During driving rain water permeates the outer Fyfestone blockwork of a gable cavity wall, it then runs down the inside of the outside wall, tracks along an RSJ and drips into a downstairs window. I've stripped out the plasterboard from around an upstairs window and, with an endoscope camera into the cavity, can see water running down the inside of the external wall.
Although the Fyfestone pointing appears very sound, a few vertical joints were found to have little mortar behind the outside mortar skin after experimentally grinding them out. Following repointing these joints the water ingress has improved but not completely. I believe a few remaining poor vertical joints are still letting water in, but finding these dodgy vertical pointing joints has been very hit and miss.
I am reluctant to do a complete repointing job for a handful of poor joints, which look perfectly sound until you cut into them. I am now exploring carrying out a smoke test into the cavity to see if I can pin point areas of water ingress.
I would be most grateful if forum members could advise of any experience they have had of cavity wall smoke testing? I understand that a smoke test will seek and display cracks in pointing but would it show up porous pointing?
Any advice would be most greatly appreciated.
Although the Fyfestone pointing appears very sound, a few vertical joints were found to have little mortar behind the outside mortar skin after experimentally grinding them out. Following repointing these joints the water ingress has improved but not completely. I believe a few remaining poor vertical joints are still letting water in, but finding these dodgy vertical pointing joints has been very hit and miss.
I am reluctant to do a complete repointing job for a handful of poor joints, which look perfectly sound until you cut into them. I am now exploring carrying out a smoke test into the cavity to see if I can pin point areas of water ingress.
I would be most grateful if forum members could advise of any experience they have had of cavity wall smoke testing? I understand that a smoke test will seek and display cracks in pointing but would it show up porous pointing?
Any advice would be most greatly appreciated.