External render prep

[azzza82]

Hi do any spreaders know if I need to rake out old mortar prior to scratch coat of external wall so the render sits in joints what thickness for each layer and what depth do I rake out old mortar if I need to thanx.

 

[Elite exteriors]

Hi do any spreaders know if I need to rake out old mortar prior to scratch coat of external wall so the render sits in joints what thickness for each layer and what depth do I rake out old mortar if I need to thanx.

Just base it up 3mm

 

[bobski]

Pop one in a grinder.
Overkill really, but sometimes they spec it. Only really ask 6mm or 7mm deep.

mortar blade - Google Search

 

[Smooth criminal]

Well i certainly wouldnt be doing that