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- 14 Sep 2025
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Hi, last year I got a shed delivered & put together by a local company. My dad helped me put guttering up along the facia board so that it collected rain into a water butt.
Skip forward to last month when I noticed a big patch of black mould on the top of the shed, near the air gap that is built into the design of the shed. (See attached pics)
Then over the weeks and days I have been noticing more and more of my belongings in the shed having mould on them. I've had to throw some kids toys away, my tools are covered in mould, basically anything that is porous is covered in fluffy green mould, even mine and my kids' bike handles & seats.
I go in and out of the shed regularly for tools & bikes and air it out when we get a nice warm/sunny day so I can't understand at all why it is getting SO much moisture inside it!
The company have been quite good in that the boss rang me last week and said he would send his men round to replace the black mould covered boards and felt if needed as it looks like it might be a leak. He also said they would weatherproof the outside again.
However today the guys turned up and almost immediately one of the workmen started blaming the black mould on the positioning of my guttering which is:
brackets fixed to fascia board and gutter sits right under the edge of the roof (which is felted) with an extra little bit of felt underneath that felt.
However, the guys, and the boss have all said that the gutter should be sitting under the timber fascia board, so the rain runs off the roof, down the fascia and into the gutter.
What do you guys think?
I might try and add some drawings to show what I mean if this doesn't get much traction because I'm talking a load of gobbledegook
The last image is the outside of the shed as I am convinced the weatherproofing treatment they used has ran off with the rain (they apparently use Creosolve - any opinions?)
Skip forward to last month when I noticed a big patch of black mould on the top of the shed, near the air gap that is built into the design of the shed. (See attached pics)
Then over the weeks and days I have been noticing more and more of my belongings in the shed having mould on them. I've had to throw some kids toys away, my tools are covered in mould, basically anything that is porous is covered in fluffy green mould, even mine and my kids' bike handles & seats.
I go in and out of the shed regularly for tools & bikes and air it out when we get a nice warm/sunny day so I can't understand at all why it is getting SO much moisture inside it!
The company have been quite good in that the boss rang me last week and said he would send his men round to replace the black mould covered boards and felt if needed as it looks like it might be a leak. He also said they would weatherproof the outside again.
However today the guys turned up and almost immediately one of the workmen started blaming the black mould on the positioning of my guttering which is:
brackets fixed to fascia board and gutter sits right under the edge of the roof (which is felted) with an extra little bit of felt underneath that felt.
However, the guys, and the boss have all said that the gutter should be sitting under the timber fascia board, so the rain runs off the roof, down the fascia and into the gutter.
What do you guys think?
I might try and add some drawings to show what I mean if this doesn't get much traction because I'm talking a load of gobbledegook
The last image is the outside of the shed as I am convinced the weatherproofing treatment they used has ran off with the rain (they apparently use Creosolve - any opinions?)