Tanking a basement

[mcg_]

C Lee Farquar said:

The reason why they say a painted finish isn't recommended is condensation. Water runs off the walls, leaving you thinking the tanking has failed. Think bathroom window after a shower.

Ideally you want to render before and after the slurry. If you tank directly to the walls you run the risk of salts and other nasties in the mortar joints blowing your tanking barrier. If you cock it up it's a big job to strip off.

Ah interesting.

For the purpose of storing stuff, would a tanked room (no render or anything, just the slurry applied to brick) be much better than an un tanked room? Things left down there are the moment go moldy at the moment, unless they're well off the floor and away from one particularly damp wall.

[C Lee Farquar]

mcg_ said:

Ah interesting.

For the purpose of storing stuff, would a tanked room (no render or anything, just the slurry applied to brick) be much better than an un tanked room? Things left down there are the moment go moldy at the moment, unless they're well off the floor and away from one particularly damp wall.

You have essentially three ways of improving the environment.

You can improve the ventilation or seal it up and use a dehumidifier or tank it. I'm assuming you can't lower the outside ground levels.

We had improvement in the past by lifting dirt/flag floors and laying a concrete slab with membrane. A bit of through ventilation can give significant improvement. As you've suggested using a scabbler to get back to the original masonry helps.

I'm making assumptions as I haven't seen your cellar but hopefully will give you some food for thought. The good thing is that if you try the above you can still tank if it isn't dry enough for you, and the work you've done will still be of benefit.

From what you've said I think cementitious tanking is the last resort.