Many UK construction sites were shut between late March and early May and the resulting dip in sales, allied to fears of an extended recession, had already led the owner of Wickes and Toolstation to cut around 2,500 jobs and start consultations on closing 165 outlets.
Shares of the company fell 4.5% to 1,170 pence by 0705 GMT.
Travis Perkins said on Tuesday its ongoing restructuring programme would deliver cost savings of 120 million pounds ($157.67 million) on an annualised basis.
The group, which has more than 2,000 branches, stores and sites around the UK, said adjusted operating profit fell to 42 million pounds in the first half ended June 30 from 220 million pounds last year.
First-half revenue dropped 20% to 2,781 million pounds, with a 19% fall on a like-for-like basis.
The company also said the demerger of its home improvement unit Wickes was paused until markets become more stable and predictable.
(Reporting by Samantha Machado in Bengaluru; Editing by Patrick Graham and Devika Syamnath)