Bricky mortar mix.

I'm about to start a garage using a 'bricky', and their website suggests a mortar mix including lime. Not many mortar mixes seem to include lime (as far as I can see). Is it really necessary, and what does it achieve? They don't explain why on the website.

"Mortar Mix - 6 part building sand, 1 part cement & 1 part hydrated lime, add water with plasticiser or PVA adhesive mixed 5:1 in the water. (Never use washing up liquid)"

From - http://www.bricky.com/how-it-works.html#tips

Cheers for any replies

I think its a bit redundant. To my understanding (only built two walls) lyme adds pliability and helps deter moisture. But plasticiser does that, doesn't it?

as above, you don't need lime if adding a plasticiser.

Excellent. Cheers. I'll not bother with the lime them. It seems to be that it's either a plasticiser or for brickwork that's exposed to harsh weather, but I've got a separate plasticiser and the blockwork will be covered in cladding anyway.

Thanks