Filling in cracks in render

Habbakuk

I'm going to fill in some cracks in the esternal render to the house with some kind of caulk suitable for outside use. I'm a bit conterned that once I've painted over the render and these newly filled in cracks that the filled 'trails' will still seem obvious underneath the paint. The render is quite grainy even with the paint layers it's got on already. The caulk will I fear be much smoother to the feel and to look at. Any thoughts on how to deal with this to ensure a seamless finnish to my outside house wall? Thanks.

Doozergirl

You need to hack back the cracks into larger valleys and then refill them with render. To ensure a perfect finish, you'd have to skim over the entire house, but they can blend as best they can, then some clever prep before decorating.

If you only put filler in, the cracks will open again pretty quickly with the weather anyway.

Habbakuk

The filler is meant to be permanently flexible......so would they open up?