Jon Parker wrote:
I'm building a double-BBQ of the standard size 670mm wide (but two of
them side-by-side) with a little extra bit on the end for a paving
slab to make a table. It's 17 whole bricks per course and 11 or 12
courses high. I have 210 bricks.

Can someone tell me how much cement and sand I need to buy?

It's building sand to get, right? Ratio of 1 cement to 6 sand. I have
a mixer ready to use, plasticiser and brick ties.

Thanks
Jon

6 sand and 2 cement - you'll need some extra to bed the paving slabs etc on
after it's built.

Don't use 6:1 ratio - the heat will destroy such a weak mix in short time,
mix it 3:1