Chief executive Geoff Cooper said the prolonged period of rain affected the heavyside business in particular – a market that was already "struggling to recover to more normal levels".
Despite this, the company’s four divisions continued to take like-for-like market share, he said.
Travis Perkins’ pre-tax profits rose to £137m on revenue up 2.7% at £2.41bn.
Merchant market volumes fell by 4%, although housebuilders reported better prices and forward order books for new build. However, in consumer markets, volumes were down by at least 10%.
The company’s outlook for the rest of the year is unchanged as it expects its gross margin and overhead actions to mitigate the slightly weaker market volumes.
"Our focus on improving operating margins and increasing return on capital has been rewarded during the first half and we believe that it will enable us to continue to outperform our overall market for the rest of the year," the company said in its trading statement.
