Please Help… My House is Leaking!

StupidSmith99

Hello,
Please can someone offer me advice on my leaky house?
It is a Victorian terrace house in an ‘L’ shape. The extension bit at the back is mainly single skim and water runs down the walls when it rains.
I’ve lived here for over 5 years and the roof tiles look quite new, although they are made from a flexible material and are not rigid.
The kitchen ceiling has paint bubbles and water stains on it. It is always mouldy, cold and smells musty.
I’ve had a couple of roofers out, who thought the problem might be related to inadequate flashing and water ingress through a disused chimney stack.
I had an external wall re-rendered as it was blown and the chimney capped to below the roof apex. Also, new lead flashing was applied. The work was carried out in January this year.
The problem has got worse since then and I dread when it starts to rain. The moisture can be felt in the air and it affects food stored in the cupboards.
The underside of the roofing felt seems fairly dry when I go up into the loft, but some of the roof rafters are damp in places.
The guttering is plastic and very basic-looking, but it doesn’t seem to be blocked. The fascia’s are a bit worn, but not overly so.
Please can you lovely people give me advice on what the problem could be? Do you think I need the whole roof replaced? I just want the problem solved and would rather bite-the-bullet, than to just do lots of smaller jobs that don’t solve the problem.
If you’ve got this far, thank you for reading!

Vitor

Based on what you've described, I’d strongly recommend getting a full damp and building fabric survey done by a chartered surveyor (RICS-registered), not just another roofer. For £300 to £600 a surveyor can identify whether the roof actually needs replacing, or if the issue lies elsewhere like water tracking through poor flashing

stuart45

You need to put some external photos on as well.

grumpy_codger

StupidSmith99 said:

...The extension bit at the back is mainly single skim and water runs down the walls when it rains.
I’ve lived here for over 5 years and the roof tiles look quite new, although they are made from a flexible material and are not rigid....

If the water runs down the external walls, not internal, the problem is obviously with the guttering in the first place, not the roof.

Cherryfudge

Be sure the gutter between the two rooves (the middle of the 'L' shape that slopes down) gets checked. I've known that wear through and the water then flowed along, exiting through a ceiling elsewhere. Once it was relined, the problem disappeared.

twopenny

Can you draw the a simple floorplan of your house and indicate where the water is coming I?

The roofing felt on my place exits beyond the tiles and into the guttering preventing water getting behind the gutter.
It's got very brittle and I've left it alone because it's still working. 

I can vouch that our corner gutters that elbow inwards do overflow on all our bungalows.

Kiran

stuart45 said:

You need to put some external photos on as well.

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How shallow pitch is the roof to the extension? If it's too shallow for the roof covering then it will allow rain to drive in etc.

External photos would help eliminate, or provide further, potential issues