Damp getting me down

Phil4432

Way too much for condensation.
You have a leak somewhere.  Sound like the overflowing gutters, causes long term damage somewhere.  If the roof, gutters are now ok perhaps its a pipe in the loft? 

Oren

OK, I so got up there today to have a look at how I could get to that side....
I'm mostly blocked by the water tank as you can see from the pic. I'd have to go (crawl!) around the side of it.... Gonna need to get me some board or planks, though I'm not as small and nimble as I was when I was a teenager! No light up there either, so sorry for dark pics. 
You can see the insulation. I remember the survey we had done saying it should be thicker.
It's cold and a bit drafty up there but I didn't smell any damp or see/feel condensation from where I was. Doesn't appear to be any leaks coming from the tank or any pipes near it. 

Oren

Also I forgot about outside pics, will take some! 

troffasky

Appreciate the effort with the pictures, but if the damp is localised to one part of that room, then ideally we need a picture of just above where the problem is, and I am assuming that would be right down in the corner.

Without wanting to extrapolate too much from the pictures, your loft doesn't look damp [mine has bits of white fuzz under the felt] to me.

Oren

@troffasky Yes it's just working out how to get there to take a photo.... I thought I might see something obvious from a distance to help, but unfortunately not

twopenny

Selfie stick? There's bound to be something to use.

When I couldn't work out where a dripping sound was coming from (night and heavy rain) I put plastic sheet under the area with the idea that I could see if there was a leak or not.

There wasn't. It stayed dry. Never did find what made the noise over years which is just as annoying.

Paper towels laid down would show drips or if there's a lot of damp up there. Looks dry enough though. I'd be inclined to think it's where you've had the replacement. The wall was damp, the moisture can't escape outside  so it's escaping inside. Possibily because it's a lot warmer in the room with heat rising and it's drawn the moisture into the dry air.

Jeepers_Creepers

Selfie stick is a good idea. You can also buy 'endoscope' cameras to plug in to your USB - fix that to a long stick and get right in there!

Oh, and tie up your tank lagging while you're there :-)

Jeepers_Creepers

I doubt very much that this is residual water from the old guttering problem as suggested earlier - there's just too much water still there.

I suspect, tho', that a builder/roofer will quite easily find the source of the problem from outside from a ladder; I think it'll be something pretty obvious at the end of the day, tho' it could be coming in far higher up the roof and only coming in to the house at that corner.