Damp proofing failure

Hi, just moved into a new house (victorian townhouse) and, despite having a couple of damp specialists around to assess the basement, have discovered that after periods of heavy rain (such as this week) the boiler room in the basement becomes flooded. I am 99% sure that this is groundwater because it has happened twice after periods of very heavy rain and in the the two month period between the two occurances there were no problems.

After investigation, apparently the basement was tanked 7 or so years ago but the company who did the work has since gone out of business and hence the 10 year guarantee is worthless. I suspect that this was why they went out of business.

So it looks as if the tanking has failed basically. My question therefore is: what are my options now to solve the problem and what am I looking at re costs. My major concern is that the basement in all other areas is nicely decorated with large tiles and nice floorboards and I am worried that re-tanking the whole basement will result in major re-decorating.

Can anyone help me understand exactly what re-tanking involves in practice - will the whole floor have to be taken up?

Any advice would be very much appreciated. I feel I have to act reasonably quickly here because I am worried that the joists under the floorboards will be damaged the longer I leave this.

I can attach images tomorrow if this is of any help.

Cheers in advance

HF

Some pics would be nice but a difficult problem to assess online, check the guarantee to see if it's insurance based in which case you could still claim.
Are there any fixing penetrating the tanking, only specialist fixing should be used, ordinary fixings will breech the tanking allowing in water.

Sound like its the water table rising up into your basement.

The old style "tanking" was never a fool proof way of fixing a wet basement as water will always find the weakest point and still get in.

This could be caused by even the slightest movement in the house creating a crack.

Times have moved on and basement science has greatly evolved.

Your problem can be solved quite easy with a perforated sump pump system like the supersump


Simply dig a hole a bit bigger than the system, drill holes in the top quarter of the systems and drop it in. Back fill with gravel (bigger than the holes so they dont fall in the sump) cement upto the top (say about 6") plumb it to a waste pipe and bobs yer uncle...problem solved.