How to scope and tender a water ingress repair

Why three quotes for the same leak never agree

A committee obtains three quotes and finds they range from $2,400 to $9,800 for what looks like the same wall. The instinctive reading is that somebody is gouging. The actual reading is almost always that the three contractors have quoted three different jobs, because nobody told them what the job was.

The first problem is the unit. This trade prices in at least four incompatible ways and no two quotes will pick the same one unless you make them. One contractor quotes a lump sum for "crack injection to the car park western wall". The second quotes a rate per linear metre with the quantity to be measured on site. The third quotes per crack, at a rate per crack, with a crack count from a walk-through. Those three numbers cannot be reconciled after the fact, and per-crack pricing in particular rewards a contractor for identifying fewer, longer cracks.

For orientation, these are the indicative market bands in south east Queensland. Polyurethane crack injection through accessible, straightforward walls runs roughly $150 to $450 per linear metre. Long, repetitive runs on a single site drop toward $80 to $200 per linear metre because the set-up cost amortises. Difficult access, work at height, confined space or occupied premises pushes it to $450 to $900 per linear metre. Construction and cold joints are dearer than cracks at $200 to $500 per linear metre, because joints are wide, connected, take more resin and need closer packers. Tie-bolt and form-tie holes price individually at $45 to $120 each with a minimum job of $600 to $1,200. Underneath all of it sits a site attendance minimum of roughly $450 to $900 plus GST, because somebody has to travel, set up a pump, work, and come back to make good.

The second problem is scope depth. Two contractors can both quote per linear metre and still be quoting different work, because one has priced mechanical packers and a return visit for make good, and the other has priced surface ports, one attendance and no reinstatement. The rate looks comparable. The job is not.

The fix for both problems is the same and it is entirely within the committee's control. Write the scope yourself, issue it to every tenderer, and require them to price against it.

Before you tender anything: establish the defect

The most expensive mistake a committee makes is not choosing the wrong contractor. It is tendering a repair before anyone has established where the water gets in.

This trade's own first rule is that the crack you can see is very often not where the water enters. Water tracks laterally between a membrane and the concrete, and between a structural slab and its topping, then exits at whatever is now the weakest point, frequently metres from where it entered. In a basement, the joint where the wall meets the floor slab — the kicker joint — is usually the real path even when a crack higher up the wall is what everyone is looking at. Tender the visible symptom and you buy a repair for the wrong element.

The things that must be ruled out before a repair scope is written are drainage, a leaking service, condensation and membrane failure. Blocked or absent subsoil drains, blocked weep holes, missing falls, downpipes discharging at the footing and blocked planter box outlets are the actual cause behind a very large share of enquiries that arrive asking for injection. A leaking main or a corroded sewer is quick to exclude with a pressure test and expensive to miss. Damp on cold surfaces in a still, humid, poorly ventilated plant room with no correlation to rain is very often condensation, and injection achieves nothing there except the cost of it.

The investigation costs are modest against the repair. A quote-only site visit is commonly free. A diagnostic investigation with moisture readings, crack monitors installed, water testing, ground-penetrating radar scanning and a written report sits at roughly $450 to $1,500. A structural engineer's assessment is separate again, typically $1,200 to $3,500 or more. Where movement is in question, tell-tales fitted across the cracks and read over 4 to 12 weeks so the readings span a temperature and moisture cycle is cheap insurance and cheaper than a rigid repair in a moving crack.

A committee that spends $1,200 establishing the cause and then $18,000 on the correct repair is materially ahead of one that spends $12,000 twice on the wrong one, and it also has a defensible record if the matter turns into a defect claim or an insurance argument later.

The scope of works template, clause by clause

Copy this structure into a document, fill the blanks, and issue the same document to every tenderer. Each clause below gives the heading and what to write underneath it. Clauses you genuinely do not need can be deleted, but delete them consciously rather than by omission, because every clause you leave out becomes a variation later.

