In article ,
"ben" writes:
wrote:
Our house is a 1930s north London semi with brick on the bottom half
and pebble dash on the top half. The pebble dash is unpainted, and
rather patchy - there are some areas which have previously had
dripping from gutters (now fixed). There are a few small cracks in
the existing render.

We would like to do something to improve the appearance of the house.

1. Would painting the existing pebbledash hide the uneavenness of the
existing pebble dash?

It's a horrible task to paint it, and that's an ongoing
maintenance nightmare -- it would be a negative point for
me if I was looking to buy your house.

Have you thought of trying washing it to start with, which
would not prevent you trying any other route afterwards if
you still don't like it?

2. We are considering re-rendering over the existing pebble dash,

Sounds like a bad idea to me, although I don't know the
products you mention. Might end up trapping damp behind,
and later frost damage could push the whole lot off, or
end up with damp coming through if it's a solid wall.

either with one of the polymer based things like K-Rend or Pliolite,
or with a cement based render. My main concern with this option is
the adherance of the new render to the existing substrate. Is a cement
based render more likely to stick on properly that the polymer stuff?

Any advice appreciated!

I hate it 'full stop' when someone has pebble dashed over they're house but
to render it would make it look flat and featureless. to me pebble dash is
no more than a sponge for absorbing water(rain).

Pebble dash is actually a weather protection layer if properly
done. If it's still on a 1930's house (OP didn't say it was coming
off), then it sounds like it was properly done.

--
Andrew Gabriel