I have a pantry on my house, its attached to the kitchen but has its own slated roof and an outside wall. I have has issues with it getting damp, I have replaced the outside door as that was leaky, re-pointed the wall as it was in poor condition, now I want to check the roof.

There are patches of moss and other bits of weeds, I can't imagine they are supposed to be there, but I'm not sure what to do to get rid of them. How do I check for issues with the roof, and can I do anything about it myself if I find issues, or should I get someone in?

  • 1
    If you have thick moss and plants growing on the roof, I think it's safe to say you have issues with the roof.
    – DA01
    Jul 4, 2013 at 15:16
  • @da01 the moss is quite think, and there are a couple of plants. What's the best course of actions?
    – beakersoft
    Jul 5, 2013 at 14:06
  • Lichen growing on a roof is harmless. A very thin layer of algae is harmless. Anything else growing on the roof is either a problem now or will become a problem.
    – keshlam
    Jun 18, 2014 at 4:40

2 Answers 2


It's probably time to replace the pantry roof. But first, you need to understand how so much water got there that plants started growing on it! Is the pantry roof a much lower slope than the house roof it's attached to? How's the flashing between the house roof and the pantry roof? Are you in a rainy climate? Could the slate roof be leaking water onto wood framing or decking beneath the slate? What are the plants consuming for nutrients? Most things don't grow with only water... are they rooting in some wood?

  • Shade + moisture = moss. Doesn't take much for moss to live on, it gets a good toehold on composition or rock without much dust available. Copper Sulphate granules can knock it down. Feb 18, 2014 at 2:45

You can check "slate roof central" where traditional slate roofers hang out for a referral.

A good option is during the a dry season, pressure washing along with mechanical removal. Always be gentle on slate, and work going down with the lap of the shingles, not forcing anything up. You can get a dozen years of growth off in a few minutes, which may be enough. Be gentle and remove enough material you can see any flaws in slates.

Don't mess with chemical roof cleaners at first: you might not need them.

Beware of roofers that don't understand slate: they're likely to tell you you need a shiny new asphalt roof: a roof that won't last half as long as your old slate.

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