Render over roughcast/pebbledash or knock it off?

[paddypower]

I would like a smooth/napped rendered finish to my external walls. At present these are roughcast/pebble-dashed and masonary painted. Coating is sound and stable. Does the roughcast need removing before rendering or can it be rendered over? It is very roughcast with 1/2 to 3/4" stones. Could be a problem to cover this with scratch coats.
regards

 

[Micilin]

I would like a smooth/napped rendered finish to my external walls. At present these are roughcast/pebble-dashed and masonary painted. Coating is sound and stable. Does the roughcast need removing before rendering or can it be rendered over? It is very roughcast with 1/2 to 3/4" stones. Could be a problem to cover this with scratch coats.
regards

Where is decopierre when you need him?

The ideal would be to spray the render on,as you can get a good thick coat on , without the hassle of your trowel bumping over the stones -but failing that if the existing is sound you can scratch it out.

It will be a bit of a pain but use a stiffish mix. You could scud/dash it on and then flatten it as it picks up a bit. You'll need a few coats. Often , a big stone lends itself to a more uneven wall , as it exaggerates any bumps, so this might just make it it bit more to overcome.

 

[paddypower]

Thanks Micilin
I'll give it a go on the smallest wall and see how it looks, I can always knock it off if it doesn't look too good. I needed to to know it wasn't going to crack, box on the roughcast.

 

[Micilin]

Thanks Micilin
I'll give it a go on the smallest wall and see how it looks, I can always knock it off if it doesn't look too good. I needed to to know it wasn't going to crack, box on the roughcast.

Tá fáilte romhat!

If your first coat is heavy, you might have a bit of cracking in that - but you will only bringing out the first coat to the level of tthe stones.

You won't be going over it again for a few days, so any minor cracking, iif it does occur, won't matter, and you will be able to check if these areas are sound before the next coat. After that you will be giving it tighter coats, so there shold be no problems

Also, I suppose in theory the stones of the dashing will behvae like aggregate in the render and hlep to bind it, Any thoughts on that anyone?

 

[corrie]

Hey Paddy . I`ve mentioned that Roughcast in Ireland on the forum before........It`s like a bunch of grapes? .

If I`m picking you up and walls are painted then I would take it off back down to brick..........unless you can get the paint off with powerwasher. I never go over painted walls with anything.....other than the same kind of paint.

Alex