Damp exterior walls in conservatory

chocolate.chip

Hi
We moved into our current house a year ago. At the back there is a single brick extension that leads to decking in the garden. Today I noticed that our decking is rotting where it touches extension wall. It certainly wasn't like this a couple of months ago as decking was being oiled and I would have noticed. Exterior walls are also looking wet in places at low level. Interior walls seem dry. Can someone please advise what could be causing this, is that raising damp and who should I contact to have a look at this: builder or damp specialist? Thank you.

Aylesbury_Duck

Some pictures would help, along with some orientation, i.e. which compass point does the wall face?

Doozergirl

Yes, pictures will help but the decking shouldn't be touching the wall of the house. Just simple rainwater will hold between the wood and wall. The wood won't be able to dry out and the ends will start to soak up water like a straw.

You will probably have a cavity wall on the conservatory which is designed not to transfer damp through to inside (especially if it has no insulation), but the decking is likely to be breaching any damp proof course.

If it's rotten now, it would have been well on the way a couple of months ago. These things do not happen overnight.

You don't need a damp specialist. There is always a cause and it's likely to be the way things are laid, not that wooden decking lasts forever.

chocolate.chip

Thank you for replying.
Garden is facing north east. I can't post photos, parts of beam by the wall are normal solid wood but some places are like a sponge- I can poke my finger through also corners by the patio door are affected so Doozergirl is probably right and it's just places that touch the wall and shouldn't that are affected. So could it be just a matter of replacing damaged beams and putting them in correctly? I was worried that it's the other way round and wet wall is affecting the decking.

Doozergirl

Give some good clearance away from the wall so nothing can build up next to it.

The wood isn't going to last forever, but soaking it isn't going to help it, or the house, more importantly.