Waterproof mortar DPC?

[berty3000]

Is there any downside to putting water proofing stuff in the mortar for the DPC course during repointing?

Would there be any harm in using it on all the courses below DPC?

Any recommendations for products?

 

[^woody^]

There are certainly no upsides.

 

[berty3000]

There are certainly no upsides.

You don't rate? What's wrong with it?

 

[^woody^]

It's just pointless for pointing.

 

[noseall]

Is there any downside to putting water proofing stuff in the mortar for the DPC course during repointing?

Would there be any harm in using it on all the courses below DPC?

Any recommendations for products?

It may affect workability, which would be disastrous for a repointing job.

 

[berty3000]

Thanks both.

My main thinking is that if any of the DPC gets broken off whilst chiselling out the knackered old mortar, this waterproofing stuff might offer some backup and comfort.

I'm planning to have the wall above the DPC rendered so don't want any wet bricks behind it. i.e. I don't want moisture rising up above the DPC coarse and then being trapped behind silicone render.

Any ideas?

 

[^woody^]

You are over-worrying

 

[berty3000]

You are over-worrying

Haha, that's probably true.

But how will moisture that rises up through capillary action past a broken part of the DPC escape of it is behind render!?!?

 

[^woody^]

The force required to push moisture up through a few mm of mortar is less than the force of gravity pushing it down and the rate of evaporation taking it away and a few other sciency related laws.