Ibstock, the UK's largest brickmaker by volume, has cut its profit forecast after sales fell sharply in the third quarter.
The company now expects full-year adjusted earnings before interest, tax, depreciation and amortisation (EBITDA) in the mid-£40 million range.
It said second-half performance would be materially below its previous expectations.
Industry figures show UK brick sales fell by about 17% in July and August compared with a year earlier.
Ibstock's own brick sales in the quarter were 22% below expectations, and weak conditions continued through September and October.
The company has cut production by about 20% against the plans it set out at the half year to avoid building up unsold stock.
Running its factories below capacity means fixed costs are spread over fewer bricks, which Ibstock expects to reduce EBITDA by about £6 million.
That comes on top of the hit from lower sales.
Ibstock kept its share of the brick market steady during the quarter, and prices were broadly in line with expectations.
The company blamed part of the weakness on the government's delay to Your First Home, a scheme to support first-time buyers, until April 2027.
Joe Hudson, chief executive, said the scheme was encouraging but its timing could weigh on demand in the meantime.
Ibstock is cutting overheads and discretionary spending and keeping tight control of stock and investment to protect cash.
It said its land holdings, including calcined clay, a low-carbon cement ingredient, would help it reduce debt.
A new ceramic façades factory at Nostell, West Yorkshire, is due to finish commissioning by the end of the year.
