Patching up loose render

dearlouise

I've recently renovated the inside of an outbuilding to purpose it for storage and my cats to live in while I temporarily live with my Mum. There was a massive damp problem in the building, which I've tried to combat. However there is a lot of damage to the exterior render, which can't be helping keep the building damp-free. While we have better weather, I think it's times to fix it.

I've done some research only to be very confused. The garage rendering is fine on 2 walls, then on the more weather exposed, it quite patchy.

What should I be using to patch it up? My original thinking was to pull off any loose rendering, then patch it up with this: http://www.screwfix.com/p/cementone-general-purpose-mortar-5kg/36857 as it does say its suitable for rendering.

However I have read varying recommendations on using waterproofing before or after rendering... I'm a little confused about this. Ideally I'd like to make sure no damp gets back into the building! As there are bits appearing here & there.

uk_messer

The render may be compounding the damp problem by bridging the DPC or pooling water if it's blown away from the brick. Where exactly is the damp - low down or high?