New homes have been built using sub-standard mortar, meaning housebuilders have been forced to carry out remedial work.

BBC news reporter Victoria Derbyshire reported  last week that homes on at least 13 estates in the UK have been built with mortar that does not meet the industry standard outlined by the National House-Building Council, which provides warranties for new homes.

Under NHBC guidelines, mortar in most areas of the UK should be made of one part cement to 5.5 parts sand. In severe weather areas, there should be even more cement in the mix to make it stronger and more durable.

Vincent Fascione (pictured), 70, lives in Coatbridge, near Glasgow. He told Derbyshire that one evening in 2016 he heard a loud cracking noise from the external walls of his new build house. The next morning he saw a sand-like substance on his front path and driveway, with cracks appearing in the mortar holding the bricks together.

Fascione said that samples from parts of his home were tested and the amount of sand was almost three times higher than recommended. He said that, after 18 months of complaints, the NHBC bought back his home and he is now living in alternative accommodation.

The NHBC has apologised in a statement to the homeowners who had experienced problems, and said that it “cares passionately about the quality of new homes”.

It added: “As a warranty and insurance provider, we work with builders to help them improve the construction quality of the homes they build.

“However, it is the builder who is ultimately responsible for the quality of the new homes they build.”

Taylor Wimpey has agreed to replace the mortar in more than 90 properties in one estate in Coatbridge, but emphasises that this is a very small percentage of its overall number of properties.

The housebuilder said its suppliers carry out quality assurance tests on all the mortar it uses, and there are “very few” instances where it falls short of standards.

It said: “While a significant number of houses on the development are unaffected by mortar issues, a robust technical solution supported by an appointed structural engineer and the NHBC to fix the durability of the mortar has been identified and homes are being remediated as soon as possible.”

It apologised to customers who had been affected by this issue.