Condensation on Ceiling of Workshed

I am looking for advice on how to deal with condensation that has just appeared on the ceiling of my workshop. I dug out the workshop under my house in Pymble. (Carried out over 30 cubic metres of dirt in buckets, filling about 12 skips). It is 4 metres wide by 7 metres long and 2.4 metre ceiling height. Floor is poured concrete, walls brick. The floor is about 600mm below ground level. The ceiling/roof is a cement terrace/deck 150mm with tiles on top. Access is via double doors on one short side. The other short end has an opening around 1.2m by 1.2m to access under the the rest of the house.

No doubt the onset of cooler weather is a factor. There was no condensation over summer or the rainy season that was meant to be summer.

Any suggestions would be most appreciated.

Regards

Peter

How's the general ventilation? It sounds like a lot of moisture is coming out of the ground into the workshop air. You might need to put a moisture barrier up on the walls.

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Originally Posted by BobL

How's the general ventilation? It sounds like a lot of moisture is coming out of the ground into the workshop air. You might need to put a moisture barrier up on the walls.

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I concur, mate of mine did same thing, but he ended up with puddles on the floor, due to the fact that he dug lower than the natural ground and also below the brick foundations.

Some tar base paint on the walls and an agi drain on the outside walls to take the moisture away should go a long way to sorting your probs out

Friend of mine did the same thing for a wine cellar. He tar painted the outside of the walls before back filling. Also put in drain around outside. Didn't help totally. He had to tar paint the inside as well. His way into it was a trapdoor in a hall cupboard. He wound up putting in a ventilation fan in the ceiling (floor of cupboard and a louver door) on a timer to vent it all.

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Originally Posted by Acco

I concur, mate of mine did same thing, but he ended up with puddles on the floor, due to the fact that he dug lower than the natural ground and also below the brick foundations.

Some tar base paint on the walls and an agi drain on the outside walls to take the moisture away should go a long way to sorting your probs out

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Many thanks for the replies. The concrete floor has lots of ag drains underneath it with vapour barriers. The walls, where they are below ground level, are either concrete or where brick have been double or triple coated with bitumen paint and ag lines. Ventilation could be better - had 3 vents down one long side which I made into larger glass brick windows for natural light- maybe I need to add some vents back in? I have one large mesh vent in one corner (where the dust extractor will go).

Any other comments would be welcome

Regards

Peter

Air flow. The air needs to be moved to carry away the moisture, been there, done that. In my case I put passive vents into the floor above and the breezes coning through the doors in the basement move the air enough to freshen up the basement from that dank atmosphere that basements get. There are low voltage or solar powered fans you can get but the last time I looked they were exy. Another idea that works is light tubes which have ventilation built into them.

Just a thought: was any PVC moisture barrier placed under the concrete floor and extending up the outside of the walls up to just above ground level?

Too late to do it nowm but it could well have helped, as well as better ventilation.

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Originally Posted by wun4us

Just a thought: was any PVC moisture barrier placed under the concrete floor and extending up the outside of the walls up to just above ground level?

Too late to do it nowm but it could well have helped, as well as better ventilation.

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I did on 3 sides but not the lowest side (existing brick wall) but I did excavate the outside of that wall and apply 3 coats of bitumen paint. Looks like I am down to adding ventilation of some form(s).

Many thanks for the comments

Regards

Peter

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Originally Posted by Mini

Air flow. The air needs to be moved to carry away the moisture, been there, done that. In my case I put passive vents into the floor above and the breezes coning through the doors in the basement move the air enough to freshen up the basement from that dank atmosphere that basements get. There are low voltage or solar powered fans you can get but the last time I looked they were exy. Another idea that works is light tubes which have ventilation built into them.

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I think my solution lies in this somewhere. I put a large floor standing fan from Bunnings down in the workshop and turned it on high for the whole day with the doors open and the moisture is gone.

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Originally Posted by The Hun

I think my solution lies in this somewhere. I put a large floor standing fan from Bunnings down in the workshop and turned it on high for the whole day with the doors open and the moisture is gone.

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Good thinking 99.
I think you've cracked it.
So maybe a small exhaust fan on a timer that goes for 15 mins each hr??