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Wet shed!

Andymarra's Avatar

Join Date: Jan 2018
Posts: 1

01-26-18, 12:53 AM   #1 (permalink)  
Wet shed!

Hi all,

I'm hoping someone might be able to help me out with some issues I'm having with a new shed I built.

It's only been up for approx 2 months, but the inside is already feeling slightly wet and the roof is even wetter.

I didn't install a base to build the shed on as it was going on concrete slabs on our patio, so assumed that this would be sufficient. Could this be where water is getting in? I've noticed mould appearing recently as well which is another issue.

Is there anything that I can do to mouldproof the shed without having to install a base?

The roof felt I used was standard that came with the shed, would it be better to replace it with better quality?

Many thanks for any help or advice you can give, I don't want a new shed wasted so soon!


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Bud9051's Avatar

Join Date: Oct 2008
Posts: 9,698

01-26-18, 03:38 AM   #2 (permalink)  
Hi Andy and welcome to the forum.
I assume the shed is currently sitting in that slab. Issues can be moisture following that slab surface right into the shed or even moisture coming up from the ground below. Not sure what the shed is being used for but ventilation is probably what you need. Without a way to get rid of the moisture it will accumulate until sufficient to grow strange stuff.

Are you bringing in any moisture with your use, like dirt or plants?


Tony P.'s Avatar

Join Date: Jan 2015
Posts: 402

01-26-18, 03:42 AM   #3 (permalink)  
It would be helpful if you added some information on materials and a photo to give an indication of style. Also, where it's located and where you live. It's possible moisture is getting in via the concrete slab, particularly if the concrete was recently poured and is still drying.

I suspect, however the issue is insufficient ventilation.

Pilot Dane's Avatar
Group Moderator

Join Date: Mar 2003
Posts: 16,319

01-26-18, 05:47 AM   #4 (permalink)  
Where are you located? What do you mean by "feeling slightly wet". Where is the moisture? Does it just feel damp or is there visible water? Do you have puddles of water on the floor?

Weather can have a big affect on what happens inside your shed. Since it's not heated and air conditioned like your home it's very suseptible to the weather.

joecaption's Avatar

Join Date: Jan 2011
Posts: 3,885

01-26-18, 06:06 AM   #5 (permalink)  
I agree 100% with the possible venting issues.
How close is that slab to grade?
If you built this on top of the slab and the slab extends out beyond the base of the walls and you did not build a stem wall of block first, water can also be getting in under the walls.
The walls should have been at least 6" above the slab or there's also going to be issues with the walls at some point from splash back.

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