damp ground floor flat and around windows - help needed! Damp can be a major issue in the home. Find answers to questions or post your own here.

[clarkatroid]

hi guys any help on the best way to proceed much appreciated

these pictures relate to one room only, which is the main problem, a gable end bedroom

ive had a humidifier in there for a month now and the damp is responding . it has contained and shrinked the problem quite a bit.

theres 2 windows, one window is fine, which the tenant has the vents open, the other is pictured. the window vents are closed on this window which is annoying as I keep telling her to keep them open but hey ho its a tenant . most of the damp is under one window pictured

ive had envirovent in which quoted me 1600 pounds and told me it was a circulation problem in the flat. ive had a damp specialist in who quoted me 1000 pounds for a mixture of vents and chemical injections.

I have no idea how to proceed to tbh so any advice appreciated. atm my course of acton is to check the cavity wall isn't full of crap, and install some vents.

barring any more advice ill probably re build the internal wall with and membrane under it but I really don't want to do this if I don't need to, so any advice much appreciated

[welsh brickie]

unfortunately the plaster needs removing and the walls tanking with a waterproof sealant, chemical injection wont work as the damp will only move to other areas.
Its best to seal the whole wall to stop damp re occurring

[clarkatroid]

unfortunately the plaster needs removing and the walls tanking with a waterproof sealant, chemical injection wont work as the damp will only move to other areas.
Its best to seal the whole wall to stop damp re occurring

thnks welsh brickie

what tanking process and products would you recommend pls.

strip off plaster, then slurry it?, or use a membrane, or both?

ive not done this before so any help appreciated