Damp getting me down

Oren

Hi all.
I live in an end of terrace house built in the 1960s. Over the last year I've been having issues with damp in the top corner of my bedroom, which is at the front of the house - on the end, so not connected to the neighbours. 
Had the gutters cleaned out in February, they were full of crud so I assumed that was likely the issue. However, the problem wasn't solved. Summer came around, obviously no damp. Then a couple of months ago we were having trouble with the gutter bowing and overflowing - our window cleaner clipped the bowed part back up, but informed us that the timber fascias were totally rotten.
Wanting to prevent any issues caused by old rotten fascias, I hired a roofer to replace all the fascias, soffits and bargeboards with UPVC ones. I told the roofer about the damp, he thought it might be exacerbated by a loose roof tile, but he checked the roof above the bedroom and said it's absolutely fine. 
I hoped the fascia/soffit replacements would improve the damp in the bedroom. However a month later it's still there and almost looks worse to me. 
I have a dehumidifier on all day in the room. When I come home from work I discover the damp has dried out throughout the course of the day. The next morning it's right back again.
It doesn't even have to rain for the damp to appear, often after a cold night or on a frosty or misty morning I'll wake up and look at the corner to find the damp coming through. The paint is now flaking off the wall, mould and mildew turns up there which is constantly have to clean off (also wipes off the paint!) 
Can't get into the loft space above to check as it's not boarded... Might have to get this done in order to investigate? 
Roofer tells me that the old fascias there were very rotten and the damp they caused could take months to dry out? 
Also, no soffit vents were fitted, would this be worth doing? I read contradictory things about the effectiveness of this online. 
It's really getting me down, I worry about possible damage to the house that could be very expensive if this goes on.
I am going to contact a damp surveyor after the Christmas period. I just wondered if anyone here ever experienced this issue and could offer some insight? Many thanks in advance. 

FreeBear

Oren said: I have a dehumidifier on all day in the room. When I come home from work I discover the damp has dried out throughout the course of the day. The next morning it's right back again.

That would suggest condensation - Check the insulation in the loft and see if it goes all the way in to the corners of the loft space. If insulation is poor in that area, it will be colder than the rest of the room. Moisture will condense in that area, and a damp wall/ceiling will suck out heat making that area even colder.

If you don't want to run a dehumidifier in there overnight, try one of those passive dehumidifiers or a small electric one (other brands & retailers available).

What temperature are you heating the room to overnight ?

troffasky

If it reappears without rainfall then it could be condensation. Other possibility would be a leaking pipe or tank up there. Are both the walls in that picture external?

If you can't get above that ceiling to check it out from inside, you are flying blind to a certain extent.

If it were me, I would take a couple of small pieces of board up there and move from one board and lift the other one over me, move to that board, etc to get there. I haven't seen the state of your ceiling joists though, so this may be a dangerous thing to do and you will need to judge the risk for yourself.

Assuming it's a normal pitched roof, it's supposed to be "cold", ie ventilated with plenty of fresh air from outside, with insulation above your living area to reduce heat loss in to the loft. If there's not enough air flow up there then soffit vents are worth considering. Lap vents are quicker and easier but may not apply.

Roofer tells me that the old fascias there were very rotten and the damp they caused could take months to dry out?

Does that mean that that old damp timber fascias are still in situ and have just been boarded over with UPVC?

Oren

@Freebear Thank you for your reply. Temperature in the bedroom is usually 19-20c.

@troffasky Thank you for your reply, yes both walls in the picture are external. The old damp timber fascias were totally removed and replaced by UPVC, not just covered over - I took the roofer's comments to mean that any damp caused by the previous bad fascias/soffits/gutters would take a long time to dry out? 

Mutton_Geoff

I reckon that's a leak, not condensation. Can you get into the loft to see that part of the ceiling? If the joists got soaked by a leak now repaired, it could take some time to dry out.

Jeepers_Creepers

I suspect that's an actual leak too - it's far too intense and localised.

Oren, someone needs to get up in to that roofspace for a looksee.

Are 'damp specialists' the best option? I don't know. I'd have thought a good general builder - can you get recommendations locally?

Yes, it can possibly take 'months' for severe damp to fully dry out, but only if the area above was absolutely soaked and holding lots of water - this is very unlikely. In any case, you'd expect from this a gradual lessening of the damp patch, not a coming-and-going of it like you have.

Water is a strange beast - it can find torturous routes to where it ultimately comes through. Although the patch is in the outermost corner of your house at gutter level, the ingress could easily be coming from higher up, including the top ridge of the roof - any chance of a pic of the outside? Is there a chimney stack there?

It's also quite possible that water gaining entry will 'pool' in a particular spot - say on a fold in the roofing membrane - and then suddenly overflow out in slugs which can cause such random appearances of the damp; a leak doesn't have to be even and constant. I suspect the reappearances overnight could be a red herring and not caused by a temperature drop in your room (ie condensation) but actually just due to higher winds and rain showers during the night, or in the late evening.

Basically, I think you have a 'leak' in your roof somewhere! Perhaps a roofer rather than a general builder is the one to ask; 'roofers' will be able to sort out anything to do with roofs (obviously) but also soffits, fascias, guttering, even localised repointing and stuff.

Ask friends/neighbs/work colleagues locally, or use a local Facebook page. Use your judgement if relying on the latter - see how many positive 'secondeds' you get, and how legit they appear. Check each roofer's own page for 'attitude' and feedback.

(And ask the person in the 'loft' if it's nice and cold and draughty up there. Did your old timber soffits have vents in them? Do you have similar neighbouring houses? If so, do they have vents in their soffits? It is very important that the loft space is well ventilated, whilst also having insulation over your ceiling - is there any?)

Mutton_Geoff

And certainly don't call any "damp specialists"

Niv

You really need to get up there and have a look. Not being boarded is not a deal breaker, if you are nimble enough you can just walk on the beams, otherwise you can take a couple of planks up there and bridge them across the beams while making your way to that area.
I think its well worth being familiar with your house and not just rely on a builder/workman going up there and reporting back to you.

Oren

Right, looks like I'm going to have to try and take a look in the loft this weekend! Wish me luck. 

Jeepers_Creepers

Good luck!

Report back please :-)

Do you have a camera - even a half-decent one on your phone? If so, could you take shots of the general loft area (so folk can comment on insulation and how it's fitted) as well as closer-up ones of that corner?

FreeBear

A shot or two from outside might be useful as well - We may pick up on something the roofer/builder missed.