1. 1. Project and property identificationScheme name, community titles scheme number, street address, the committee's contact and the strata manager's contact, and a single nominated point of contact for site queries. Name the person a tenderer rings when they find something unexpected, because the alternative is that they price a contingency instead.
2. 2. The element and its accessDescribe the element precisely enough that a stranger could find it: the northern basement car park wall between column lines 4 and 9, level B1. Attach a marked-up plan. State access hours, height clearance for plant, loading dock arrangements, induction requirements and whether the area can be closed at all.
3. 3. The defect as observedWhat has been seen, by whom, since when. Attach dated photographs, the incident log, resident reports and any body corporate maintenance records. State whether it is constant, only during and after rain, or seasonal. Give the number of separate locations if known.
4. 4. Investigation already carried out and what it foundAttach the diagnostic report, moisture readings and their marked locations, tell-tale readings and their dates, water test results and any radar scan output. State explicitly what has been ruled out and by whom: drainage inspected, services pressure-tested, condensation considered, membrane assessed. This is the clause that lets a competent tenderer price confidently instead of defensively.
5. 5. Scope boundary: included and expressly excludedList what is in and, more importantly, what is out. Common exclusions worth naming so they are not assumed either way: render and paint reinstatement, floor covering replacement, tenant contents, drainage rectification, engineering fees, and any concrete repair arising if corrosion is found.
6. 6. Basis of measurementNominate the unit and require all tenderers to use it. For cracks and joints, a rate per linear metre with cracks itemised in a schedule and quantities measured on completion. For discrete defects such as tie-bolt holes, a rate per hole with a stated count. Do not accept per-crack pricing and do not accept an unquantified lump sum. State whether rates are ex-GST.
7. 7. Method requirementsSpecify: 13 mm mechanical packers with non-return valves, drilled at 45 degrees, offset from the crack line by approximately half the element thickness so the hole intersects the crack at mid-depth, drilled to between two-thirds and three-quarters of the element thickness and never through the far face. Packer spacing stated as a band, typically 150 to 400 mm centres, tighter for hairline cracks and closer again on joints. Water flush through each packer to prove hydraulic connection before injecting. Injection sequenced bottom to top on vertical cracks and consistently end to end on joints. Packers left in a minimum of 24 hours before cut-back.
8. 8. MaterialsRequire the tenderer to nominate the resin family and justify it in one sentence against the moisture regime: hydrophobic polyurethane for active flow that dries out seasonally, hydrophilic polyurethane or acrylate gel where the element stays permanently wet, epoxy only for dry dormant structural cracks. Require current safety data sheets and any conformity claims such as EN 1504-5 classification, stated as product conformity rather than code compliance. Where potable water is involved, require the current AS/NZS 4020 certificate for the specific product.
9. 9. Structural scanning and approvalsRequire ground-penetrating radar scanning before drilling any structural element and written engineer approval before drilling any post-tensioned slab. Require the tenderer to state the maximum injection pressure it will apply and to obtain an engineer's nominated maximum in writing for thin panels, blockwork and prestressed or post-tensioned elements.
10. 10. Safety and compliance items to be priced separatelyRequire confined space compliance under AS 2865 to be itemised as its own line where lift pits, tanks, sumps or enclosed plant spaces are involved: entry permit, atmospheric testing, standby person, communications and rescue provision. Require on-tool dust extraction or wet drilling for respirable crystalline silica, particularly in enclosed basements. Require the safety method statement and the certificates of currency for public liability and workers compensation to be supplied with the tender.
11. 11. Access equipment, traffic management and hoursState whether the works can proceed in business hours or whether after-hours or weekend work is required, and require any penalty loading to be shown as its own line rather than absorbed into the rate. Require traffic management on any operating car park to be itemised separately, with the number of controllers and days shown. Require access plant — scissor lift, knuckle boom, scaffold — to be itemised with the type and the number of days.
12. 12. Vehicle and property protectionOn a car park deck, require the protection method for parked vehicles to be described. One resin drip on a bonnet costs more than a small job, and it is worth knowing whose insurance the committee is relying on before it happens rather than after.
13. 13. Making good and reinstatementRequire packers cut or snapped 10 to 20 mm below the finished surface a minimum of 24 hours after injection, the recess filled with a non-shrink hydraulic plug or polymer-modified repair mortar, and ground or trowelled flush. State the required final finish: bare concrete left as-is, or render and paint reinstated. If reinstatement is required, say so here, because it is frequently a larger line than the injection itself.
14. 14. Resident notification and disruption planRequire a written notification the body corporate can distribute, a staging plan showing which bays or areas are closed on which days, expected noise and odour periods, and the arrangement for residents who cannot access their bay. Require a named site supervisor and a contact number for the duration.
15. 15. Verification and handover documentationRequire observation of the treated area for a minimum of 24 to 48 hours and, where practical, across a rain event. Require moisture meter readings at marked points before and after. Require comparable photographs taken before and after from the same positions, together with a written description of what was found and what was done. Require flood or hydrostatic testing where the geometry allows, such as a lift pit dewatered and observed or a tank tested to the AS 3735 leakage criteria.
16. 16. Provisional sums and the variation mechanismNominate provisional sums for the things nobody can know until the surface is opened: additional cracks revealed on exposure, void filling behind the element, and concrete repair if corrosion is found. Set a written approval threshold above which no variation proceeds, and require variations to be priced against the tendered rates rather than negotiated fresh.
17. 17. WarrantyRequire the warranty term, its scope, its exclusions and its claim process to be supplied as a document with the tender, not described in a sentence. Expect and accept that the warranty covers the specific cracks and joints sealed rather than the building as a whole, and require the schedule of sealed locations to be supplied with the warranty so a later claim can be resolved from the record.
18. 18. Programme, milestones, payment and tender return formatState the required start window, the maximum duration, and the milestones — including the return visit for cut-back and make good, which is a separate attendance and must appear in the programme. State the payment terms and any retention. Specify the tender return format: a priced schedule matching your clause numbering, a lump sum summary, a list of exclusions, and the certificates. Set a closing date and state that non-conforming tenders will be returned for re-pricing.

