Hi, I'm really at the end of my tether here, so i'd appreciate any help you can give. Sorry the post is a bit long. please help!
About a year ago I had my old sash windows replaced with new double glazed timber sash. I had the whole box replaced, not just the sash itself. The company were local, FENSA registered and easy to deal with - all seemed ok.
About 8 months later, in the first floor bedroom, I started to notice small darker patches on the wall, under the sill. I got a builder round, he checked all the sills on the outside with a spirit level, checked all the seals where the new sash box meets the masonry and checked the guttering and roof above. All were fine. He said the water must be coming in through the new window and he cannot find anywhere else that water could be coming in. Also - he's no expert on windows, but he was very surprised at the design of the sash which has a draft brush strip on the outside of the window. The brush strip slots in through a tiny channel. He thought water is coming in that tiny slit.
I got the Window company round. They said they fit 90 of these boxes a week in London and had never seen any damp or water coming in before. They said the box is a sealed unit, so even if it was coming in the channel that the brush strip slots into, it wouldn't seep out into the wall. They said it wasn't damp, it was just plaster work that hadn't smoothed out. he redid the plaster and repainted. Heavy rain this weekend, the patches are back..
Basically, i'm at a loss to figure out what to do. No one can find the cause, so i can't find a solution. The damp did not seem to be present before i replaced the windows, so logically, it must be the windows, but i dont' know what to do - short of ripping all of them out and refitting. even then, this might not solve the problem.
any thoughts, please?
About a year ago I had my old sash windows replaced with new double glazed timber sash. I had the whole box replaced, not just the sash itself. The company were local, FENSA registered and easy to deal with - all seemed ok.
About 8 months later, in the first floor bedroom, I started to notice small darker patches on the wall, under the sill. I got a builder round, he checked all the sills on the outside with a spirit level, checked all the seals where the new sash box meets the masonry and checked the guttering and roof above. All were fine. He said the water must be coming in through the new window and he cannot find anywhere else that water could be coming in. Also - he's no expert on windows, but he was very surprised at the design of the sash which has a draft brush strip on the outside of the window. The brush strip slots in through a tiny channel. He thought water is coming in that tiny slit.
I got the Window company round. They said they fit 90 of these boxes a week in London and had never seen any damp or water coming in before. They said the box is a sealed unit, so even if it was coming in the channel that the brush strip slots into, it wouldn't seep out into the wall. They said it wasn't damp, it was just plaster work that hadn't smoothed out. he redid the plaster and repainted. Heavy rain this weekend, the patches are back..
Basically, i'm at a loss to figure out what to do. No one can find the cause, so i can't find a solution. The damp did not seem to be present before i replaced the windows, so logically, it must be the windows, but i dont' know what to do - short of ripping all of them out and refitting. even then, this might not solve the problem.
any thoughts, please?