Four different diagnoses for our mouldy ceiling patch! WWYD?!

[ronconcoke]

We have a black mould patch just to the left of our bedroom window on the ceiling that's grown over the winter. The gutter outside is a bit buckled and worn and torrents of rainwater come out from it when it rains heavily. We finally got a local roofer/guttering person to come and get to the root of the problem and give us a quote. He said we needed a new gutter and new roof ridge tiles at the top of the roof as they're letting water in, which is leaking into the bedroom ceiling.

We got someone else in shortly afterwards - they said it was a roof problem and we needed something doing to the inside of the roof (new eave support system and roof felt). Third guy (personally recommended by a friend whose roof he replaced) said no problem with the roof; it's a ventilation issue in the faschias/soffits. Fourth and final guy came today and said it's a moss problem and wants to charge us £1200 (+VAT) to remove the moss from half the roof and gutter. None of them came to the same diagnosis. Help! Who do we believe/go with?! We can't afford to spend thousands, but we need to stop the problem, whatever it is. The cheapest quote was the first guy who said we needed new roof ridge tiles - the most expensive was the last guy for removing moss. The middle 2 were about the same (roughly £1100 incl VAT). Apart from the personal recommendation, I found 2 online and the last one through a flyer they posted through the letterbox as he was doing some work locally.

We're in the south east, it that makes any difference. WWYD?!

If you have water cascading down the wall I'd address that first.
The other things may also be an issue.

I’m in the process of buying a house which has some mould and damp, the survey highlighted it was suspected penetrative damp. Anyways long story short, I called different roofers (also survey highlighted mould in the loft) and everyone quoted me so much and said I needed a full roof replacement. I actually ended up speaking with a damp & timber specialist from Neil Marsden and the guy who came to the property did a full inspection of everything. He was brilliant and worth every penny, has nothing to “sell” so completely unbiased. I would maybe look into a damp specialist (but an independent one that isn’t trying to sell a product) for an honest opinion.

If it helps, the black mould in the bedroom I’m buying is on the ceiling on the sloped part above the window. He said it was due to roof insulation not reaching as far out into that area of the slope, combined with poor ventilation in the property so the water in the air will stick to the coldest part of the room which is that sloped area. The current vendor dries his wet washing in the room too. So he basically advised to clean the mould with white vinegar (not bleach), dry out the bedroom, increase ventilation in the room, paint etc and that should keep it away but it’ll always be prone to mould unless I get into that narrow/impossible space to insulate it better.

Get the guttering guy to quote for adding vents to the soffits.
If you go into the loft on a breezy day, you should be able to feel the air movement quite noticeably.
With regards to the ridge tiles, check on a rainy day what’s happening in the loft.
Internal felt won’t do anything. Just a bodge job.
As per PP, how is your loft insulation?

I'd get the gutters fixed and ventilated soffits first. (As sounds like they need doing anyway so it won't money 'wasted')

If that didn't solve it I'd move onto the roof ridge

If budgets really really tight you could get a decent dehumidifier which might help the mould but obviously won't solve the actual issue

Source: moved into a crumbly damp fixer upper three months ago. Had lovely new gutters fascias and soffits in Jan which have already made a difference. Dehumidifier is also excellent

Do you heat enough, dry wet washing around the house, shut the bathroom door when showering and after......
We live a 1960s house. If we don't air bedrooms, hest enough and have wet washing around we get mould near windows.
Do you get condensation on the windows?
Condensation can cause mould.

Fix the gutter first—it’s the most obvious issue and might solve the problem without major roof work.

Where does the water from the gutter go when it overflows? Ours hit the patio and then the house wall, that's where we had a damp patch. As for moss, ours is fairly mossy, the corvids come and look for insects under it then toss it to the ground!
1st quote should be able to 'show' via photos the damaged tiles? Ask the others in turn about the different diagnoses and their own and ask how they arrived at them?