What an M&E subcontractor site diary needs to survive adjudication

Adjudication turns on evidence. Not on who shouts loudest. Not on who has the better barrister. When an adjudicator sits down with a payment dispute between an M&E sub and a main contractor, they want contemporaneous records. Records that prove what happened, when, and who was responsible.

Most M&E subs don't have these records. They have fragments: a few photos on someone's phone, some WhatsApp messages, weekly reports that say "work ongoing on level 4." When the dispute lands and lawyers start asking for evidence, there's a frantic scramble to rebuild a timeline from memory and emails. By then it's too late. Records created after the fact carry almost no weight. The adjudicator knows the difference.

If your site diary wouldn't survive scrutiny in adjudication, you're gambling. Every project is one payment dispute away from your records deciding whether you get paid.

What adjudicators actually look for

I've been through enough adjudications to know what matters. Adjudicators look for three qualities in your records:

Contemporaneous. The record was made at or near the time the event happened. A diary entry written on Monday about Monday carries far more weight than an email written 3 months later. The closer the record is to the event, the more credible it is.

Specific. The record has enough detail to be useful. "Worked on level 3" tells the adjudicator nothing. "Installed 45m of 100mm LTHW pipework on level 3, east wing riser to FCUs serving rooms 3.14 to 3.22" tells them exactly what was done and where.

Consistent. The records form a coherent picture over time. If your diary says 12 operatives every day for 3 weeks, but your labour records show 8, you have a credibility problem. The adjudicator will assume the lower number. Or worse, they'll doubt all your records.

The 5 records that win disputes

You don't need paperwork for the sake of it. But you do need these 5 records, maintained consistently throughout the project:

1. Daily site diary. This is the backbone. Every day your team is on site, someone records: date, weather, number and trades of operatives, work carried out and where, instructions received (verbal or written), delays or disruptions, and H&S issues. It takes 10 minutes at end of day. No excuse for not doing it.

2. Labour allocation records. A daily log of who was on site, their trade, and what area they worked on. This is separate from payroll. It's a site-level record of where your people actually were. When you need to prove the labour impact of a delay, this is the record that does it. Without it, you're estimating. Estimates are easy to challenge.

3. Photographic records with metadata. Photos of work in progress, taken daily, with date, time, and location identifiable. Modern phones embed GPS coordinates and timestamps in the EXIF data automatically. This is powerful evidence because it's very hard to fabricate. Photograph progress at the same locations regularly to build a visual timeline. Photograph any obstructions or incomplete preceding work.

4. Delay and disruption log. Every time your team can't work in an area because of the main contractor or another trade, record it that day. State: date, area affected, what the obstruction is, which operatives were affected, what they did instead (stood down, redeployed, sent home). This supports your extension of time and loss-and-expense claims.

5. Correspondence log. Every instruction, notification, RFI, and drawing issue, logged with date sent or received, who from, who to, and what it related to. In adjudication, chronology is critical. If you can show you notified a problem on a specific date and the PM didn't respond for 3 weeks, that tells a story. But only if you can prove the dates.

Why WhatsApp records fail

I need to address this because it comes up constantly. M&E site teams live on WhatsApp. Instructions get given in group chats. Progress photos get shared in messages. Problems get reported by text. When a dispute arises, someone inevitably says "it's all on WhatsApp."

WhatsApp records are problematic in adjudication for several reasons:

• They're not structured. Relevant messages are buried in hundreds of irrelevant ones. Extracting a coherent timeline from a 6-month WhatsApp group is time-consuming and expensive.
• Context is easily lost. A photo in a WhatsApp message might show a problem. But without the location and date clearly linked, its evidential value is limited.
• They can be deleted. Either party can delete messages. An adjudicator knows this. Records that can be unilaterally destroyed are inherently less reliable than records in a system with an audit trail.
• They mix personal and professional. Disclosure often drags in jokes and comments that don't help your case. I've seen a good delay claim undermined by a WhatsApp message from the foreman saying "not much happening today" on a day the sub was claiming full disruption.

Use WhatsApp for communication. Don't rely on it as your record-keeping system.

The GPS and timestamp requirement

Modern adjudication practice increasingly values digital records with embedded metadata. A photo with GPS coordinates and a timestamp in the EXIF data is far more credible than one with a handwritten date on a whiteboard in the frame.

GPS and timestamp data proves 3 things at once: where the photo was taken, when it was taken, and that the photographer was physically present. That's exactly what an adjudicator wants.

For M&E subs, this means your site team's phones need location services enabled when taking photos. You also need a system that preserves original metadata. If photos get compressed or re-saved through certain apps, EXIF data gets stripped. Your record-keeping system needs to store the originals.

The same applies to digital diary entries. A record created on a tablet at 17:30 on site, with GPS confirming the project address, is far more credible than a spreadsheet entry made the following week from the office.

How long to keep construction records

Under the Limitation Act 1980, simple contract claims can be brought within 6 years. For contracts executed as a deed, which many construction subcontracts are, the period is 12 years. You need to keep your project records for at least 6 years after practical completion. Preferably 12.

For M&E subs on buildings with ongoing maintenance obligations, it's more complex. Defects claims on mechanical and electrical systems can surface years after completion. If the heating system fails in year 5 and the building owner claims defective installation, your site records from the installation period are your primary defence.

The cost of proper site records is trivial compared to losing a dispute without them. Ten minutes a day for the diary. Five minutes for labour allocation. Photos as you go. If your site team does this consistently, you'll have records that survive any adjudication. If they don't, you're hoping you never end up in one.