Is tanking a job for professionals?

[Scion]

A friend has a garage and the adjoining garden covers the lower 1/3 of the left-hand wall.

Water comes in from the soil through the wall. Whatever waterproofing was there is not working any more. The internal plaster is blown and there's puddles on the floor.

Getting to the outside of the wall is not an option so I've been reading about tanking. Seems like there are a few gotchas although the sites I've read are all companies that can do the work...

Is it best to get a professional in to determine exactly what is required and to do the work, or is tanking a relatively easy thing to get right? I'm happy putting some effort in to do the job but would rather not if it is too easy to make mistakes that mean the fix only lasts a short time.

[tabbypurr]

NT

[Harry Bloomfield]

Scion pretended :

Water ingress cannot be sealed from the inside, pressure will simply lift off any sealant used. It has to be done from the outside.

The only fix on the inside, is to allow it to collect and to drain it away, with a waterproof membrane spaced away from the wall, to provide a dry interior surface.

A bank vault I was involved with had a drain cut all the way around, which led to a sump and a pump.

[RJH]

Much as a cellar conversion. I'd suggest the OP gets a quote or two - should provide some ideas on approaching the issue, and it may turn out cheaper than they expect. I asked on a local forum for recommendations.

I'd consider it quite DIYable, but it has to be done properly, with the right materials.

[Scion]

Thanks for the comments, people.

[tabbypurr]

Draining may be the better option, but lots of old houses have tanked cellars that, while not perfect, are good enough.

NT