Sand/cement or silicone render. What to do when the pros see it differently

[SJRSJR]

Hello, would appreciate your thoughts.

My house is 1920s with a roughcast render. At some point bay windows were taken out on the front elevation and the render is a patchwork of finishes. I'd like to get the lot re-done so have spoken to a couple of renderers. One said silicone render 'all day long'. the other said sand/cement render 'all day long'.

I do like the idea of not having to paint a silicone render, but when I look at all the new builds I wonder if it's right for an old house, especially as the other elevations will stay sand/cement. Is silicone really invincible or could it bring its own problems and still discolour? It'd be white.

The silicone guy said if I wanted sand/cement render the existing render would have to come off, whereas they can go over the existing render with silicone. The sand/cement guy said that if the existing render is sound they start by putting a fibreglass mesh over the existing render.

Also is knocking off render likely to cause cracks in the plaster inside (it's cavity walls)?

Thanks

 

[Wayners]

Silicone needs washing over every 10 years but is breathable.
Also different colours.
Sand and cement it's tried and tested but does have it's problems.

It's just different options.
You just need to decide what's best for you.

 

[SJRSJR]

Thanks. There is a potential problem area where the bay windows were removed and a timber frame with plywood put in to make the elevation flat. The different expansion rates of the timber vs brick has caused vertical cracking. I’m told that fibreglass mesh will help with that.

I did think silicone would make more sense but apparently its ’flexibility’ isn’t as good as you might think.

Will have to mull it over and look more closely at other houses..