Efflorecence

[dieselpower]

I built a blockwork skin round a timber frame, probably about a year and half ago, now the guy is ready to finish it now, most of it is getting faced with stone but there are a few elevations to be roughcasted. However the amount of salts that have leached out the blocks and crystallised are unreal ( meant to take a few pics but forgot) the stuff is pretty solid and I'm thinking a bit dodgy to just clean it and scratch straight over, so was gonna clean off and then prime walls probably with an sbr slurry but time consuming.
Is likes of betocontakt or plasprime just as good, need to order it though cos builders merchants out in these stix only have the basics!

Any advice much appreciated..thanks..

 

[Builderboi]

You need an exterior primer..

 

[Denman]

I would be treating that with a mild brick acid to dissolve the salts then hit it with SBR slurry first

 

[Arti]

Anti-Sulphate

 

[superspread]

Spray WHITE vinegar on it

 

[carlos]

Sulfate resistant cement??? Sulfate resistant tanking coat first??

 

[spreadeasy]

Sulfate wash

 

[Dr.B]

This happens to block work if it is exposed to water for a long period. Sometimes it comes out of the block itself or the mortar joints.
On heavy leaching you can try to clean it up a bit with acid wash and give it a tight scratch coat using SR cement and waterproofer.

 

[plasterjfe]

Brick acid it. Chip of the hard bulk with a powerprep or similar. Use a prep coat as mentioned maybe your own mix slurry. Mesh the first pass

 

[dieselpower]

Cheers folks, looks like what you see on inside of caves, jobs a bit of a mare tbh full stop.
Was gonna roughcast it when I built it but now being back last week and saw what I have, I'm glad I never cos the windows are a good 35-40mm smaller than openings I built block round, probably need to pack them out with more than render.. Thanks...