Tarmac will close its Suffolk site the end of this month.
A spokesman for the company said: “I can confirm that we have taken the difficult decision to propose that we mothball our factory at Brandon from the end of October this year. Unfortunately, this means all 40 employees at the site are at risk of redundancy.
“The construction industry continues to face extremely difficult trading conditions and we need to respond to these challenges whilst ensuring that we retain a strong core business for the future.”
Tarmac’s concrete flooring business took over the site near Brandon earlier this year.