After extensive rebuilding of existing property and extension to property 2 years ago, the chimney in the new extension has regularly developed water stains on the chimney breast and ceiling where chimney goes through the roof (no loft). The original builder/roofer of the extension has been back to check lead flashings and tiles but found no problems, I siliconed the joints in the lead flashing, problem continued (after sanding plaster and sealing internally each time once dried out). Got out a second roofer for second opinion but he found chimney and roof well constructed and believed problem was because chimney had no damp course, but said this was not unusual, but the bricks were saturated causing water penetration into bedroom chimney breast below and problem could be fixed by spraying bricks with weather shield once they dried out. This was done in February this year and seemed to have sorted the problem - until we've discovered again it has returned in the last couple of weeks after heavy rain.

The other chimney which was rebuilt within the original property has no such problems. However the angle the new chimney sits on the roof is quite acute and the last roofer said the chimney is more exposed than the other one.

Do you think we should take down the chimney and have it re-built with a damp course and if so how much do you think it will cost to sort - the chimney extends 4ft above the roof tiles and is approximately 3ft x 18" approx. We've never claimed on home insurance but in your experience would this be covered on most policies?

Would be very grateful for any help and advice on this problem as now run out of options.

once had man get me to replaster his chimney cos it leaked like hell, after chipping off the render i was shocked by how saturated the blockwork was. never seen like of it. but problem turnd out to be the concrete cast that sat on top of chimney had a slight crack in it and cos his house was quite exposed it got soaked regulary it never got chance to dry. cos the chim was at side of house and quite tall top wasnt visable and it not usually were leaks come it took him while to figure it out. he ended up puttin a lead cover over the top cos the thing was so high and the cast was massive

Thanks for info, hadn't considered chimney cap, but can't see any other problem so will investigate further. Many thanks

Yes - from your information it is starting to look like it could be the concrete cast. We have heavy snow at moment (rural Lincolnshire) so have been unable to get the second roofer back out to look at again. Don't know if he or other 2 original roofers had checked cast so will post again once roofer has been back. Many thanks - very helpful.