Jeff Howell: how can I stop flooding? The rainwater downpipes on houses of this vintage were rarely piped directly into the sewers. The usual solution was a soakaway - basically a hole in the ground filled with broken brick, and sometimes covered with a sheet of corrugated iron, before being earthed over. Over the years, the soakaways silt up or collapse, meaning that the roof water is simply discharging directly into the ground next to the house, saturating the soil. If your subfloor void is deeper than the outside ground level, then it will quickly fill with water. You or your builder can easily check to see where the rainwater is flowing to, by lifting the lid off the nearest sewer inspection chamber, and running water from a hose into the top of each downpipe in turn. If there is no sight or sound of water entering the sewer, then it is most likely going into a blocked-up soakaway. Soakaways can be renewed, using modern plastic cages wrapped in geotextile. But the best option is to run a new underground pipe to carry the water well away from the house - to a nearby ditch, or else cut in to the side of the inspection chamber (above the level of the sewage waste pipes). Out of sight Q: I have just had my guttering, soffits and cladding replaced. I noticed that my overflow pipes for the cold water tank and heating header tank were no longer visible. When I phoned, they told me that the overflows have been put into the guttering, which looks very neat, and when an overflow occurs now it won't splash onto the garage and the cladding. But how will I know that I have a problem if I can't see them overflowing? Is this normal practice now or should I ask for them to be reinstated to how they were before? I trust the firm implicitly but I can't get into the loft to check the tanks periodically and British Gas do not check this as part of their service like they used to. I had the ball cock replaced a year ago but the header tank is the original from 26 years ago. GC, by email A: You say you trust this firm implicitly, but I'd say your trust might be misplaced. They have cut off your overflow pipes without asking permission, and without ever telling you they'd done it, and, as you suspect, this is not good practice. These pipes were originally called warning pipes, and the idea was that they should be situated where any overflow of water would be quickly spotted, so that the cause could be investigated and rectified. The current situation means that one of the tanks might be overflowing for days or weeks without being noticed. This is not only a waste of water, but means that a more serious problem might go unattended. For example, while an overflow from the f & e ("feed and expansion") tank might be due to a scaled-up ball-float valve, it could also indicate a problem with over-pumping, or perhaps overheating of the hot-water cylinder due to a failed thermostat. Similarly, the cold-water cistern might overflow due to a faulty ball-float valve, but this could also be a symptom of a corroded heat-exchange coil in the hot-water cylinder (this can result in overflowing from either of the tanks, depending on which one is the lower). You should insist that the pipes are reinstated so that any dripping will be immediately obvious.