Leaking plastic window frame

SatanicHare

Sounds to me as if the cill has not been sealed on properly, and the water is running off the end and down the cavity. Best solution is to remove anf re-fit the entire window, but not the easiest thing to do. You could try drilling a 6mm hole about 5mm up from the bottom of the frame at each corner, the drill should go through a couple of skins and then hit a void, pump as much silicone as you can in and seal the hole again. I've done this with success to a lot of windows. Best of luck

Lunepilot

Thanks for all the replies,just thought i would give an update.
A friend of a friend who fits windows came round, and removed the inner beading holding glass in at the bottom and sides. The drain holes were ok but he believes there is a problem with the design of the frame on the inside edge it has a channel that holds the bead and seal in, but the lip is only very small and allows water into channel that does not drain quick enough onto cill this then tracks along seal and frame and drains onto wall.Apparently this design has now changed,so solution was to seal with silicone the gap in front of channel and behind glass then refit beading.
So now waiting for heavy rain to see if problem has been solved as leak only occurs during heavy driving rain.
I will Keep you posted

Thanks

168hourweek

Hi
Sounds like a problem with your vertical DPC(damp proof course)

Lunepilot

Yes he did mention that,so that will be the next move if this fails.However as soon as rain stops damp patch dries up and is bone dry if it was vertical dpc would there not be permenant damp? Just to recap there is only a damp patch on wall at bottom corners of window frame with a radius of 100mm.