Damp patch on conservatory brickwork
Our house was built in 1971 and a conservatory added 10 years later. We have now noticed above the conservatory there is a huge patch of brickwork which never dries out. I don’t know how long because an observant neighbour informed us. What can it be? There is no sign of anything inside the house.
- It's unlikely to be anything to do with the conservatory as this isÿnearly 30 years old.ÿIt sounds more like a failure in the main house guttering or perhaps a leaking downpipe. Even so it's surprising that it never dries out but possibly it's a north or east facing elevation or otherwise sheltered from drying sun and wind.ÿ
The best advice is to carry outÿsome rudimentary observation and detective workÿover the next few monthsÿ- this should start toÿreveal the answer to the conundrum.ÿ
The fact that nothing is visible on the inside proves the value of modern cavity wall construction.ÿÿ
I have a brick built miners cottage which is approx 100 years old and is rendered on the front elevation. There is a 100mm spacing between the bottom edge of the rendering and the pavement outside.
The inside walls have what appears to be a 1 metre high cement mixture rather than plaster and at the base about 500mm apart are small round vents about 30mm in diametre which have tubes behind them going into the wall. I have a Royal Doulton Damp Proof Certificate from approx 35 years ago and assume that the vents are to do with this. However I am about to refurbish the rooms and wondered if there was a way to remove them for something more modern as they prevent wallpapering or if after all this time I needed to conduct any type of maintenance on them to maintain damp proofing. There does appear to be salt marks (white powder) on the walls, which I have scraped off, they walls are quite uneven so I would like to plaster and repaint but would not want this staining to come back through
How can I tell if the house has condensation problems or it is rising damp ?
I had large patches of damp appear after having some standard plastering done. I then had a damp survey done by a specialist surveyor and was told the DPC was bridged due to the plastered walls on 3 sides of room meeting directly with the flooring. I was advised to remove the plaster up to approx 2 ft, re-plaster with porous plaster, leave a gap between the new plaster and the flooring and fill with anti damp solution (some kind of spray was used). 3 months later I now have a tide mark under the back window sill (external wall) approx 1 & half feet up from the skirting boards. There are also slight markings around the other walls. Can you explain what has happened?