ᐅ Remove rough scratch coat plaster for external thermal insulation composite system (ETICS)

We have a house from the 1970s. The masonry is made of pumice stone. The exterior render is firmly attached to the wall. It is a VERY coarse roughcast render, applied very irregularly with many thick areas (sometimes several centimeters (inches) thick).

We need a relatively smooth base for our external wall insulation system (EWI). Now my question is, how can we smooth out or completely remove this awful render? What options are there for dealing with such a render?

Attached are some pictures, thank you for your suggestions.

LarsKoch schrieb:

We need a relatively smooth base for our external thermal insulation composite system.

Which system and what are the manufacturer’s specifications? What does the contractor say?

LarsKoch schrieb:

Now to my question: how can we smooth out or completely remove this terrible render? What options are there for dealing with such a render?

- Sandblasting or bead blasting (but this can damage the pumice once the render is removed)
- Mechanical removal (using a hammer and chisel or suitable tools)
- Applying a smoothing render coat

Do you plan to do this yourself, or should a professional company handle the preparations?

Hello Larskoch,
we have the same issue: Our house from the 1970s has concrete masonry and a solid exterior render. It is a very rough trowel-on render. We also want to carry out an energy retrofit. How have you progressed with this?
It would be great if you could give us a brief update.
Best regards

Bieru Abate schrieb:

It would be great if you could give some brief feedback.

Do you seriously think that someone who has only written one post but didn’t respond to a reaction to their question will reply?

Bieru Abate schrieb:

Our house from the 1970s has concrete masonry and a solid exterior render. It is a very rough trowel-applied render.

Show some pictures.
And the question for you as well: What kind of ETICS with which system? What does the company say about required preparatory work?