Moisture coming thru concrete floor

[fars]

Hi,
I've got a storeroom which is slowly getting growing mould on lots of stuff. It's got breeze block walls, plus a concrete floor and has zero air circulation.

From reading on the forum I figured the first thing I'll do is put in a ventilation fan to start air moving through the room, plus wipe the existing mould off with diluted bleach.

But I also noticed that the concrete floor in one corner in particular appears quite damp. There is a drain sump below it on the other side of the floor/wall which has water in it. The water level is usually 1.5 -> 2 feet below the concrete floor level.

Is it a worry to see dampness coming thru the concrete? Should it be waterproof, or is this expected for something so close to a drain?

Thanks,
Far

 

[Burnerman]

It will depend if a waterproof membrane was laid down before the concrete.....if there wasn't, moisture will surely wick through!
John

 

[fars]

Ahhh ok.

Thanks !

 

[BobKbta]

Your problem is condensation. You are best leaving it closed in and running a dehumidifier.

 

[fars]

I've left the door to the room open the last day and while it's a securiy risk, the wet patch on the floor has gone.

When is it better to use a dehumidifyer as opposed to a ventilation fan?

 

[freddiemercurystwin]

Your problem is condensation. You are best leaving it closed in and running a dehumidifier.

Awful, awful advice! How can you possibly know for sure it is condensation and why would it occur on the floor and not the walls/ceiling where condensation tends to appear as mold. And if it was condensation the solution is not to run a dehumidifier but ventilate the space!

To the OP just because the damp has disapeared does not automatically mean it was/is condensation, it just means that the damp is evaporating quicker than it is being absorbed by the slab.

 

[fars]

The mould isn't really on the walls or ceiling, it's basically on stuff stored in room that has the capability to rot - cloth, cardboard, paper, even wood.

Nothing outside the room has mould. Outside being an underground garage, which has some ventilation via mesh garage door.

Since nothing outside the room gets mouldy, hopefully if I put some ventilation in to make the conditions similar in the room to outside the room, it should resolve itself.

Now I know water wicks thru concrete I'm not too concerned about it, especially as it disappears when there is air movement. Thanks again