The group posted a 48 per cent rise in profit before tax for the six months to 30 June, at £20.8m, up from £14m over the same period in 2014. Revenue for the period grew by 11 per cent to £199.1m compared to £180m in 2014.
In its interim announcement Marshalls said trading conditions continue to be positive and both order intake and sales growth have been strong.
"If these positive market conditions continue through the second half, noting the stronger comparables in the second half of 2014, it is likely that full year trading will be above original expectations," the announcement said.
Sales to the domestic market (around 30 per cent of group sales) were up 4 per cent on 2014. Marshalls plans to drive more sales through its approved list of more than 1,800 domestic installers, offering training, marketing materials and sales support.
A survey of domestic installers at the end of June revealed order books were at a record June high of 12 weeks, up from 10.6 weeks at the end of April 2015 and up from 11.5 weeks at the end of June last year.
Public sector and commercial sales (around 64 per cent of the group's sales) were up 15 per cent on 2014, with the company outperforming the market in commercial projects in water management, street furniture, rail and new build housing.
Chief executive Martyn Coffey commented: "The Group is well positioned to grow organically and selectively through acquisitions. We will continue to focus on growth initiatives during the remainder of 2015 and in 2016."
The Construction Products Association's summer forecast predicts growth in UK market volumes of 4.9 per cent in 2015 and 4.2 per cent in 2016, Coffey added.
"In order to drive growth, the Group continues to develop the Marshalls brand and invest in product innovation and service delivery initiatives to deliver improved trading margins and increased return on capital employed."