How to Quote and Run a Commercial Plastering Contract

What you will learn

• Commercial plastering is priced per square metre by specification category - skim, float and set, board and skim, and render are each priced and measured separately from drawings.
• A plasterer covers 20-40 square metres of skimming per day - use this to check whether the programme is achievable with your proposed gang size.
• Confirm whether the contract is supply-and-fix or labour-only before pricing - materials represent 15-25 percent of a supply-and-fix contract value.
• CIS registration is mandatory on commercial projects - without gross payment status, the main contractor will deduct 20 percent from your labour payments.
• Variation orders must be agreed in writing before carrying out additional work - verbal site instructions do not create a legal entitlement to payment.
• Submit payment applications on time with a measured breakdown - a late or undocumented application can delay payment by a full calendar month.

Commercial plastering contracts work very differently from domestic jobs. On a house, you agree a price with a homeowner, turn up, and invoice when the work is done. On a commercial project, you are working to an architect's specification, a main contractor's programme, and a sub-contract agreement that defines how, when, and how much you get paid. Getting the quote wrong by ten percent across 2,000 square metres is the difference between a profitable contract and one that loses you money. Getting the programme wrong means your crew stands on site for three weeks with nothing to plaster because first-fix trades are still running late.

This guide covers the full cycle - from reading tender documents and measuring up, through pricing, contracting, site coordination, and variation management, to submitting payment applications and closing the final account.

Key Takeaways

• Commercial plastering is priced per square metre by specification category - skim, float and set, board and skim, and render are each priced and measured separately from drawings.
• A plasterer covers 20-40 square metres of skimming per day - use this to check whether the programme is achievable with your proposed gang size.
• Confirm whether the contract is supply-and-fix or labour-only before pricing - materials represent 15-25 percent of a supply-and-fix contract value.
• CIS registration is mandatory on commercial projects - without gross payment status, the main contractor will deduct 20 percent from your labour payments.
• Variation orders must be agreed in writing before you carry out additional work - verbal site instructions do not create a legal entitlement to payment.
• Submit payment applications on time with a measured breakdown - a late or undocumented application can delay payment by a full calendar month.

Assessing the Scope and Measuring Up

The first task on any commercial tender is to get the drawings and specification in front of you before you estimate a single square metre. Commercial plastering specifications set out exactly what finish is required in each location - skim only over existing plaster, float and set on new blockwork, board and skim on metal-frame partitions, or external render on the facade. Each category carries a different m² rate and a different production rate for your gang, so mixing them up in your take-off will wreck your margin.

Measure every area from the architectural drawings and cross-check against the specification. Wall areas are measured net - door and window openings are deducted, but their reveals are added back in. High ceilings matter: a 4.5m ceiling height versus a standard 2.4m ceiling changes both the scaffold requirements and how much your crew can produce in a day. Make a note of any areas that need access equipment and price it into your overhead allowance.

Check the specification for the preparatory work included in your scope. On some commercial contracts, the main contractor provides a drylining package and hands you plasterboard-lined walls ready to skim. On others, your scope starts at bare blockwork and you are responsible for bonding coat, browning, and finish. That distinction roughly doubles your cost per square metre, so confirm it in writing before you price.

Pay attention to the bead schedule. Angle beads to external corners, stop beads at junctions with different finishes, and movement beads across expansion joints are often listed separately. Some main contractors price beads as a provisional sum; others expect you to include them. If the specification is silent, ask for clarification - do not assume they are included.

Pricing the Quote

Commercial plastering is almost always priced per square metre rather than on a day rate. Day-rate contracts shift the risk to the main contractor; m² contracts mean you carry the production risk but benefit fully from your crew's efficiency. For commercial sub-contracting work, m² pricing is the industry standard.

