Damp patch inside window

29 Jan 2011
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United Kingdom
Had new windows fitted just over a year ago

Had no end problems with the "installer" (but that's another story)

A few weeks back a small damp patch appeared in the bottom corner of 1 window. Renewed silicon outside and all was well for a couple of weeks.

Last night it re-appeared, does anyone have any ideas ?

Dreading the thought that the window will have to be removed and re-fitted but if that's the only option...........
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Do you have leaking guttering above or an overflow from a cold water tank with faulty float valve?

No water tank overflow

Not sure about the guttering, it did leak previously but we ad that fixed

Could it be running down from there and in top of window then ? ( the window is ground floor living room)
A lot of damp issues are caused by faulty guttering. Which is normally an easy fix, as long as you don't mind using a ladder.

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This is a common problem in which the frame may have to come out. Basically when the rain drives into the window it goes into the gap between the window and the cill and makes its way to the ends of the windows, there should be a bead of silicone applied in a u shaped on the cill before the window is installed, this then stops the rain making its way on to the plaster line. Resiliconing the outside won't prevent this, if you can try and pump some silicone into the corners, this will then stop the rain reaching the internal walls.
A simple 3 second job to do, yet a lot of fitters don't do it!!
Heavy condensation will result in water running off sills, do you have ventilation in the room.

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