"To date we have been satisfied with the process being applied but during the course of today we have become increasingly concerned with the position.
"This concern has been borne out by a number of tests carried out that indicated the possibility that asbestos dust exists outside the fenced area of works."
Testing by Work Safe NZ last night confirmed asbestos within the fenced area, however further testing was needed to confirm that the area outside the fences was asbestos-free.
That testing is due to be carried out today, and while it may ultimately show that the site was safe, board representatives stated they were not satisfied with the school remaining open until that could be proven.
It was likely the school would be closed until Monday at the earliest, school representatives said.
A meeting with parents to discuss the issue was being planned. Board members were due to meet with ministry representatives this morning to obtain health and safety information that could be circulated to parents.
Bayfield School is a decile 10 school with around 380 Year 1 to Year 6 students.