Basement water ingress

[nathdugg]

Last week after very heavy rain there was a small puddle of water on the floor of my converted basement. The basement has one external wall that is 90% below ground level. Though there was one puddle, the water seeped under all the external wall.

The wall and floor have been tanked and there is a stud wall installed. I've recently moved in and nothing was picked up in the survey. I dried the area and assessed outside the property. There is a small private drive ajacent to the basement and it was not in a very good state. Concrete was cracked and there was a neighbours down sprout gushing out water.

I have extended the downsprout away from the property and filled in cracks. There has since been heavy rain but not puddles. I'm hesitent to take out the stud wall to inspect further, but hope the work completed outside will minimise pressure on the external wall.

Does anyone have any thoughts on whether this work would help any further work required, or what to do should the issue come back? Pictures of outside prior to work being carried out (the vent goes into the basement). All rubbish cleared, path recemented and downsprout extended away.

 

[freddiemercurystwin]

Have you any idea how/when the wall was apparently tanked? Directing water away from the outside of the wall is unlikely to solve the problem, though may help, the tanking must have failed in some way. It's your house on the right?

 

[nathdugg]

I'm unsure how it was tanked, however, it was completed last year. On the areas I could inspect, the wall was dry, but that was limited. The water was clearly rainwater. And yes, thats my house on the right.

I haven't had a reoccurance yet, however, I think I will be look to get a professional in to inspect should it happen again.

 

[freddiemercurystwin]

I'm guessing all you have internally to look at is a blank wall with skirting and floor, with no evidence as to how the wall is tanked, if it happens again, they (like anyone on the forum) would need to know how the wall has been tanked, which is likely to involve some exploratory work to expose the tanking. Was this as part of a cellar conversion or something, was it done by a contractor - in which case do you have their warranty?

 

[nathdugg]

There are a couple of vents which I have removed and it looks like its been tanked using a slurry rather than a membrane.

The victorian house was converted in 1998, however, worked carried out last year was for a refurb.

 

[freddiemercurystwin]

OK, slurry's need meticulous attention to their mixing and application and (not what you want to hear) are also useless if the external pressure is just too great to prevent them de-laminating from the masonry. A membrane or drained system is far superior if the pressure is greater or unknown.

 

[nathdugg]

Yea, that's what I have read up. I think my preference is to see if the work outside helps reduce this external pressure enough, however, if it returns, I won't hesitate to look at an internal drainage system.

 

[freddiemercurystwin]

Yep, about all you can do for now .....

Do come back with any further progress etc.

 

[nathdugg]

Will do, and thanks for your help

 

[old duffer]

it's climate change mate...