Damp patch running length of upstairs bedroom ceiling. Roof issue?

Discussion in 'Roofing and Guttering' started by RichardKn, 2 Dec 2021.

  1. RichardKn

    RichardKn

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    I've recently has a damp patch appear along the length of a bedroom ceiling by the outside wall (following some bad weather - Peterborough area). A roofing company has come out and recommended the following, but I'm not sure it's right & would appreciate people opinions.

    They've recommended:
    1.) To strip ridge tiles, remove old pointing. To re-bed ridge tiles replacing any damaged ones.
    2.) To strip out both verges to the gable and re-bed using premixed roofing mortar.

    As the patch is along the entire length of the ceiling, it seems unlikely to me that the ridge is causing the problem. For that to be the case surely I'd need to have water running down all the rafters roughly equally in order to cause the patch shown in the photo? That doesn't seem likely - no apparent leak to leaking like a sieve overnight? The verge could do with some attention I guess, however, in itself it can't cause this problem surely? The house was build in 1984.

    I feel as though without actually going on the roof the contractor has just picked out the two areas which in his opinion are the most common causes of roof leaks (the tiles all appear fine).

    The thing is, if it's not the ridge or the verges, what could it be? The guttering?

    I'm really stumped on this - I don't want to pay out for unnecessary work, however, what else could be causing the water ingress in your opinion?

    image010.jpg image008.jpg image009.jpg image011.jpg

    Thanks for any ideas you may have.
     
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  3. noseall

    noseall

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    Has someone fixed membrane to the underside of the rafters?
     
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  4. Mr Chibs

    Mr Chibs

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    Is there a lot of insulation (in loft) pushed right up to the eaves (where roof meets loft floor) if so roll the insulation back a bit.
     
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  5. Alastairreid

    Alastairreid

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    Get another roofer, looks like a condensation issue.
     
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  6. RichardKn

    RichardKn

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    Not sure - would have to take a look....although gut feel no. What's your thinking - that water could be travelling down from the ridge, trapped behind a membrane and then spreading out along roof edge at the eve?
     
  7. RichardKn

    RichardKn

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    The loft was re-insulated 12 months ago so possible. Even if that's the case though, how could it be getting wet. Does the ridge seem a reasonable source to you?
     
  8. Alastairreid

    Alastairreid

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    Go in the loft and see if the insulation is damp.
     
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  9. RichardKn

    RichardKn

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    It was immediately following the really bad weather 7 / 10 days ago so it seems likely it's tied to that rather than condensation. Why do you think condensation?
     
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  11. RichardKn

    RichardKn

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    That's a good plan. If it is wet, I assume it's a leak somewhere rather than condensation in the loft though?
     
  12. Alastairreid

    Alastairreid

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    Because that is typical condensation staining.
    It's not the ridge or verge...could be an eave tray issue but unlikely.
     
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  13. Alastairreid

    Alastairreid

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    Take a pic of your loft at ridge and eaves.
     
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  14. JohnD

    JohnD

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    if there was a lot of condensation in the loft, it could run down the underfelt and possibly cause the pattern you see

    is this on the non-sunny side of the roof?

    the water causing the condensation often comes from a steamy bathroom below, but it could result from a rainwater leak or even a water tank.

    have a look at your felt, and look for signs of water trails on the timbers.

    Look and see if the insulation has been (incorrectly) pushed into the eaves, or if there is a gap permitting ventilation.
     
  15. datarebal

    datarebal

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    Rub your hand on the back of the underlay (felt)
    I think condensation too.

    The verge is poor but not the cause of the wet
     
  16. RichardKn

    RichardKn

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    I didn't know you could even get condensation in a loft space! If it was that, how would I go about fixing it? Air brick?
    Many thanks
     
  17. Mr Chibs

    Mr Chibs

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    Air vents, ventilated ridge are two examples.

    is the roof Membrane, black bitumen or more modern fabric type?

    The bitumen type is not breatheable and will trap moisture.

    Also, try to open window after shower, use extractor when cooking, don’t dry washing on rads, and open window a little a night. All these items will create moisture, which can turn to condensation in the loft.
     
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