Damp patch on wall below bay window, is this rising damp?
I have a damp patch on the wallpaper below a bay window in my front room. The space beneath seems to be hollow. Is this likely to be due to poorly sealed windows, to genuine rising damp or to something else? Thank you.
- Bay windows frequently suffer damp problems, so your description will sound quite familiar to a specialsit damp surveyor.
If the dampness isÿan isolated patch just below the window cill, then the likelihood is that it's condensation. This isÿquite common in a projecting bay where cold spots can form readily.
However if the dampness starts at skirting board level, it needs examining for the possibility of rising damp.
The other possibility with window bays is penetrating damp as often the brickwork is single skin rather than cavity construction, so you need to check the pointing, the window cill drips and the general sealing between the timber and masonry.
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?