered to land on whatever tank you're building or already own.
01 Why aluminum for liquid storage
The case for aluminum starts with the environment a cover lives in — warm, wet, and often loaded with corrosive vapors like hydrogen sulfide. Aluminum answers it on every front:
- Corrosion resistance. Aluminum forms a tight, self-renewing oxide layer that shrugs off the humid, chemically aggressive headspace above stored liquid. There is no coating to recoat — unlike a steel roof, which trades its protection the day its paint fails.
- Lightweight. At roughly one-third the weight of steel, an aluminum cover imposes a fraction of the dead load on the shell and foundation. That's what makes a clear-span dome possible — and a retrofit possible without reinforcing the structure underneath.
- Clear-span capability. A structurally supported aluminum dome carries itself with no internal columns, leaving the entire interior open for mixing, aeration, and access.
- Low maintenance, long life. No recoating cycles, no rot, no spalling — aluminum covers routinely serve for decades with minimal upkeep.
- Fast, retrofittable erection. Lightweight components assemble quickly, and a dome can often be built and raised over an existing tank — sometimes while it stays in service.
02 Aluminum geodesic domes
The aluminum geodesic dome is the workhorse fixed roof: a triangulated space frame of 6061-T6 struts and gusset hubs, closed by batten-sealed aluminum panels, mounting to the tank's top perimeter. It is self-supporting and clear-span — no posts in the liquid — and it scales to very large diameters, well over 300 feet.
Domes are engineered to the governing standards for the service — AWWA D108 for water storage tanks and API 650 Annex G for petroleum and many industrial tanks — with panel, strut, and connection design carried out to the Aluminum Design Manual for the project's wind, snow, and seismic loads.
What a dome delivers: a permanent weather barrier that keeps rain, snow, debris, and birds out; vapor containment for odor and emission control; and a corrosion-free roof that won't become tomorrow's recoating or replacement project. Typical duties span potable water reservoirs, wastewater clarifiers and basins, and petroleum and chemical storage.
Aluminum domes well over 300 ft in diameter — and no internal columns.
03 Aluminum internal floating covers
Where a dome sits above the liquid, an internal floating cover rides directly on the liquid surface, rising and falling with the level. Built from aluminum pontoon or full-contact honeycomb panels with a peripheral seal against the shell, it attacks a different set of problems:
- Evaporation control — a floating cover dramatically cuts evaporative loss of water or product.
- Emission and odor control — by minimizing the vapor space, it reduces VOC and odor release.
- Water quality — blocking light suppresses algae growth and protects against airborne contamination.
Internal floating covers are frequently paired with a fixed roof or dome above for a complete, two-layer system: the dome keeps the weather out, the floating cover keeps the vapor space — and evaporation — down. They are designed to the principles of API 650 Annex H for internal floating roofs where applicable.
04 Cover accessories
A cover is a system, not just a roof, and the accessories are what make it perform and stay serviceable. TanksandCovers supplies the full complement for any configuration:
- Venting — pressure/vacuum vents, gooseneck and mushroom vents sized to the tank's fill/draw and thermal breathing.
- Access — manways, hatches, gauge hatches, and access doors.
- Sealing — peripheral seals, batten and gasket systems, and perimeter angles.
- Safety — handrails, fall protection, and code-compliant walkways.
- Flat and launder covers — aluminum flat-panel covers for troughs, weirs, channels, and rectangular basins where a dome doesn't apply — ideal for odor capture and debris exclusion.
These pieces integrate into domes, floating covers, and open tanks alike, so a tank gets exactly the venting, access, and sealing its service requires.
05 Choosing the right cover
| Aluminum Geodesic Dome | Internal Floating Cover | Cover Accessories | |
|---|---|---|---|
| Where it sits | Clear-span fixed roof on the shell, above the liquid | Floats directly on the liquid surface, inside the tank | Integrated into domes, covers, and open tanks |
| Primary function | Weather barrier, vapor containment, clear-span access | Cut evaporation, emissions, odor, and light/algae | Venting, access, sealing, and fall protection |
| What it solves | Open-top exposure, debris/bird intrusion, corroding steel or concrete roofs | Evaporative loss, VOC/odor emissions, algae growth, product quality | Breathing, gauging, access, peripheral sealing, safety |
| Applications | Potable water, wastewater basins, petroleum, chemical | Potable and process water, fuels and solvents, odor control | All of the above |
| Tank types | Concrete · welded · bolted | Concrete · welded · bolted | Concrete · welded · bolted |
The dome and the floating cover aren't competitors — they solve different problems, and many tanks use both.
06 Built for any tank — new builds and replacements
Aluminum covers are engineered to land on whatever you're building or already own — concrete, welded steel, or bolted steel — with the perimeter attachment detailed to the shell type.
- New builds. The cover is designed into the tank from the start, with the shell top, anchorage, and loads coordinated up front.
- Replacements. This is where aluminum's light weight pays off most. A deteriorating concrete roof — spalling, leaking, shedding into the water — or a corroded steel roof can be replaced with an aluminum dome the existing shell and foundation carry without reinforcement. Because a dome can frequently be assembled and raised over the tank, downtime is minimized, and in many cases the tank stays in service through the changeover.
From clear-span geodesic domes spanning well over 300 feet, to internal floating covers that cut evaporation and emissions, to the vents, hatches, seals, and flat covers that make a cover a finished system — aluminum does it without the corrosion, weight, and maintenance burden of steel or concrete.
On concrete, welded, or bolted tanks, new or existing, TanksandCovers.com has the coverage your project needs.