Around 2,500 workers are set to lose their jobs at builders' merchant Travis Perkins.
The company, which also owns Toolstation and Wickes, said the decision comes as it expects the recession to hit the trade for at least two years.
"Reflecting the challenging outlook for our end-markets, the Group is taking regrettable but necessary actions to preserve the future competitiveness of the business," Travis Perkins said in a statement to investers.
Bosses plan to close 165 stores - mainly focusing on smaller Travis Perkins sites - also they said there were encouraging signs that building work is returning.
"While there has been a significant recovery in trading volumes in recent weeks, it is evident that the UK is facing a recession and this will have a corresponding impact on the demand for building materials during 2020 and 2021," the company said.
Travis Perkins explained volumes in May were around 40% lower than the year before, although they improved as the month went on.
There was also particular strength in Wickes' core DIY ranges and in Toolstation - with both businesses actually improving on their 2019 performance.
Chief executive Nick Roberts said: "Whilst we have experienced improving trends more recently, we do not expect a return to pre-Covid trading conditions for some time and consequently we have had to take the very difficult decision to begin consultations on the closure of selected branches and to reduce our workforce to ensure we can protect the Group as a whole.
"This is in no way a reflection on those employees impacted and we will do everything we can to support them during this process."
