The Kingfisher-owned DIY retailer and US paint brand Valspar have agreed to pay out to redecorate the homes of customers complaining of an unpleasant smell after using Valspar paint on their walls.

DIYers who used the paint, have likened the smell to cat urine and rotten animals, adding that the scent gets stronger in hot weather and if the windows are open.

Valspar, which partnered exclusively with B&Q in the UK in 2012, says the problem experienced by customers is due to an additive being removed from some of its paint. It says that it has now re-added that additive.

Following the revelations, Valspar and B&Q have said that they will cover the cost of redecoration.

The complaints came to light via a Radio 4 programme, You and Yours, where Charlotte Quine from Brighton said she had redecorated her spare room using Valspar paint but was left wondering what was causing the unpleasant smell. She told listeners: “I assumed a cat must have got into the room through the window and sprayed everywhere. Eventually I moved all the furniture out, washed down all the walls, got some carpet cleaner, but again nothing.”

Ms Quine later saw messages left by other Valspar customers on the company's Facebook page complaining that the paint smelt bad. She sniffed her walls and realised she had found the source of the odour.

When Ms Quine complained, Valspar offered to cover the cost of new tins of paint, suggesting she paint the walls with an alkaline-based sealant, and then reapply the paint. However, she was concerned that this not a sufficient solution and would simply mask the problem.

It has been suggested that the bad smell is caused by a bacterial contaminant in the can of paint, with EU restrictions on solvents and the types of preservatives that paint manufacturers can legally use, meaning that problems like this are becoming more common. 

Valspar, which was bought by The Sherwin-Williams Company in 2016, said: "The ammonia-type odour occurs very rarely and when used on walls that are particularly porous, and where the wall is exposed to excessive heat or direct sunlight. The odour naturally wears off over time."

B&Q has said that any customers affected by this problem should ring its customer service helpline on 0333 014 3098.

It is not the first time B&Q has come under fire for its Valspar offer, with customers complaining that improperly-sealed tins caused thousands of pounds-worth of damage to their cars last year. Diyweek.net has also had a steady stream of criticism about the range in our comments section. View some of these comments here.