Need to hard prune wisteria - help!

[garden numpty]

We have a damp patch on our chimney breast which we suspect is due to the overgrown wisteria on the wall outside. This house is new to us and I've done the August prune but with the damp patch as it is I don't think we can wait until January/February to hard prune it. It's difficult to tell at the moment just how much will have to be cut out but I suspect it will need a fairly severe hack.
What will happen if we do it now instead of waiting?

Never done this before - all advice appreciated

[Jardiniere]

i've never gown a wisteria - but the house opposite me had one growing on the roadside verge and it reached way up into the trees up on the cliff behind - a few years ago the village handyman cleared the verges and cut the wisteria off virtually at ground level - it has now grown again - miles up into the trees.....so....
dealing with a damp patch could be expensive and a wisteria plant is how much?

[PAULW]

I would be more inclined to checking the flashing on the chimney first with the damp being on the chimney breast, if it was damp on a wall then the wisteria would be the first call.

[vicky]

I don't see a problem hard pruning a wisteria now, I've also seen them cut back to the ground and springing back with more vigour than before! They are pretty tough once established.
Try to keep a nice shape to the 'framework' of the branches if you can, as it'll look better when there are no leaves.

[garden numpty]

I would be more inclined to checking the flashing on the chimney first with the damp being on the chimney breast, if it was damp on a wall then the wisteria would be the first call.

We had a builder check out the flashing etc before we bought the house, although it was only a quick check - I see your logic though.

I think we might do the wisteria anyway in case it is having an effect. I'm just concerned that it might make it send new shoots out all over the place - something i vaguely remember reading.

[annianni]

Hi - I've done mine in Sept before, and am about to again! (August sort of ran away with me....)
It shoud be fine, and be ruthless, and then cut even more - they are amazingly resilient, and will come back better and stronger.
Good luck!