Hi
in my ground floor flat (rented out) there's a damp patch on the lounge wall at roughly chest height. the section of wall is between the lounge and kitchen and would originally have been an external wall decades ago. at some point a kitchen and bathroom extension has been added.
one contractor is saying the cause of the damp patch is most likely a leaking rising main in the wall, however he can only see a small part of it (via ceiling hatch in kitchen and under kitchen sink i think) and would need to break into wall to properly assess he didn't actually see any water or signs of the pipes leaking.
second contractor said he didn't think it would be a leaking rising main, more likely caused by leaking external downpipe that sits in corner where lounge wall meets kitchen wall. he supported his theory by saying that's probably why expanding foam has been injected behind downpipe.
a third contractor (only based on seeing pics though) advises downpipe very likely not leaking and that foam would have been injected to compensate for gap left by smaller diameter plastic pipe compared to cast iron pipe it will have replaced. he advises water possibly getting in through poor pointing or faulty window seal or something.
for information, the damp doesn't start to dry out if there's been no rain for x days, so i reckon it's either a leaking internal pipe e.g. rising main (constant water under pressure) or the downpipe that will have water running through it whenever the flat upstairs uses water and/or when it rains.
PLEASE HELP!! i don't want to instruct a contractor to fix one thing if it ain't broke! based on these pics, what would you reckon is the probable cause of the damp? i've marked it's approx. location and size in black.
any thoughts / advice welcome.
in my ground floor flat (rented out) there's a damp patch on the lounge wall at roughly chest height. the section of wall is between the lounge and kitchen and would originally have been an external wall decades ago. at some point a kitchen and bathroom extension has been added.
one contractor is saying the cause of the damp patch is most likely a leaking rising main in the wall, however he can only see a small part of it (via ceiling hatch in kitchen and under kitchen sink i think) and would need to break into wall to properly assess he didn't actually see any water or signs of the pipes leaking.
second contractor said he didn't think it would be a leaking rising main, more likely caused by leaking external downpipe that sits in corner where lounge wall meets kitchen wall. he supported his theory by saying that's probably why expanding foam has been injected behind downpipe.
a third contractor (only based on seeing pics though) advises downpipe very likely not leaking and that foam would have been injected to compensate for gap left by smaller diameter plastic pipe compared to cast iron pipe it will have replaced. he advises water possibly getting in through poor pointing or faulty window seal or something.
for information, the damp doesn't start to dry out if there's been no rain for x days, so i reckon it's either a leaking internal pipe e.g. rising main (constant water under pressure) or the downpipe that will have water running through it whenever the flat upstairs uses water and/or when it rains.
PLEASE HELP!! i don't want to instruct a contractor to fix one thing if it ain't broke! based on these pics, what would you reckon is the probable cause of the damp? i've marked it's approx. location and size in black.
any thoughts / advice welcome.