Building sand or sharp sand for exposed render?

[macadonald]

Hi guys,

About to render the outside if the chimney stack... Sharp sand, building sand or plastering sand?

Also just curios, but I've relaid the pots and done some base repair using sharp sand. This is quite a grey mix when dry. I wouldn't want the outside of the stack to look like this. Is it the colour in building sand that gives the yellower finish on most other rendering?

Ta

 

[stevethespreader]

Plastering sand is graded shapsand without the stones I would use plastering sand if u have a grey finish you may have used to much cement