In Q3 2026, realistic UK commercial rates for supply-and-fix plastering are: skim coat over sound plasterboard at £15-25 per m², float and set (two-coat work on blockwork) at £22-35 per m², and board and skim at £25-40 per m². These ranges widen between London - where plasterer day rates run £250-450 - and regional markets, where rates of £150-250 per day are more typical. External sand-and-cement render runs £40-70 per m², while silicone or through-coloured monocouche systems reach £55-95 per m² before scaffolding.

Your check figure is output per operative per day. A plasterer skimming pre-boarded walls covers 20-40 square metres per day depending on the complexity of the areas and the number of reveals and cuts. Float and set on blockwork takes longer - an operative might cover 15-25 square metres per day on a straightforward elevation. Work backwards from the programme duration to confirm your gang size will deliver the measured areas within the allotted programme period.

On commercial projects, confirm whether the contract is supply-and-fix or labour-only. Labour-only contracts are common where the main contractor bulk-purchases British Gypsum or Knauf materials direct. In this model you provide the operatives, tools, and any small consumables; the main contractor supplies plaster, board, beads, and fixings to the working area. This changes your quote significantly, because materials represent 15-25 percent of a supply-and-fix contract value.

Include allowances in your overhead for CIS deductions (if you do not hold gross payment status), public liability and employers' liability insurance, parking and travel, and any site-specific requirements such as CSCS cards, PPE, inductions, and tool registration. Main contractors on larger commercial projects often impose attendance requirements - for example, a specified weekly gang size, a site manager point of contact, or a requirement to attend progress meetings. Price these into your overhead rather than assuming they are costless.

The Sub-Contract Agreement and CIS

Before mobilising to site, you need a signed sub-contract agreement. Most main contractors use a bespoke form based loosely on JCT DOM/2 terms, a JCT Minor Works sub-contract, or a simple letter of intent with schedule of rates attached. Whichever form is used, the following points must be confirmed in writing before you start.

Programme dates: the earliest date your gang can mobilise, the expected start date for plastering on each section or floor, the required completion date, and any sectional completion obligations (for example, if certain areas need to be finished ahead of the rest for the fit-out trade to follow). Agreeing a programme in writing protects you if the main contractor hands over late - you can document the delay and claim for standing time or loss of productivity.

Payment terms: under the Housing Grants, Construction and Regeneration Act 1996, commercial construction contracts must include an adequate mechanism for determining what payments are due and when. The standard approach is monthly payment applications with a 30-day payment period. The main contractor has five days from your application to issue a payment notice; if they intend to pay less than you applied for, they must issue a pay less notice at least five days before the payment due date. If they issue neither, you are entitled to the full applied amount. Know these dates - they are your legal protection.

Retention: commercial contracts typically hold back 5 percent of each certified payment as retention. Half of the retention is released at practical completion; the remaining 2.5 percent is held until the end of the defects liability period, commonly six or twelve months after practical completion. Be aware that the Commercial Payments Bill, currently progressing through Parliament (at second reading in the House of Lords in June 2026), proposes to ban retention clauses in construction contracts outright - but this is not yet law, so standard retention provisions will apply to contracts signed now.

CIS registration: if you operate as a limited company or sole trader sub-contractor, the main contractor is legally required to verify your CIS status with HMRC and deduct 20 percent from your labour payments (30 percent if you are unregistered). Gross payment status - where no deduction is made - requires a separate HMRC application and minimum turnover thresholds. Confirm your CIS status before the first payment application to avoid a deduction you were not expecting.

Managing the Programme and Sequencing with Other Trades

Plastering is a mid-programme trade on any commercial fit-out. You follow the drylining, first-fix plumbing, electrical, and mechanical trades. You precede the second-fix electrical, decorating, floor finishes, and ceiling tile installation. Getting squeezed from both directions is the most common cause of quality problems and programme overruns.

At the start of the contract, agree in writing the specific conditions that must be met before your gang mobilises to any section. The standard requirements are: plasterboard fixed and taped by the dryliner (if boards are being supplied by another trade), first-fix pipes and conduits chased and capped, and the building weathertight and dry. If you start plastering in a section that is still taking water through the roof or has open penetrations, the plaster will fail and you will be expected to redo it at your own cost.