Reading the quotes that come back

Once the tenders arrive, the differences that matter are rarely in the headline number. They are in ten specific places, and each one has a plain-English test.

A worked reconciliation of three quotes

This is an illustrative example built from the market bands above, not a real tender and not a real building. Its purpose is to show a committee how to take three incompatible numbers apart.

The scope: 22 linear metres of cracking across a basement car park wall, ground level, accessible from a scissor lift standing on flat slab, business hours available, bare concrete finish, no confined space, no post-tensioned element involved.

Quote A comes in at $6,200. That is about $282 per linear metre, which sits comfortably inside the $150 to $450 accessible band. The scope names mechanical packers, two attendances, packer cut-back and hole filling, and a handover pack including before and after photographs taken from the same positions.

Quote B comes in at $2,400. That is about $109 per linear metre. It sits below the accessible band and close to the $80 to $200 rate that applies to long repetitive runs on a single site — except this is 22 metres of discrete cracking, which is not a long repetitive run. Read the scope and the reason appears: surface ports, one attendance, make good not mentioned. It is not a cheaper version of quote A. It is a different job.

Quote C comes in at $9,800. Strip it out and the injection line is about $445 per linear metre, at the top of the accessible band. But the quote also carries a $1,600 line for removing and reinstating render across the affected area, and a $900 provisional sum for additional cracks revealed once the render comes off. Neither of the other two priced either of those things.

The reconciliation is where the committee's real decision sits. A and C are quoting the same repair; C has included exposure and reinstatement, and A has not, which means A's number will grow by roughly C's render line if the wall turns out to be rendered. B is quoting a materially different method with a materially shorter life. So the question to put to the committee is not which quote is cheapest. It is: does our scope require the render removed and reinstated, and if it does, why did A not price it — because either A did not read the scope, or A intends to raise it as a variation.

This is precisely why clause 5 and clause 13 of the template exist. Written properly, all three tenderers price the render, and the three numbers converge to within a normal commercial spread.

