Homebase owner Home Retail Group blamed the poor weather during the quarter – from March 4-June 2 – for the performance.
Seasonal products, including timber decking and other outdoor wood features, represented about 40% of total sales.
Like-for-like sales declined by 8.3% to £421m.
"Big ticket sales were also down in a market that continues to be challenging, while sales for the remaining categories were level," it said.
Homebase’s results follow B&Q’s, which showed a 13.8% slump in second quarter retail profits, partly due to a 30% decline in outdoor seasonal products.
