Damp and tanking

scot22_2

Victorian random stone building converted to flats 1970s.
The Flat above me has two points of penetrating damp.  Usual issues guttering etc are fine.
He intends to tank his walls.
I am concerned water might run down into my Flat below.
I would value comments on problems this tanking could cause.

FreeBear

Outside finish ?

Render, if it is cement or K-Rend will trap moisture in the walls. If not rendered, look at the pointing.

Tanking on an upper floor is a waste of time & money that would be better spent identifying the actual cause. Water can travel quite a distance inside a wall (even a solid brick one), so look for defects up to 3m away from where the damp patches are inside.

scot22_2

Thanks FreeBear for a prompt, clear and very helpful reply.
No rendering but mainly cement pointing, some now replaced with lime.
He wants service charge money, other leaseholders, to pay for it !
Very concerned about damp being spread.

FreeBear

scot22_2 said: Very concerned about damp being spread.

And quite rightly. Any damp will travel until if finds a weak spot where it can get out. So slap a waterproof coating on part of the wall, and the damp will migrate out toe the edge & beyond. Come the winter, if this wall remains damp, the water will freeze causing the bricks to spall. Another problem with a damp wall that doesn't often get a mention - It will suck heat out of a building, and promote condensation.

A damp wall is a cold wall.

scot22_2

Very much appreciated.  May the future bring all you wish yourself.