Damp in shed

davek0974 · Post by **davek0974** » Tue May 30, 2023 6:49 am

Hi all,

I have a 8x6 wooden shed, only built a couple of years back. I made the cardinal error of using up some spare kingspan insulation and lined the roof with ply.

Yep, you guessed it i now have mould. I have pulled the lining down and removed the insulation, left the window open for a few days in the warm weather and things are drying out now but i have a very thin layer of light green mould on some areas of the underside of the marine ply roof sheet.

The issue was made worse by the spill-vent on the single UPVC window being left shut as well.

Is there anything i should do with this or just brush/vacuum it off and leave it as-is??

There does not appear to be any lasting damage to the structure.

Thanks

dewaltdisney · Post by **dewaltdisney** » Tue May 30, 2023 7:17 am

I would use a bleach solution. Paint it on liberally and leave it to dry out, by the morning it will have killed the mold and you can brush it off. Obviously, use eye and mask protection.

DWD

davek0974 · Post by **davek0974** » Tue May 30, 2023 7:48 am

Sounds good, just a normal bleach cleansing mix?

dewaltdisney · Post by **dewaltdisney** » Tue May 30, 2023 8:28 am

Yes,household bleach mixed in water, not too diluted. I painted some gates that were green, and by morning and a jet wash down they were clean. I also had a green shed wall and that was cleared overnight after painting with the solution.

DWD

davek0974 · Post by **davek0974** » Sun Jun 04, 2023 4:01 pm

The bleach seems to have neutralised any mould, smells a lot better now.

However the shed is still not right, i'm guessing it needs air flow. There is a vent strip at the top of a single UPVC window and that is full open now, but the humidity in there is still way too high, not sure why?

Its measuring about 42% indoors at present but the shed is showing 75% and feels very humid. I'm guessing this is bad.

The shed is joined on to a double concrete garage which has been lined and decorated and now houses a pool table. There are no opening vents in this part at all. I was weary of adding vents as in the winter it is kept at a min 7c with background heat to stop the table getting too cold etc.

Any ideas here - i'm looking to stop any damage occurring to the tools in the shed or the decoration/table in the garage part, picture of pool area below.

: Pool room.jpg (99.12 KiB) Viewed 1419 times

aeromech3 · Post by **aeromech3** » Tue Jun 06, 2023 3:21 am

I find my wooden shed, open space on all sides, feels humid, and 75% is a hi moderate level, I am guessing the wood holds some moisture and a flat roof will have a large temperature range during sunny days, your venting should improve matters but check for staining on the roof wood indicating leaks.

davek0974 · Post by **davek0974** » Tue Jun 06, 2023 5:33 am

Thanks, the roof is good, it has an EPDM sheet glued on and appears to be in mint condition, there is no staining on the inside or sign of any water ingress.

My guess is to add some through ventilation, maybe even forced by a small fan ?

I'm just not sure whats best. Today the house is reading 45% and the shed/pool room is reading 70% still