Help! Shed's gone mouldy....

[Rockford]

Hi,

Looking for a wee bit of advice on how I can get more air circulating inside the shed.

It's a newish 7 x 5 pent shed that sits on a slabbed area at the side of the house. The door is on the front (long & heighest side) and there is a single paned non-opening window on the short side that gets the most light. There is only direct sunlight for around half the day at the height of summer and that side of the house is quite shaded. It's used for storing lawnmower and garage overspill, with half given over to my workbench and assorted handtools. The workbench is made (upcycled?!) from four 4x4 fence posts and some 2 x 4 fence rails, with the top being a half sheet of (I think) 18 mm plywood. It is only used for hand carving and pottering and no heavy stuff. There is no finish on the top, although the carcass (made from the fencing) is treated timber.

For a wee while, I have noticed some speckling/mouldy marks on the bench top, which feels a bit damp to the touch, although there is no distortion or other deterioration of the plywood at all. My plan was to wait until it was a bit drier and warmer and to bung some fungicide on the top and and then refinish it or just replace the plywood sheet. However, I was in to get something at the weekend and saw that there was now also a hint of greenish powdery mould on some of the hand carving tools and some of the small WIPs (I've been carving a nativity for almost 5 years and have only finished four pieces!!). The shed itself is not treated on the inside (although inside OSB roof is painted white with some left over emulsion) and there is no obvious mould/damp on any of the shed timbers and no signs of water ingress.

My thoughts were that is a mixture of condensation and poor air circulation. There is some ventilation at the top where the roof overlaps the shed walls, but no vents at ground level. Would a couple of small grille type vents at ground level help? What about a spinning vent in the window? There is no means of getting power to the shed other than trailing an extension cable, so no prospect of heating it over a period of time is not really an option.

I can accept a bit of condensation and as it's basically outside I can accept some cleaning up of tools might be required, but I don't want to kill myself as a result of a mouldly workspace!

ANy suggestions welcome!!

Brian

 

[Racers]

I had the same problem with my shed I got lots of mould on the roof so I drilled a couple of 50mm holes with a hole saw close to the apex on each end and stapled some scotchbrite pad over the holes to keep the bugs out.
It worked a treat.

Pete

 

[Ttrees]

Is french drains all round possible ...
Our garden shed at home has similar problems ...
...Must do drainage this year .
Vents probably would help, but I think this would be ventilation for your body heat,
to stop it condensing on your tools ...
Depending on how much of a good fit your door is ...it might not make much difference ...
It could however provide a necessary draft ...but a shed that size, might not be necessary ...
Have a dig around the perimeter of the slab ...is it damp or wet ?

 

[Rockford]

Hi,

Thanks for the feedback.

The area around the shed drains well. There is a 3 x 2 slab path running around the house and the shed is on part of that has been extended. The shed sits against the edge of the slabbed area and there is a drain/vent about three feet away - we're in a new house on a brownfield site.

It's quite bizarre, there is no evidence of any mould anywhere on the structure of the shed (which was built from scratch by someone who knew what they were doing - door fits well and window is well sealed), no condensation evident on window - the mould is only on the top of the bench, some of the work pieces and the wooden tool handles. I haven't worked in it at all since about the beginning of November, as it's been too cold, so it's definitely not me raising the temperature (and at the speed I work, I don't generate much heat )

I'll try a couple of additional vents and/or 'air' it more often if it ever stops raining....

Thanks for the suggestions.

Brian

 

[worn thumbs]

Can you identify the type of ply on the bench top?If its birch it would be entirely in keeping for it to grow mould spots in short order.My shed isn't particularly well ventilated and I have no trouble with mould on timber,I do have rust occurring on steel in very short order though as I live 150 yards from a river and cold, damp air gathers in the valley.