Plastering over pebbledash?

[patriciastar]

I am keen to get rid of the pebbledash on my 1930s semi. A building company has suggested that they can leave the pebbledash as is and render over it - but this sounds very questionable to me? The pebbledash is in very poor condition. Just want a sense check here as my building knowledge is limited. Is rendering over pebbledash as problematic as my instincts suggest?

Polite refusal...
If the pebbledash is blown then whatever goes on top is going to fall off. You can clad over it using battens but plastering on top is just not a good idea.

Bump

Google everywhere suggest that's a very bad idea, extra weight on top of old pebble dash won't stay

There may be sealants out there that might work

Your instincts are correct.
Just politely getting the terminology correct, you render over pebbledash, not plaster.
It's possible, however as Loofah said, pointless unless it's in perfect nick. At a minimum you'd have to scrape/chip/hammer all over the existing pebble dash to dislodge anything loose. Then wash/pressure wash to remove the old dirt etc and give the render something to grip.
You could hack off the old PD if it's not in great condition, usually the innermost scratchcoat is ok. Then render over that. With a couple of modern electric hammers with wide blades, could be surprisingly easy. You'd have to protect the lower window sills etc from falling PD.
You need a full scaffold as well.

Just replaced some pebbledash with render. They took off the pebbledash first. It didn't take them lying to get it off.