Pointing Composite stone

[mochyndu]

Good Morning all,
I have just hacked off the front of my house because of dampness issues.
Underneath the render I have discoverer that the original finish was Gower conglomerate stone with brick around the door and windows. We have decided to keep it looking this way, but I am having conflicting reports on the best way to finish it.
I am going to have the walls sand blasted to give it a good finish but don't know what is the best option when it comes to pointing. My builder suggest that it will be best to point it with lime mortar as that is what would have been used when the house was built in the early 1800's and then spray it with a water proofer. I thought the idea of the lime mortar would have been to let the house breathe and that spraying it would have trapped in any moisture. Again if I don't spray it am I again going to have problems with damp??
I would be grateful for any advice that's available.
Complements of the season to you all

Roger

 

[noseall]

Will sandblasting not be to aggressive towards the weathering finish of the masonry?

I do believe that thomsons water seal and the like do allow a degree of 'breathability'.

Also, do you need to ask why it was rendered in the first place?

Re-pointing with lime/cement pointing sounds ok.

 

[stuart45]

The cement render could have been trapping the moisture. Lime mortar will help it breathe. I would try it without a sealer first. Siloxane sealers are said to allow some breathing.

 

[cotswoldbuilders]

I agree with the previous 2 answers, but as Stuart said, try it without the sealer.

 

[mochyndu]

Thank you all for your replies. There are not that many stone clad houses left around here so your suggestions are going a long way to help me make my mind up on what to do.
A merry Christmas to you all

 

[RobinClay]

...your suggestions are going a long way to help me make my mind up on what to do.

SO - what did you do ?