Condensation/damp

[mijabobl]

Hi there,

I have lifted floor boards in 1930s house and since the cold has come there is moisture on the floor joists in particular either side of the air brick

The moisture is just on the underside of the joist and only about 3 inches coverage from the air brick

The air bricks are in line with joists, is this bad? Shall I put telescopic sleeve in?

Is this moisture a problem? Or will it just sit on the bottom and fall away?

Any thoughts are welcome

 

[Blagard]

The air brick and joist relationship sound absolutely fine. However I am surprised you find any moisture on the joist as I would think condensation is unlikely. Are you in an extreme exposed location?

You need to look carefully for any other sources such as ground water near the joist ends. Is the airbrick literally at ground level where water can run through it?

Are you sure the joists are damp and not simply stained which can happen during construction.

Contact with water is not a good thing so something does need to be done if wet.

If water is coming through the air brick then running along to the joist a sleeve might divert it to drip into the sub-floor space.

If serious you should look to stop the water altogether.

 

[mijabobl]

Th cavity is bone dry, soil is dampish, but just beads of water by air brick forming, no where else, land outside is a little higher than damp course but it has been dug out and drained, just strange that the beads are only forming by every air brick in the room

 

[Blagard]

Probably just the warmer air in the house condensing at the cold spot then.

Once the floor is back down and floor finishes down the internal warm air will not be circulating near the air brick, so don't worry.

 

[mijabobl]

Thank you