Ventilation to combat damp in store room

[damouse]

Hi all

We have a single walled store room that is adjacent to our downstairs shower room - no DPC . I've noticed that a plasterboard wall in the store which is furthest away from the house is now showing signs of penetration damp and I've been advised that I need some ventilation in the store.

The vent from our shower is currently ducting into the store room but it's not venting out from the store room to the outside however. Hence I think this could be the main cause of the damp - i.e. moist air not escaping in these cold months. So thinking I may need to hire a circular core drill to cut out a 100mm hole for the extraction of the shower vent ...

However for general ventilation in the store, should I use the same core drill and create multiple 100mm holes and cover these with a square/round grill?

Or should I fashion my own air brick by simply drilling holes through the brick work at regular intervals using a bog standard large masonry bit - it's a single walled construction so should be a simple matter?

Finally, where should the air brick/vent be position for maximum effectiveness - high up near the ceiling or down near ground level.

Appreciate any advice here!

 

[Dave54]

Unless I've read this wrong, your biggest problem here is that the shower room is venting into the storage room. It should be ducted to expel the moist air from the shower room directly to the outside.
The damp you have is the moisture from the shower room condensing on the colder walls.
It won't hurt to have a vent in the storage room but it might not be necessary once the shower vent is sorted.

 

[damouse]

Thanks Dave

Yes - you are spot on. The coldest wall is North facing and furthest away from the house ... and this is the one hit with the damp.

I think I'll tackle the bathroom vent ASAP and will also for good measure drill two additional 100mm diameter holes in the North facing wall for air flow.

Any suggestions on if these air flow vents should be positioned high up on the wall or at the bottom - or does it not really matter?

 

[Dave54]

Personally I think I'd deal with the bathroom vent as you say, and then see whether I still had a problem before starting to fit vents.
I'd fit them high up on the wall myself. Let warm, moist, air out. That's what I've done with my garage, and it's seemed to help this Winter.