I've got a mouldy back door (This is not a euphemism…)

[dollywould]

I've been trying to find out the cause of it and drawn a blank, so am throwing myself on the wisdom of MN…

For a couple of months the backdoor of our 'lobby' - essentially a wooden lean-to built on to the back of our house - has been mouldy. It's glazed along the side of the door and the windowframes have been getting mouldy there too. I'd have thought the area is well-ventilated - there are enough draughts blowing through the door to power a sailboat. I've been treating the area with Dettol Anti-Mould spray but it's a losing battle.

We also have a larder in the same area - packets in there get very damp, so much so that our tubs of salt are sodden.

The area has a terracotta tile floor. Our kitchen opens on to it - I wouldn't have thought condensation would have been a problem as we have a connecting door with a catflap. And we use the extractor fan in the kitchen.

It's got a bit more urgent as our washing machine (which is in there) has broken down - the engineer thought it could have shorted because moisture. So would it be ventilation? Or as DH thinks, do we need to insulate it?

All - and any - advice gratefully appreciated. Ashamed to say I'm absolutely clueless…

Thanks Kotinka After 'recent events' I didn't want my back door issues to be misconstrued

Sounds like cold bridging, ie a cold spot causing condensation, I think your husband will need to insulate the lobby.

I am sure piglet john will be along to help soon.

Thanks so much, Kotinka and Alwayscheerful for your replies.

Kotinka, that sounds like an ingenious fix! I'm always up for a bit of gungho DIY. The extractor fan is built into our cooker hood, so I thought it would have taken it out of the lobby. I wonder if the cat flap lets the damp air out though?

I'll try sealing the door with wood hardener - the area needs a make-over anyway, so if it doesn't work, all is not lost.

Clearly, I know nothing about condensation as I thought the fact that it's a draughty door would be condensation enough. Alwayscheerful, I've never heard of 'cold bridging'. I'll look it up and do some investigation. Thank you. And it'll be me doing the insulating Always up for learning new skilz, me.

Part of my research was reading Piglet John's replies on other threads. Why he wasn't mentioned in the New Year's Honours list for Services to Mumsnet, I'll never know. A shocking oversight imo.