GRP Tank Covers, Pit covers and Hoist Covers

Is your tank roof letting you down?

Your tank roof cover faces a double threat. Not only is steel prone to corrosion and (in time) failure, but condensation and fumes inside your tank can speed up this process.

A corroding tank roof not only risks contaminating your tank's contents, but can weaken the structure – quickly becoming a health and safety issue.

GRP fibreglass roof covers

You can avoid this, and expensive replacements, with a GRP fibreglass roof. You'll no longer have to worry about corrosion, structural instability or weathering – for many years.

We can mould fibreglass into almost any shape and customise it for almost any chemical conditions – making it the ideal material for your tank roof.

Manufactured and installed by us

Sui Generis can both manufacture and install a custom fibreglass covering, built specifically for your needs – helping you save money long term.

One of our structural engineers will create a design to your specifications, allowing for weather conditions such as wind and snow loadings. Then the appropriate resins and additives for the chemical environment will be selected, and we'll mould and assemble your new tank roof.

Best of all, we can assemble it on-site and fit it to your tank with a minimum of disruption and downtime, ensuring you get full use of your tank back fast.

Get your free tank roof survey today

Call 01206 798 798 now to arrange a free, no-obligation tank survey by one of our technical surveyors. We'll suss out your tanks and get them back in action for longer.

GRP fibreglass tank covers, pit covers & hoist covers for every need...

Fibreglass moulded tank covers Fibreglass moulded tank covers

Whatever the size or shape of your tank, we can mould and assemble a GRP roof designed specifically for it – one that won't corrode, can withstand chemical attack, harsh weather conditions and has an indefinite life expectancy.

Fibreglass moulded pit coversFibreglass moulded pit covers

Make sure your pit covers are durable enough to protect your equipment from the harshest weather conditions, while also being strong and impact resistant to keep personnel and equipment from falling in.

Airtight moulded bund coverAirtight moulded bund cover

When your bund's odour is a problem but you still need easy access, we can create an airtight bund cover from GRP fibreglass that protects your bund's contents, controls odour and has quick release, sealed hatches for easy access.

Fibreglass moulded hoist coversFibreglass moulded hoist covers

We can manufacture multi-purpose hoist covers, complete with furniture, to meet your specifications. The fibreglass hoist covers pictured above were created by Sui Generis for a Rolls Royce subsidiary and can be seen here in Barcelona Harbour.

5 good reasons to choose Sui Generis fibreglass roof mouldings...

  • Economical – lasts indefinitely
  • Strong – impact resistant
  • Flexible – copes with structural movement
  • Seamless – built watertight
  • Corrosion-proof – chemical resistant

GRP Fibreglass roof & cover guide

Tank roofs and covers protect the contents of your tanks or bunds and help ensure their structural integrity. But steel tank lids will corrode and fail over time due to harsh weather conditions, rust and chemical attack.

This can leave your tanks and their contents vulnerable and pose a health and safety risk to your staff – often resulting in expensive replacements.

However, if you replace your tank roof or cover with a new fibreglass roof from Sui Generis, you can protect the contents of your tank and avoid the problems associated with steel – indefinitely.

Read more.

We can design, build and assemble a fibreglass covering to your exact specifications and have it installed by our experts with minimum downtime for your tank.

What kinds of liquids are your tank covers suitable for?

With the right chemical resistant resins and additives, GRP roofing from Sui Generis can handle almost any liquids and chemicals, including:

  • Diesel
  • Oil
  • Chemical storage
  • Fuel oil
  • Heavy oil
  • Gas oil
  • Heating oil.

Why use a fibreglass roof?

Because unlike steel, a GRP fibreglass roof cover isn't affected by chemical attack or weathering and has an almost indefinite lifespan.

Fibreglass is also more cost-effective that traditional materials, can be moulded into almost any shape and can be made watertight.

Are there other benefits to fibreglass covers?

Yes. These are just some of the properties of GRP tank roofs:

  • Corrosion Proof
  • Chemical resistant
  • Leak free
  • Impact resistant
  • Flexible.

Can you give me advice about my tanks?

Yes, we'd be happy to help you with whatever problem your tanks face.

Just call us on 01206 798 798 today and we'll help you arrange a free site inspection of your tanks – then help you get them back in perfect working order.


  • "Sui Generis fabricated the seating beautifully...They provided us with an in-depth overview to the products on offer and case studies to show how it would work in situ. They understood what was needed and refined the seating to match our requirements. The fibreglass seating was delivered on promised production schedule and the colours were just as described with a perfect finish."

    R Peckham,
    Sui Generis fibreglass bespoke seating manufacture

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  • "Communication was good throughout the design and pre-installation stages."

    M Gaedke, Sui Generis GRP Wave Canopy

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  • "Your quotation, as always, is very competitive (but it's your professionalism and superb build quality that sells it to us!)"

    P Hawtin, Sui Generis bespoke Red Cabinet

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  • "On a personal note, I think suigeneris has some of the nicest and most polite staff I have ever dealt with in all my years of business.

    You have all been absolutely lovely and a credit to your organisation."

    D Moy, Sui Generis bespoke GRP Bund

    Read more testimonials


ISO 14001
Our accreditationsArmed Forces Silver Covenant

Sui Generis: The market leader in fibreglass mouldings

Sui Generis quality guaranteeQuality guarantee

Our highly competitive work gives you the best quality results every time – every one of our operatives is highly skilled, well trained and takes exceptional pride in what they do. With Sui Generis, you can rely on effective, long-lasting work.

About Sui Generis.

Sui Generis fully CompliantCompliance and accreditations

When you choose Sui Generis to undertake work on your behalf, it always complies with and exceeds the standards required by relevant legislation. We always advise you what the regulations require before we start.

ISO 9001:2008 and accreditations.

Sui Generis health & safety promiseOur health & safety promise

We take your safety seriously, and that of all our people, whether we're at a small factory or a nuclear plant. We always adhere to stringent health and safety procedures at every stage – and comply with your own Heath and Safety policies.

Health & Safety.

Sui Generis satisfaction assuredSatisfaction Assured

Every job we undertake is completed with your satisfaction in mind. We work hard to be the best at every task we tackle – and that's why over 90% of our customers return to us time after time.

Customer Testimonials