Twelve questions to ask every tenderer, including us

Ask all of them, of everyone, and write the answers down beside each quote. Contractors who do good work enjoy these questions. The reaction to being asked tells you almost as much as the answers do.

• Are you drilling and installing mechanical packers, or gluing ports to the face? At what spacing and at what angle?
• Will you come back and check the repair after the next real rain event, and how long after completion?
• How many attendances are in your programme, and when do the packers come out?
• Is making good included, and does that include render and paint reinstatement or only filling the packer holes?
• Is your price per linear metre, per crack, per hole or lump sum, and how will the final quantity be measured?
• Will you water-flush the packers before injecting to prove the crack connects, and what do you do if resin does not appear at the next packer?
• Which resin family are you proposing and why, given whether this element stays wet all year or dries out?
• What maximum injection pressure will you apply, and who nominated it?
• Will you scan before drilling, and what is your process if any part of this element turns out to be post-tensioned?
• What documentation do we receive at handover — before and after photographs from the same positions, a written description of what you found and what you did, and before and after moisture readings?
• What exactly does your warranty cover, what does it exclude, and can we see the document before we award?
• What have you excluded from this price that we should expect to see as a variation?

Common property, lots, and who pays

Before the committee spends anything, settle whose problem it is, because it determines which fund pays and whether an owner has a separate claim.

As a general pattern, the elements this trade works on are almost always common property even when the water appears inside a lot: basement and below-ground walls, structural slabs, the slab-to-wall joints, lift pits, car park decks and soffits, podium planter boxes and the building envelope. What sits inside the lot — internal linings, floor coverings, contents, and often the finishes damaged by the water — is usually the owner's.

The precise dividing line, and the body corporate's maintenance obligation, are governed by Queensland body corporate legislation and by the regulation module the scheme is registered under. Confirm the position with your strata manager in writing before the committee commits, rather than assuming it. Committees get this wrong in both directions, and both are expensive: paying for something that was a lot owner's, or refusing something that was common property and inheriting a dispute.

Insurance is a separate question and usually a disappointing one. As a general pattern, gradual water ingress and defective waterproofing are commonly excluded from strata policies, while sudden accidental damage may be covered. Where the building is newer, the defect may instead be a builder's defect matter with time limits that make delay costly. In Queensland, residential work over $3,300 performed by a licensed contractor also carries home warranty insurance obligations. We cannot advise on any particular policy, but the practical point is the same in every case: get the diagnosis documented before the repair, not after. Once the crack is filled, the evidence is inside the wall.

One more thing worth deciding early: who pays for the investigation. Our view is that the body corporate should fund it where the element under investigation is common property, even if the water is appearing in one lot, because the investigation is establishing the condition of the body corporate's own asset and the report belongs to the body corporate afterwards.

The AGM cost paper, section by section

A committee can have the right scope, the right quotes and the right recommendation and still lose the vote, because the paper was written for engineers rather than for owners. The structure below is written to be read once, by somebody who is not technical, in a room where several people would prefer to defer the decision.

