Damp-proofing a Party Wall

by: The Party Wall Surveyor


In April 2009 I commissioned a survey and received the report recommending front, back and party wall chemical damp proof injection. On the 1st May I sent a notice of proposed works to the adjoining property, the neighbour failed to respond within 14 days putting us in dispute. He telephoned me on 16th May to outline some issues he had. He stated that ‘my’ damp had penetrated his side of the wall. He said that he had his side of the wall injected some time ago and still having problems thanks to me and my damp. This was a difficult conversation, especially when he emphasised his vast knowledge of construction technology and building regulations. I have since considered his attitude and note that no consent was sought for his work to the party wall. 

Could you please advise me as to the position of a damp party wall, is one person liable for both sides? 

Will you please outline procedure and charges to draw up an Award to enable me to carry out the damp proof injection.


Injecting a supplementary damp-proof course to half of a wall would be pointless – the damp would just rise around it (if it is rising dampness). This is why your neighbour’s earlier works were not successful. Party walls don’t have ‘halves’, each owner is entitled to make use of the whole of the wall. You are therefore entitled to drill in to the full width of the wall to inject a damp-proof course (subject to serving notice of course) although it would be tricky to go any further than say ¾ of the way in without risking damage to the finishes on the opposite side. I would suggest that you either look to do something jointly with your neighbour or look at other damp-proofing options such as tanking. Injection tends to be the default option for most damp-proofing contractors and is rarely the whole answer. 

To answer your final question – now that you are ‘in dispute’ under the Act your neighbour must appoint a surveyor. You have to write to him again asking him to do so within 10 days, if he fails to do so you will have the right to make the appointment on his behalf. 


Thank you for your email. I have met with the neighbour and unfortunately is extremely hostile. I will now investigate ‘tanking’ the wall.