Dayworks: the last resort, used first

Dayworks value work by the resources consumed: labour hours, plant time and materials, with percentage additions for overheads and profit. They are the fallback in the valuation hierarchy, applying where work cannot properly be valued by measurement.

That last clause is the whole subject. Dayworks are for work that cannot be measured, not for work that would be inconvenient to measure.

Where they sit in the hierarchy

Under JCT the valuation rules run roughly in this order:

1. Contract rates, where the work is of similar character and executed under similar conditions
2. Pro-rata rates, where the character is similar but the conditions differ
3. Fair rates and prices, where neither applies
4. Dayworks, where the work cannot properly be valued by measurement

The order is not a menu. A surveyor who reaches for dayworks without first considering whether a contract rate or a fair rate applies has skipped three steps, and at the final account that is exactly how it will be characterised.

When they are genuinely right

• Opening up and investigation where the extent cannot be known in advance
• Small isolated works interrupting other trades, where the disruption dominates the cost
• Emergency or out of sequence work carried out under instruction
• Alterations to existing fabric where the condition is unknown until exposed

The common thread is genuine uncertainty at the time of instruction. Once the work is done and its extent is known, that uncertainty has gone, and the argument for dayworks weakens.

What a daywork sheet must show

Contracts and the recognised definitions of prime cost require substantiation. A sheet that says "labour, 3 men, 1 day" is not substantiation. What is needed:

• The instruction the work was carried out under, identified by reference
• Date and location of the work
• Each operative named, with trade and hours, split between normal and overtime
• Plant by item and hours, distinguishing hire from owned
• Materials by quantity with supporting invoices
• Signature of the person verifying it, and the date of signature

What signing actually means

This causes more trouble than any other aspect. On most contracts, signing a daywork sheet is verification that the resources were on site as recorded. It is not agreement that dayworks are the correct valuation rule, nor that the work was a variation at all.

Say so on the sheet. A short endorsement, applied consistently, along the lines of "Signed as a record of resources only. Entitlement and basis of valuation reserved." That sentence has resolved a great many arguments before they started.

The five minute check

Before a daywork claim goes into a valuation:

1. Is there an instruction? No instruction, no variation, no dayworks.
2. Could this have been measured? Now that it is complete, could you measure it and apply a contract rate? If yes, ask why dayworks are being used.
3. Do the hours reconcile with site records? Compare against the allocation sheets or site diary. Six operatives on the sheet and four on site is a common and easily found discrepancy.
4. Are the percentage additions the contract ones? Overheads and profit percentages come from the contract or the tender, not from the definition's defaults.
5. Is any of this already in the measured work? The same labour appearing in a bill line and a daywork sheet is the single most common double count.

The record that matters at the final account

Two years later, a dayworks variation is defensible if you can show the instruction, the sheets, the verification and the reason dayworks were the right rule. Missing the last of those is what turns a defensible sum into a negotiated one.

So record the rule alongside the value at the time it is decided. It takes a few seconds while the reasoning is fresh, and it is the piece nobody can reconstruct afterwards.