Timber distributors have been urged to check grading stamps carefully by BM TRADA Certification after timber bearing the grade stamp “RS C16” was discovered in Scotland.

BM TRADA said the grade was not usually found in the UK, where SS and GS are the usual classifications.

On investigation, the National Standards Authority of Ireland said the RS grade is produced purely for the Irish domestic market and should not have been exported.

“We are trying to clarify how much timber might be involved and how it has been graded to achieve C16,” said BM TRADA’s Bob Foster. But he said the trail had “gone cold”.

The organisation is concerned that the RS C16 might not equate to a true C16, with evidence suggesting it is more akin to C14.

“If this timber has been used in structural projects, there is cause for concern that it might not be up to the job.”

BM TRADA is urging distributors and contractors to check the grade stamp to ensure it is exactly what has been specified.