Quote:
Originally Posted by bpu699
power washing accomplishes 3 things...
1) Cleans the old mortar dust off the stone. If the stone isn't clean, the new mortar doesn't stick
2) Wets the stone, which helps form a stronger bond. You can mist the stone also, accomplished the same thing. If the stone isn't moist you may get a dry set, where the mortar dries, but doesn't stick...
3) Gets the weak mortar out better.
You could do the same with a hose...
Yep, its messy  |
I get it but I'd never attack an old stone house with a power washer rather than the gentler approach with a brush
With a house that is that old you may find below an outer mortar layer the stone is held together with mud and horse hair and the internal wall cavity is just loose rubble