I've just moved house last week and today have noticed a drip in my dining room. What's odd is that it isn't raining - in fact, today is the first warm day of the year.

The "water" is a brown colour, but doesn't seem to have an odor. Moreover, I'm also noticing drips from the roof line on the outside of this part of the house.

It's a single story extension without plumbing, so I don't think it's a leaky pipe. The gutters are bone dry and there's no standing water on the (flat, leaded) roof.

What could be causing this? And how would I solve it?

  • Do you have any AC ducts running in the area and have you been running the AC unit?
    – JACK
    Mar 30, 2021 at 12:27
  • 1
    Condensation is the usual suspect given no plumbing and no rain. Depending how cold it's been, possibly frozen condensation melting.
    – Ecnerwal
    Mar 30, 2021 at 12:28
  • @JACK Good idea, but no - no AC in this house.
    – Tom Wright
    Mar 30, 2021 at 12:40
  • @Ecnerwal Hello again. Condensation between the lead and the timbers? Could be, I suppose. Not had any frost recently, so probably not ice melting.
    – Tom Wright
    Mar 30, 2021 at 12:41
  • 1
    Sometimes a leak collects in insulation or builds up until it finds a hole to drip through. I rain a few days ago may have collected enough water to finally start dripping.
    – Ed Beal
    Mar 30, 2021 at 13:57

2 Answers 2


We had a bunch of builders take a look and the consensus was that the timbers in the roof structure were "sweating" in the heat. This was apparently caused by a combination of the outer roofing material (lead, in our case) not being 100% water tight, and the void above the ceiling not being adequately vented.

We had the roof replaced, including new beam. The problem hasn't recurred.

  • Good point, I didn't mention the new bleed vents above the line of the ceiling. My gut tells me that the new roof is the main driver here though - preventing water ingress in the first place means less moisture to vent.
    – Tom Wright
    Jan 20, 2023 at 13:59
  • That information would be better presented in your answer. :)
    – isherwood
    Jan 20, 2023 at 14:01

When water leaks through ceiling it makes drywall weak. Recently I replaced leaky hot water pipe in the house. A big area of ceiling was damaged. Not sure how big or a small ceiling portion is affected in your case. I would first make a small hole with a nail or at least 1/4” drill. If water is accumulated and comes out faster or more you may have to cut 12x12” piece of ceiling. (I would start there.)

Let us know what is your finding. Making hole or cutting small portion of ceiling was suggested based on your info.


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