Damp in my garage from neighbours garden?

[propertystress]

My partner and I moved into our property exactly a year ago. Throughout the autumn/winter we noticed a lot of damp in the back half of our garage (it’s a tandem so quite long) on the wall that sides with our neighbours garden. Now the summer has come it has dried out significantly but you can still see where damp has been (see attached photos) which makes me think it’s been an issue for much longer than we’ve lived here.

We’re interested in partially converting our garage but obviously need to fix the damp issue. Our neighbours have had their house up for sale since autumn last year, so thought I’d check their advert pictures to see if there was anything obvious in their garden that could be causing water ingress. Their raised lawn area is retained with sleepers that butt up to the corner of the garage that is affected and they also have a metal shed, the roof of which slopes backwards towards our garage wall and I don’t think there’s any guttering on it (see attached pics).

Several questions. What do you think is the main cause of the water ingress? How can we approach the neighbours about it, if it is something in their garden causing the problem? And is there anything we can do ourselves to prevent the damp i.e. tanking inside or using damp seal on the outside wall?

 

[jj4091]

If you are going to get a builder in to estimate for you garage conversion then ask him his opinion about the damp.
If he agrees with you that it is caused by the neighbours landscaping/shed then approach them politely and explain what the builder has said and that you would appreciate it they could resolve the issue so that you can get your project done. But do it quickly because as far as I am aware it is not possible to sell a house if there is an on going dispute with a neighbour. So it will be in their interests to get it sorted quickly.

 

[23vc]

Guessing their block paved patio may have bridged your dpc if there is one. Also, worth checking your roof to ensure there’s no water run off on that side. Might have a load of debris on it from trees, stopping it draining elsewhere. Bottom area of wall very visibly water affected on the outside…

 

[Ivor Windybottom]

You've got a severe damp issue there. Even without the conversion, that's a big problem even for a garage. Bet all your tools stored in there are rusty. Eventually the roof woodwork will rot if it stays like that.

I'd be telling the neighbour there's a major issue with damp and asking for a look at what's on their side.

It probably needs a retaining wall to hold the soil back from your garage. It's their problem, but of course the friendly apporach would be best at first - at least until they refuse to fix it once they know there's an issue.

 

[Ivor Windybottom]

Good news if they're dickheads and it's for sale though... the new owners at least won't be the same people who decided it was a good idea to mound a load of soil against your building and will be able to claim money back from them for the cost of putting it right if you'd already told them it was an issue and they hadn't fixed it.