Ann Field watched her husband Harry paint over the tags on their wall yesterday.
It was the fourth time in the past couple of years that their Kamo property has been targeted.
Mr Field was taking the rubbish out yesterday morning when he saw the latest lot of graffiti on their wall.
"It seems as if these guys are having a great time at everyone else's expense," Mrs Field said.
"We have worked hard to get ourselves a home, and they're out destroying somebody else's property."
Mrs Field said her husband is not up to this sort of stress anymore, and the paint used is expensive for the pensioners.
The couple were away on holiday 18 months ago and their daughter was minding the property.
When they arrived home she had told them their house had been "paint-bombed" - covered in paint which looked like it had been shot from pellets in a paint-ball gun.
The paint went all the way up their driveway and along the side of their house.
"It is so sad. If these people can think about going out and buying these cans of paint and using their hands to do this kind of thing, that they call their art, then they should be using their heads to help the elderly, not ruin their homes," Mrs Field said.
Their neighbours' fences and driveways have been tagged on other occasions, and Mrs Field puts it down to long smooth surfaces like their garden wall.
Mrs Field said the CitySafe-operated service D'Tag have visited and covered up some tags, but said they do not have paint to match their wall, and Mr Field ends up having to cover it up anyway.
The Fields have reported the crimes to police but no charges have been laid.
Police communications manager Sarah Kennett said if people see a graffiti incident occurring they should contact the police. They can also report historic instances of graffiti to police as well as CitySafe on 0800 258 258, which is a 24/7 call centre. CitySafe refers the graffiti to the D'Tag contractors for removal.
Planting a hedge, installing lighting and video surveillance, removing the graffiti straight away and knowing your neighbours can all help, police said.