Howden Joinery, which has depots across the Black Country, Shropshire and Staffordshire, saw revenue fall 29 per cent to £453.4 million.
Overall group revenue was down from £652.6m a year before to £465m
By quarter, Howden Joinery UK revenue was 1.1 per cent higher in the first quarter and 55.9 per cent lower in the second quarter.
The group went from half year pre-tax profit of £78.1m to a loss of £14.2m.
Chief executive Andrew Livingston said: “Howdens performance in the first half of 2020 was materially impacted by Covid-19, with sales for the period being significantly lower than last year. The shortfall in sales all occurred in the second quarter, which coincided with the start of lockdown in the UK, and led to us making an overall loss of £14m in the first half.
"Our performance improved period on period in the second quarter as we found ways to reopen for business safely and with full stock availability. UK depot sales in the first four week period of the second half were up two per cent year on year.
“During the period our first priority has been the health and wellbeing of our staff and our customers, whose ability to work was curtailed by lockdown. We introduced new ways of operating, provided new services to support our customers during this difficult time and reduced cash expenditure, whilst protecting essential areas.
“Given the Covid related and other economic uncertainties, we remain cautious about underlying market conditions, however we believe a more challenging and demanding marketplace can play to the advantage of our in-stock, local model.”
Howden, which has 732 UK depots, began a phased reopening of depots, manufacturing and distribution in late April. All sites are now open and operating safely.
During the course of 2020 it plans to open around 20 depots in the UK and France and refurbish around 30 older depots to a new format during the year, 18 of which were completed in the first half.