NHBC warranty query

[chatterbox]

I bought a new-build a few years ago and recently saw what appeared to be very faint water marks from below the skylight. I had already made an appointment for a roofer to come around to fix some downpipes near the roof that were starting to come away from the house by the time I had spotted the leak and asked the roofer to inspect the roof and window while he was here. He stated that the lead flashing around the window had lifted up slightly and said that a mastic sealant may help prevent further leaking until I could get the builder or NHBC to address the issue but couldn't absolutely guarantee it as it was likely that the window hadn't been fitted properly. As I was already paying for his time he agreed to do the sealant as it was just a few minutes of extra work for him. The sealant hasn't made a difference and water is still coming in, but I'm now unsure if this invalidates my warranty? The roofer was a qualified roofer and there wasn't any amendments or extensive work performed, just literally a sealant applied. The warranty states that it doesn't cover work performed by anyone else... but the leak isn't a result of any work performed. Surely this falls in line with adequately maintaining the property which is also mentioned in the warranty?

[Sam101]

Possibly, as some work has been done by you. However, it could be argued that you have tried remedial work as it seemed to be only the flashing and did not wish to inconvenience the insurers, Suggest you make a claim without mentioning the efforts you have made and see what happens and as long as what has been done has made matters worse with the fault, then it may be OK and be repaired correctly under the guarantee.