Can anyone help to explain what happens when we tread on certain floorboards?

[VenetiaLanyon]

When we tread on certain floorboards in the living room, our 2 living room lamps flicker on and off; would anyone have any ideas as to what could be wrong here, what we need to do, and whether this is dangerous?

Thanks

Can only guess that the wiring is lying too close to the boards, you should get a local diy man to check this out maybe. If you have an rcd on your consumer board it will trip out so the electric will go off if there's a serious problem and protect you.

Like Cornish, I guess the wiring is too close to the boards, so that when you tread on them, you're pushing/pulling on a loose wire. The flickering suggests you are breaking the circuit momentarily - the electricity will try to 'jump' the gap you are creating, perhaps causing a tiny spark each time. And sparks under floor-boards are a fire risk, of course...

Thank you; will get someone to check this out

cables should be threaded through holes drilled in the mid-point of the joist. It sounds very much as if some bodger has laid them direct under the floorboards, probably in a notch. This is very bad practice. If they have been laid squashed up against a hot water pipe, usually for radiator pipes, it is extremely bad and dangerous practice, as the cable insulation softens under heat and can be squashed away from the conducting cores and possibly touch each other or the copper pipe.

if you are less unlucky it will be a badly fitted junction box under the floor. It is not permitted to do that as they are liable to loosen over time and should be accessible for inspection and maintenance.

it might also be a nail that has penetrated a cable. again, this should not happen if the cables have been correctly fitted at joist mid-point.

Thanks, Piglet John, that's really helpful detail.