What a demolition contractor needs from you before they can price a plant

Most requests to price a processing plant demolition arrive with about a quarter of the information needed to price it properly. Some photographs, an aerial with areas circled on it, a line saying the plant is redundant, and a date.

A contractor can produce a number from that. What they cannot do is produce a number that will survive contact with the plant. Everything unknown gets covered by a contingency, or it gets ignored and turns up later as a variation. Either way the owner pays for it, and the second way is more expensive and far more argumentative.

This is the list we work through before we price a plant. It is written for asset owners, closure managers and the consultants advising them. If you send this information out with your enquiry, you will get better prices from better contractors, and you will be able to compare them against each other.

Why the cheapest tender is usually the one that read the least

On a plant demolition, the structural work is rarely the expensive part. The expensive parts are the hazardous material, the decontamination, the isolations, the waste classification and the programme risk. Those are exactly the items a contractor cannot see in a photograph.

So when one price comes in well under the others, the first question is not whether they are efficient. It is what they have assumed. A contractor who has assumed the tanks arrive empty, clean and air gapped will always beat one who has priced to find out. When the tanks turn out to be neither, the cheap price becomes the expensive one and the programme goes out the window.

Giving every bidder the same complete information is the only way to get prices that mean anything.

The plant itself: dimensions, weights and materials

• Dimensions and weights of every item of plant and equipment: tanks, vessels, reactors, mills, crushers, screens, thickeners, conveyors, bins, structures. Weight decides the crane, the machine and the transport.
• The materials breakdown: steel against concrete against non-ferrous. This decides the disposal streams and the recovery value, and the two do not move in the same direction.
• The thickest steel section on the site and how high it sits: this one item sets the shear size, the shear sets the machine size, and the machine size sets what we have to float in. On a remote site that single number can move the price more than anything else on the list.
• Structural drawings, or at least general arrangements: not for aesthetics. Load paths change as soon as you start removing things, and an engineer needs to look at the sequence before it is priced.
• Foundations and what is under the slab: whether the concrete is in scope at all, and where the battery limit sits. Slab level up is a very different job from taking out plinths and footings.

The process envelope: what has been through it

This is the part that gets skipped and the part that matters most.

• What chemicals are in the plant now, and what has been through it historically: not just the current product. A plant that changed process thirty years ago still carries the residue of what it used to do.
• Decommissioning records: which lines have been cut, which have been flushed, what they were flushed with, and who signed it off.
• Whether the systems are air gapped: not isolated on paper. Physically broken, open and proven.
• Where the low spots and dead legs are: product traps in the bottom of vessels, in sumps, under launders and in pipe runs that were never designed to drain. A flushed system with a trapped low spot is not a clean system.
• The hazardous material survey, and whether it covers plant as well as buildings: most surveys cover the buildings and stop at the process equipment. Gaskets, lagging, seals and linings are where the asbestos usually is.
• Residual chemical testing and the clearance standard: what has to be measured, to what level, and who signs the certificate that lets a crew put a shear through it.

If the answer to several of these is that nobody knows, that is a useful answer and it should be said in the tender documents rather than discovered on site. It tells every bidder to price an investigation phase, and it stops one of them pretending the problem is not there.

The site: access, services and who else is there

• Access for heavy plant: road condition, bridge and culvert limits, whether the last stretch is sealed. On remote sites this decides whether machines are floated in or hired locally, and the difference is substantial.
• Laydown and processing areas: where steel can be cut down, sorted and stockpiled. A site with nowhere to process is a site where everything gets handled twice.
• Live services through and around the area: power, water, compressed air, fire systems, and anything running to plant that is staying.
• Ground vibration limits: if there are centrifuges, cyclones, turbines or instrumentation still operating nearby, someone has set a limit. We need to know it before we choose a method, not after a complaint.
• Who else is working on site at the same time: interface management is a cost and a programme risk.
• Work hour restrictions, blackout periods and shutdown windows.

The commercial and regulatory frame

• Which isolations, permits and handovers the owner does before the contractor mobilises, and which are expected to be in the contractor's scope. This single line removes more argument than any other.
• Who owns the scrap, on what basis the credit is calculated, and who pays the freight: a recovery credit calculated at the mill gate and a credit calculated at the site gate are very different numbers, particularly a thousand kilometres from a scrap market.
• Tank and vessel cleaning: owner scope or contractor scope: say which. It is usually the least predictable cost on the job and the place a bidder is most likely to come unstuck.
• Waste classification and where it goes: the nearest licensed facility that will accept the material, and whether it will accept it at all.
• Licensing: what class of demolition licence the work requires in that state, and what the owner expects to see with the tender.
• Programme: target start, target finish, and whether those dates are driven by anything real.
• A submission date: surprisingly often missing.

What good looks like

The best enquiries we receive do three things. They state clearly what is in scope and what is not. They are honest about what is unknown. And they give every bidder the same pack at the same time.

That last one matters more than owners realise. If one contractor has had the scope for five days longer than the others, the prices are not comparable, and the owner has quietly narrowed their own field.

None of this is about making the tender process longer. A complete pack usually shortens it, because the questions that would otherwise come back one at a time over three weeks are answered up front.

Questions we get asked

We do not have all of this. Should we wait?

No. Send what you have and say plainly what is missing. A contractor who knows what they do not know can price an investigation phase properly. A contractor who is guessing cannot.

Can you help put the information pack together?

Yes. We do this as a separate piece of work, either as a scoping exercise or as part of a demolition methodology and consulting engagement. It is often the cheapest money an owner spends on the project.

How early is too early to talk to a demolition contractor?

There is no such thing as too early. Cost studies for closure provisioning are built the same way a tender is built, and doing one years ahead means the provision is defensible and the surprises are found while there is still time to plan for them.

Does this apply to a single circuit, or only a whole plant?

It applies to both. A single circuit inside a running plant is in some ways harder, because every isolation has to be proven against plant that is still operating next to it.

Where to next

If you are working through a plant or a mine site, start with mine demolition, decommissioning and closure, or talk to us about a cost study. If the plant is staying in production while one part comes out, live plant decommissioning is the page you want.