Plan your drying time into the programme. Fresh plaster typically takes three to seven days to dry sufficiently before painting can begin, and longer in unheated buildings or humid conditions in winter. If the decorator is scheduled to follow two days after your planned completion, there is a programme conflict that needs resolving before you start - not after you finish.

Keep a daily site diary recording gang size, areas worked, and any delays caused by other trades or the main contractor. On a contract with a tight programme, being able to demonstrate that your gang was on site and ready but could not proceed because an area had not been handed over is the foundation of a valid extension of time claim.

Managing Variations on Site

On commercial projects, the specification will change. Architects issue revised drawings, clients ask for an upgraded finish in reception areas, and areas that were specified as skim-only turn out to need float and set because the original blockwork was not built to tolerance. Every one of these changes is a variation and every one of them needs to be captured, valued, and agreed before the work is carried out.

The golden rule on commercial projects: do not carry out additional work on a verbal instruction alone. A site manager telling you verbally to add two rooms to your scope is not an instruction that creates a legal right to payment. What you need is a written site instruction, an architect's instruction, or a variation order signed by the main contractor. If a verbal instruction is given and the work is genuinely urgent, follow up the same day with a written record - an email stating the date, what was instructed, who instructed it, and the fact that you are carrying it out under protest pending a written instruction.

Maintain a variation log throughout the contract. Record every instruction with the date received, the source, the area or description, your measured quantity, your unit rate, and the agreed or claimed value. Include the status of each variation: submitted for agreement, agreed, disputed, or included in a pending payment application. A complete variation log makes the final account straightforward; an incomplete log makes it a dispute.

Day-work rates apply to small additional works that are too irregular to measure by area - for example, patching around new service penetrations or making good around newly installed door frames. Agree day-work rates in the sub-contract at the outset. Keep day-work sheets for any labour and materials used on day-work items and get them signed by the main contractor's site manager on the day, not at the end of the project.

Payment Applications and Final Account

On a commercial contract, you do not submit an invoice and wait to see what happens. You submit a payment application at the agreed assessment date each month, setting out the total value of work completed to date, less any deductions for retention, less any previous certified payments. The difference is the sum you are applying to be paid.

Structure your application clearly. Break it down by section or floor to match the programme structure. Include measured areas for each specification category - this makes it verifiable by the main contractor's quantity surveyor and reduces the risk of a pay less notice cutting your application on the grounds of insufficient detail. Attach your variation log as a schedule to the application, identifying which variations are included in the claimed sum and which remain unagreed.

At the end of the contract, submit a final account setting out the total measured value of the works, all agreed variations, any claims for extension of time costs, and any outstanding retention. The final account should be submitted promptly after practical completion of your scope - not left open for months. The sooner it is agreed, the sooner the retention schedule starts running and the sooner you get paid the balance.

Closing the Contract

Your obligations do not end when you walk off site. The defects liability period keeps you on call to return and make good any items that fail within the agreed period - typically six to twelve months. Keep a record of all snagging items raised at practical completion and the dates on which they were rectified. When the defects liability period expires, write formally to the main contractor requesting release of the final retention and confirming all outstanding defects have been made good.

On larger commercial projects, the gap between completing the work and receiving the final retention payment can run to twelve months or more. Factor the expected retention balance into your cash flow forecast from the start - tracking it consistently means it does not come as a surprise when funds are tight six months in. Zigaflow's quote and job management tools can handle m² take-off schedules, variation logs, and payment application tracking in a single place rather than spread across spreadsheets and email threads.

Sources

• Plastering Cost UK 2026 | £15-90/m² Skim, Re-Plaster, Plasterboard & RenderBestBuilders · accessed 2026-07-21
• Plastering Costs UK 2026 (Per Room, Per m² and Day Rates)Kent Plasterers · accessed 2026-07-21
• The Commercial Payments Bill: Key changes for UK ConstructionBeale & Co · accessed 2026-07-21

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