If you have a new account but are having problems posting or verifying your account, please email us on [email protected] for help. Thanks :)
Private profiles - please note that profiles marked as private will soon be public. This will facilitate moderation so mods can view users' warning histories. All of your posts across the site will appear on your profile page (including PI, RI). Groups posts will remain private except to users who have access to the same Groups as you. Thread here
Some important site news, please read here. Thanks!

Plasterboard in an unheated/uninsulated garage

  • 12-12-2021 5:51pm
    Registered Users Posts: 396 ✭✭ Hyperbollix

    I have a block built, single wall garage beside the house. It's plastered on the outside but bare block inside. During the summer I decided to tart it up abit with a few sheets of insulated plasterboard and cover over a concrete block plinth entirely with plywood so I could stack some storage boxes etc....

    I painted the back wall with a cement/waterproofer mixture to seal up the pores of the blocks. A few days later I put up the plasterboard and painted it white. Now that we're in the depths of winter I can see I've made a mistake! The plywood I've put down is damp to the touch and covered in a film of mould, while the plasterboard is destroyed with black mould, especially under a window. Even timber shelving at the other side of the garage is speckled with mildew....

    Am I right in saying that this approach can't be used in an unheated environment? I've no intention of making this garage into a insulated space with a heat source, so what is my best bet when it comes to lining walls, shelving, using plywood etc?


  • Registered Users Posts: 30,666 ✭✭✭✭ listermint

    Is there a moisture source in there? That can even mean is there water coming from roof or through cracked render.

  • Registered Users Posts: 396 ✭✭ Hyperbollix

    Took off one of the plasterboards panels with a lot of mould on the surface and the wall behind is dripping wet. This is bare block painted with a cement/waterproof mixture and previously would have been dry during the winter. Is that condensation due to outside/inside temperatures, trapped behind the panels? Same thing happening with the plywood on the concrete plinth, discoloured green/black and damp to the touch....

  • Registered Users Posts: 6,167 ✭✭✭ Flinty997

    Is their any damp course in the wall.

  • Registered Users Posts: 7,294 ✭✭✭ the_pen_turner

    What kind of block wall

  • Registered Users Posts: 865 ✭✭✭ Pinoy adventure

    Solid or cavity block built wall ?

  • Advertisement
  • Registered Users Posts: 396 ✭✭ Hyperbollix

    Would be 9" cavity block, single row. Plastered outside, bare block inside. I assumed since the walls never showed signs of water penetration before that it would be ok to just put up afew sheets of p.board with foil backing. Obviously not.....