Properly installing your Promax water tank will give you years of trouble-free service. Selecting what you put at the base of your tank is part of that installation process, and you have options that will comfortably fit in with your budget. Whichever you choose, proper preparation is what makes it work.
Why the base is part of the warranty, not just the build
That is more than just a piece of friendly advice we are passing on to you. You must install your Promax storage tank according to our written instructions. Failure to do so will void the warranty and may result in tank failure, so we want to work with you to avoid those issues. Because base preparation sits inside the installation process, it is not a step you can improvise and still keep your cover. Our team will always be available to share their expert knowledge, and our detailed yet easy-to-read installation guide sets everything out methodically.
Sand, fine gravel and crusher dust
Sand, fine gravel or crusher dust compacts well to provide an excellent base for your tank to sit on. Materials like these are the cheapest, especially if you are installing a high-capacity tank with a large footprint, where the area you have to cover is what drives the cost. A base made from this material requires a depth of 100 millimetres. That depth is the specification rather than a starting point to negotiate down, because the depth is what allows the material to compact and spread the load the way it is there to do.
Why the base needs a retaining cover
You must use a retaining cover to stop the sand from eroding after you have installed the tank. It is the step most likely to be skipped, because at the moment of installation the base looks finished and the tank is already sitting on it. The problem arrives later. A sand, gravel or crusher dust base is loose material by nature, and loose material moves once weather gets at the edges of it. If it erodes, the tank is no longer sitting on the full base you built, and the support you paid for is quietly reduced without anyone noticing.
Partially burying an Enduro tank
Promax Enduro tanks are corrugated, which gives them enough strength to be partially buried. How deep depends on the tank size. Enduro tanks ranging in capacity from 10,000 to 30,000 litres may be buried up to one metre if you adhere to our instructions. You can partially bury our smaller Enduro tanks, too. Those ranging from 450 to 5,000 litres can be submerged to one third of the side wall height, but again, that is only if you follow our instructions. If this is your preferred method of tank installation, you can also use sand, fine gravel or crusher dust as the base, again with a depth of 100 millimetres. The ENDURO vs XPRESS comparison sets out the range.
Concrete base pads
Concrete is another recommended option for a base. This is conditional on having a smooth concrete base pad that will support a tank weight full of water without cracking or shearing. For optimum strength and durability, Promax recommends a minimum 100mm mesh reinforced concrete 20MPA. Your budget might not stretch far enough for a concrete base for one of our larger tanks, but it is worth considering for smaller models, where the area to be poured is small enough to keep the cost sensible. The condition matters as much as the material: a pad that cracks or shears is not doing the job of a base.
The weight you are actually supporting
It is worth being specific about the load. 10,000 litres of water weighs ten tonnes, so you must build a base with enough strength to handle all that weight. That figure is the reason base preparation is not a formality to be rushed. The tank is not the load. The water is, and the base is what carries it. Whatever material you choose, it is that weight, sitting in the same place permanently, that the base has to deal with without settling, cracking or shearing. Sizing the tank first helps, and what size water tank do I need walks through that.
Industrial and specialised pads
If you are installing tanks for industrial projects, get in touch with us, and we can discuss specialised pads that act as bases in these settings. Industrial sites tend to bring conditions that a residential base is not designed around, so the base is better treated as a design question than as a default. The principle does not change: whatever sits under the tank has to carry a full tank permanently, without moving. What changes is how much engineering goes into establishing what that takes on your particular site. Our industrial sector page is the place to start.
Follow the installation guide
Regardless of your situation, be it residential, commercial or industrial, you need to follow the installation instructions to the letter. No shortcuts. The instructions exist because the base, the warranty and the working life of the tank are all the same subject, and the difference between a base that works and one that fails is usually a step somebody decided was optional. Read the guide before you order the material, not after it arrives. You will find the current guides on our downloads page, and do not hesitate to contact our team for further advice. We are here to make your tank installation smooth and easy, from the base upwards.
Call Promax on 0800 77 66 29.