1. 1. The problem in one sentencePlain English, no jargon, no acronyms. "Water is entering the basement car park through the western wall and has been since March, and the repair we recommend costs $X." Everything else in the paper supports that sentence.
2. 2. What has been observed and since whenDates, photographs, the incident log, the number of affected bays or lots. Facts with dates against them, because the first question from the floor is always how long this has been going on.
3. 3. What was investigated and what it foundName the investigation, its cost — which has already been spent — and its conclusion in two sentences. Attach the report rather than summarising it at length. If drainage, a leaking service or condensation was ruled out, say so explicitly, because somebody in the room will suggest each of them.
4. 4. The cost of doing nothingQuantify it where it can be quantified: continuing damage to finishes, corrosion of reinforcement over time, the risk to the building's insurance position, disruption to owners, and the likelihood that the repair cost rises rather than falls. Where it cannot be quantified honestly, say that rather than inventing a figure.
5. 5. The options considered, all of themIncluding do-nothing and including the full positive-side repair the committee cannot afford. Cost band and duration against each. Owners vote more readily for a recommendation when they can see what was rejected and why, and this section is also the committee's record of a properly considered decision.
6. 6. The recommendation and the reason, in two sentences an owner can repeatIf an owner cannot explain the recommendation to their neighbour in the car park afterwards, the paper has not done its job.
7. 7. The quotes, normalisedPresent all quotes converted to the same unit, with a short note naming each scope difference: "Quote B is $2,400 lower because it does not include render reinstatement or making good." This is the single most persuasive part of the paper and the reason the scope was written first.
8. 8. The funding sourceAdministrative fund, capital works fund, special levy, insurance claim, or a combination. Show the current balance of the fund you are proposing to draw on and what remains afterwards, because the objection from the floor will be about what else the money was for.
9. 9. The motion as it will be putThe exact wording, the resolution type, and confirmation from the strata manager that the resolution type and the committee's spending authority are correct for this scheme's regulation module. Getting this wrong invalidates a decision the committee has spent months reaching.
10. 10. The disruption planWhich areas close, on which days, for how long, what the noise and odour will be like and when, and how affected owners will be notified. Attach the contractor's staging plan. Disruption is what owners actually vote on emotionally, and answering it in the paper removes it from the debate.

When a special levy is actually needed

Committees reach for a special levy earlier than they need to, and then raise it against a number that turns out to be wrong. Both are avoidable.

Start with the authority question, and get it answered by your strata manager rather than assumed. The committee's own spending limit, and the type of resolution required to approve works of a given value, depend on the regulation module the scheme is registered under and on the body corporate's own past resolutions. There is no single dollar figure that applies to every Queensland scheme, and we are not going to publish one, because a committee acting on a number that does not apply to its module has a defective decision on its hands.

With that settled, the practical triggers for a special levy are these. The repair cost exceeds the balance available in the fund the works properly belong to. The sinking fund forecast never contemplated this defect, which is very common with water ingress because forecasts are built around planned renewal rather than unplanned failure. The works are urgent and fall outside the budget cycle. Or the scope goes beyond maintenance into improvement or betterment, which may change both the fund and the resolution type required.

Then the sizing, which is where committees most often go wrong. Size the levy on the tendered price plus the provisional sums plus a contingency, not on the headline number. A scope written properly will carry provisional sums for cracks revealed on exposure, for void filling and for concrete repair if corrosion is found, and those sums exist precisely because they are likely to be drawn on. A levy raised against the base quote alone is a levy you will be raising a second time, at a second meeting, having lost credibility with owners in between.

And the sequencing. Do not raise a levy before the scope is settled and the quotes are normalised. A levy raised against a lump sum nobody can compare is a levy raised against a number that will move. Settle the scope, tender it, normalise the quotes, then size the levy.

Holding any contractor to it, including us

The last section is the one that makes this page worth publishing. Here is how a committee holds the winning contractor to the scope after the vote is over and the attention has moved on.

Require the handover pack before the final payment, not after it. It should contain the before and after photographs taken from the same positions, a written description of what was found and what was done, the before and after moisture readings at marked points, the safety data sheets, current certificates of currency for public liability and workers compensation, the contractor's licence details, and the warranty document with its exclusions. None of that is exotic; a contractor doing the work properly is generating all of it anyway.

Re-inspect at 6 and 12 months, and specifically after the first sustained wet period. In south east Queensland the wet season runs roughly November to March, and a repair that has not seen a proper rain event has not really been tested.

Then accept one exclusion, because it is honest and any contractor who does not state it is either not thinking or not telling you. A warranty on injection covers the cracks and joints that were sealed. It cannot cover a new leak at a different location, because sealing from the dry side redirects water rather than removing it, and it cannot cover water finding a way in because a drain blocked or a membrane failed elsewhere. That is physics, not weaselling. The schedule of sealed locations and the before and after photographs are what make the distinction resolvable in minutes rather than months, which is exactly why clause 15 requires them.

