UK Construction and Law

11,579 files on a hard drive, and a rival bridge formwork business is held liable

By Staff Writer  |  31 August 2026

A maker of permanent glass reinforced plastic formwork for bridge decks sued two former managers and the joint venture company they set up with a composites group. The High Court disbelieved the account of how the files came to be copied, held the CAD drawings and calculation summary sheets confidential, and found a senior manager in breach of fiduciary duty for not reporting his own plan.

Permanent formwork is a product most people on a bridge job never think about twice. Moulded panels of glass reinforced plastic are set beneath a deck, structural reinforced concrete is cast on to them, and they stay there as part of the finished structure. There are not many firms in the country making it. A judgment handed down on 17 August explains how one of them lost its drawings, its calculation sheets and its customer list to two of its own managers.

The senior of the two ran the operations side of the business for most of a decade and left in April 2022. During his notice period he copied files on to an external hard drive. The number was not in dispute: 11,579. Three years later he and a colleague, with a composites group holding half the shares, were competing in the same market.

The explanation the court did not accept

His account was that a director had asked him to take the copy, as a precaution against another director walking off with the company's information. The court did not believe it. The information sat on group servers abroad, so it was never explained how anybody could have walked off with it. The meeting at which the request was supposedly made was on the wrong date. Files were copied on days before that meeting had happened, and again ten days after he had said he was used as a pawn by the very director he said had asked him. He also emailed himself the company's pricing for two projects more than a year after leaving.

The court found the copying was for use in a competing business, and that the story about the request was invented to explain the drive away.

What was confidential, and what failed

Two categories mattered. The first was CAD drawings. The court found the new company's drawings were created from the claimant's, and rejected the argument that because the claimant had received the rival's drawings from contractors in the industry, its own drawings could not be confidential.

The second was calculation sheets. Formwork is safety critical, so detailed structural calculations are kept. The underlying spreadsheets were not in issue, because the evidence about them came too late to be admitted. What was in issue was the one page summary sheet generated from them. The court found the text on the rival's summary sheet was copied from the claimant's, on similarities too numerous to be coincidence or memory, and that although such sheets are shared with customers, they are shared in confidence. So the sheet was confidential.

The copyright claim failed, and it failed on the pleadings. The claimant identified the drawing but neither pleaded nor evidenced subsistence or ownership of copyright in it. The court doubted this made any practical difference, because the same facts established breach of contract and breach of confidence.

The fact that it was his own plan makes no difference: it merely means that he was obliged to report himself.

Recorder Douglas Campbell KC, sitting as a Judge of the High Court

The fiduciary point

The senior manager was not a statutory director and had no access to financial information. The court still held he owed fiduciary duties. He was the person running operations on the ground, he reported to a manager who was not based on site, he reported to the board from time to time, and he was working ninety hour weeks. If he had found an employee copying documents to compete, he would have had to tell the company. He did not escape the duty because the employee was himself.

The junior man was cleared of removing material, but his use of a December 2022 list of commercial prospects for the new company's business plan was a breach of contract, of confidence and of his settlement agreement. Both were held individually liable for the February 2024 marketing emails, which reached contacts at addresses that were not publicly available.

Additional damages are in play. The court accepted the defendants were fully aware their acts were unlawful and had merely hoped they would not be found out. The action succeeded and relief will be argued separately. Anyone running a small technical business should note where the case was won: not on the covenants, which had long expired, but on the confidentiality clauses, the handbook, and the drive.