Take off old render or leave on? & Thin coat versus scraped?

[RDP27]

We need to re-render the front of our house. I've no knowledge of rendering but estimate that the existing has been on 15/20 years+ and what appears to be a painted layer is coming away (I don't know what condition the render behind the painted layer is in). Could I ask for advice re:
(1) Should the existing render be taken off, or should the new render be applied on top of existing?
(2) Quotes received for K-rend silicone scraped texture and silicone thin coat are similar in price. What is the better product? Two people have said silicone thin coat is the better product (less maintenance, more flexible so reduces risk of cracks and better for exposed areas/bad weather - live Gtr Manchester!). The other said that scraped texture is better as he thinks thin coat can often be patchy on application).
Thank you in advance.

 

[Stewie03]

Taking it off back to brick is always the best way, but that being said if the existing render is rock solid and not delaminated then yes you can render over it, so it's abit of a toss up, but none the less loads of rendering has been done over existing and has stayed on for years

 

[essexandy]

Why are you wanting to re-render at all if your current render is sound?

 

[Tramp]

The new render you have applied will only be as good as the paint behind it

 

[Nottsb]

If you want to play it safe take it back to brick, cut lines into it with an angle grinder and go at it with an SDS and wide chisel bit. Does it sound hollow when you tap it?

 

[tapit]

If you want to play it safe take it back to brick, cut lines into it with an angle grinder and go at it with an SDS and wide chisel bit. Does it sound hollow when you tap it?

What you mean tapit?

 

[RDP27]

Why are you wanting to re-render at all if your current render is sound?

The top painted type coat is all cracked and coming away from what is behind it.

 

[RDP27]

If you want to play it safe take it back to brick, cut lines into it with an angle grinder and go at it with an SDS and wide chisel bit. Does it sound hollow when you tap it?

Thanks for the comments - some parts do sound hollow (bit like when internal plaster has blown). Other parts sound solid.