Mouldy Shed

[Sally27]

Hi,

We recently had a new shed built and after just a few weeks the shed is full of mould and smells like rubber. We insulated it so we could keep it warm as we also have a treadmill inside. we try to leave the window and door open when we can however anything wood and fabric is now full of mould and we have no idea why. Any ideas would be really helpful. Thank you so much.

 

[Deleted member 174758]

Single thickness blockwork, is there any DPM? Might explain why you seem to have water seeping through the wall. Also single skin blockwork with no insulation on the inside won't retain heat so it will chill off pretty fast inside, meaning that any water vapour in the air (from you breathing or sweating) will inevitably condense on the first cold surface (normally metal or impervious materials like PVC), especially as the internal temperature drops. You can mitigate this by extraction, but without insulation I can't see it ever being 100% right. Was this built as a shed, or did you ask for what needs to be, in effect, a habitable building?

 

[flameport]

How long has it been since the concrete slab was poured?

 

[foxhole]

Can’t see any ventilation?

 

[Odds]

An airbrick would've been handy to install during the build. A dehumidifier would help. You can get chemicals to spray over the mould and scrub down affected surfaces but it's persistent stuff.

 

[CBW]

Did the layer of screed dry out and was the building allowed to be dry before using it? Agree with others, can’t see any ventilation.

 

[JohnD]

@Sally27

Water is clearly coming through the wall. Please show us the guttering and downpipe on that side, and for the neighbours adjacent sheds. Please show the edges of the ground slab, and how water and damp soil are prevented from touching it.

Cut holes for airbricks near the ceiling on at least two sides.