airbrick venting cavity only

[dormermike]

Hi

Front bay of my house has airbricks which ventilate the cavity only - the vent does not come inside the house. On the inner skin there are "damp" patches at the base of the wall where the concrete floor meets the brick work - suspiciously near the vents.

Is it worth blocking up the external vents? there is quite a gale coming through them. The front bays are also not insulated to I guess this compounds the problem...

Any advice offered appreciated.

Thanks

 

[stuart45]

Cavity vents have been known to cause cold spots on the internal walls and are not used now.

 

[dormermike]

Cavity vents have been known to cause cold spots on the internal walls and are not used now.

Thanks - thats kind of what i'm thinking.. as its a really localised spot of "damp" thats occuring at really odd intervals.. left house for a weekend, torrential rain all weekend, got back and floor dry as a bone. Hot dry week, floor looks damp. Wet weekend, floor gets wet. Its odd, there is v little pattern to it other than the floor/wall junction can be as low as 8-10c when the room is 18-20c.

Cheers

 

[stuart45]

When you were away you were not producing the moisture that you would be when at home. If you check the R/H and Temp of the room, any surface below the dew point will attract condensation.
For example when your room temp is 20C and the R/H is 60% the dew point is 12C.