Be suspicious of the opposite promise. If a contractor offers to guarantee that no further water will enter your car park anywhere, from a repair carried out entirely from the inside, they have promised something the method cannot deliver. Ask them to put the scope of that guarantee in writing, listed location by location, and watch what happens to it.

Questions we actually get asked

How many quotes does a body corporate need before it can award the works?

The number and the resolution type depend on the regulation module your scheme is registered under and on the value of the works, so confirm it with your strata manager rather than working from what another building did. Practically, three comparable quotes is the working standard, and the operative word is comparable. Three quotes against three different scopes is worse than two quotes against one properly written scope, because it gives the committee the appearance of diligence without the substance of it.

One quote is priced per crack and another per linear metre. How do we compare them?

You cannot compare them reliably after the fact, and this is the reason the scope should nominate the unit before tendering. If you are already holding both, go back to each tenderer with your own crack schedule — location, length in metres, approximate width — and ask both to re-price against it per linear metre. Per-crack pricing is the one to be most careful with, because it rewards a contractor for identifying fewer, longer cracks, and the crack count is set by the person quoting.

The cheapest quote is about a third of the others. What is it leaving out?

In our experience it is usually three things in combination. Surface ports glued to the face instead of drilled mechanical packers, which is faster and cheaper and will not hold on an actively leaking wall. One attendance instead of two, which means either the packers come out before 24 hours or there is no making good. And no verification documentation. Ask the cheapest tenderer those three questions directly. If the answers confirm it, the quote is not cheap, it is for a different job.

Do we need an engineer involved before we go to tender?

For most leak sealing in a basement wall, a lift pit or a planter box, no. You do need one where the cracking might be structural — diagonal cracks, cracks that widen toward the top, any lean, bulge or floor level change, or cracking in beams, columns or other primary members. You also need one to approve any drilling into a post-tensioned slab and to nominate a maximum safe injection pressure for thin panels or blockwork. If a contractor thinks you need an engineer, they should say so before quoting rather than after, and if none of your tenderers raises it on a structure where it applies, that itself is information.

Can we require the contractor to guarantee there will be no further leaks anywhere in the car park?

You can require it, but nobody honest will give it, and a contractor who does has told you something about their contract rather than their competence. Sealing from the dry side redirects water rather than removing it, so a new path can open at a different location. What you should require instead is a warranty that lists the specific cracks and joints sealed, with the term, the exclusions and the claim process stated in a document you can read before award. That is enforceable. A blanket promise is not.

Should the body corporate or the affected lot owner pay for the investigation?

Our view is the body corporate, where the element being investigated is common property — which for basement walls, slabs, lift pits, car park decks and planter boxes it almost always is, even when the water is showing up inside one lot. The investigation establishes the condition of the body corporate's own asset and the resulting report belongs to the body corporate afterwards, including for any builder's defect or insurance argument. The dividing line between common property and lot in your specific scheme should be confirmed with your strata manager in writing before the committee commits.

What should we insist on receiving at handover?

Before and after photographs taken from the same positions, a written description of what was found and what was done, before and after moisture readings at marked points, safety data sheets, current certificates of currency for public liability and workers compensation, licence details, and the warranty document with its exclusions. Make it a condition of the final payment rather than a request afterwards. Without comparable before and after photographs in particular, a leak in 18 months becomes an argument instead of a five-minute check.

How long should we allow between issuing the scope and awarding?

Allow enough time for tenderers to attend site, because anyone quoting a water ingress repair from photographs alone is guessing. In practice that means two to three weeks from issue to close for a straightforward wall, longer where exposure of a rendered or lined surface is required before anyone can see the actual defect. Build the site attendance into the timetable explicitly, and if a tenderer returns a price without having visited, treat the number as indicative rather than firm.

Where to next

• request a scope of works
• car park slab and soffit leak sealing
• lift pit leak sealing and confined space costs
• what crack injection actually costs in Australia
• where negative side sits under the standards
• our warranty in full, including the exclusions
• fifteen times we'll tell you not to inject