Tenants are threatening their housing association with legal action amid claims it has left them to live in “squalid” conditions.
People living in Tempsford Avenue, Borehamwood have accused Affinity Sutton of failing to tackle the mould that has been blighting their 1950s houses.
Liliana Marques, 34, and her husband have been forced to share a room with their nine-year-old son, who has learning difficulties, after an entire wall of her bedroom became covered with mould.
The fungus began to appear in October and last week heavy rain caused water to begin flowing down the inside of the wall.
Mrs Marques called Affinity Sutton, who sent out people to survey the damage but did nothing to fix it.
She has now been told she will have to wait until March 25 for a builder to come round and fix the wall.
The mother, who suffers from repeated attacks of bronchitis and pneumonia and is recovering from a more serious health problem, said her treatment by Affinity Sutton was a “joke”.
She added: “It’s awful the way Affinity Sutton is treating us. They are so quick to attack us when we do not pay the rent but they do not hold up their side of the bargain.
"I can't sleep in my room. I have the windows open all the time, my sister wipes the walls with bleach, which makes me ill, but they say it is my fault.”
Debra Lushey, 50, who also lives in Tempsford Avenue with her partner, has threatened to sue Affinity Sutton after it failed to treat black mould coating a corner of her bedroom ceiling for the past six months.
She said: “These houses were built in the 1950s and are badly in need of repair. I learned they were built on a bog and are gradually subsiding into it."
She added representatives from Affinity Sutton and its contractors CBS had visited to “survey” the damage numerous times but have done nothing to fix it.
She said: “I have to sleep in this room. They have told me not to wipe it away meaning I have to breathe in the mould spores.
“Affinity Sutton blamed my lifestyle for the mould, which they say is due to condensation, but I have been living here five years and have only recently had problems.
“When contractors come round they seem so blasé about the problem, as if they don't care about us and our problems."
Ms Lushey has recently been given an asthma pump by her doctors because she is finding it difficult to breathe, despite never having had asthma. She has also been diagnosed with possible rheumatoid arthritis.
She said: “I know my health problems are linked to the conditions I’m living in.
“I’ve had enough of waiting for Affinity Sutton to come round and fix my house, I’m going to take them to court.
“It’s not about the money, it’s about the way they have treated us. I’m like a pitbull, I will not let go.”
A third house in the street,lived in by a mother and her young children, has black mould coating the bathroom ceiling and framing the bedroom windows.
A spokeswoman for Affinity Sutton said: "We are in communication with the residents of Tempsford Avenue regarding the occurrence of mould in their homes.
"While this is a very common household problem at this time of year we of course understand the inconvenience it can cause and will be working hard to resolve the issue.
“We will also make sure the residents are aware of the simple measures they can undertake to reduce the condensation which has led to the mould growth."