The firm also revealed it is actively looking to increase capacity by importing cement.
Although it warned that this could prove difficult in the current circumstances because the increase in demand was global and shipping availability was poor.
In a statement to customers Andrew Simpson, packed products director, said: “We implemented a packed cement allocation in May and calculated the number of daily loads per customer based on the production and distribution levels that we believed were achievable.”
He added: “Our own concrete business has been subject to the same allocation.
“Regrettably, we have been unable to maintain those levels. We have therefore taken the decision to reduce the allocation.”
Simpson added: “We will closely monitor these levels in line with our capabilities, and release the restrictions as soon as possible.”
The cement market has seen a demand increase of around 30% across all sectors since mid-2020.
The news of fresh allocation cuts came as the Construction Leadership Council called for greater transparency around rationing policies amid fears that smaller firms were suffering in the face of greater buying power among main contractors.
A joint statement from John Newcomb, Chief executive of the Builders Merchants Federation and Peter Caplehorn, chief of the Construction Products Association, warned: “There is evidence that those who can buy in advance and in large quantities are having fewer problems at present than SME builders who are used to buying the products they need that day from their local merchant.
“The surge in demand means some SME builders are not able to purchase essential materials, like timber, cement and roof tiles, as readily off the shelves. This not only impacts their ability to complete projects, but also the cash flow of their business.
They also urged customers and manufacturers to work more collaboratively.
“For example, customers should not over-order unnecessarily, while manufacturers should not promise delivery dates that cannot be achieved, only to cancel at short notice.”