BIAB Water Volume in 30L boiler (19L Batch)

[Pereubu]

Hi all.
I want to try doing BIAB and have a question about water volumes.
I have a Klarstein 30L Boiler, and I want to do a 19L batch.
The grain bill is approx 7kg
(6.35kg 2 row, 450g Crystal, 225g Carapils - Should I steep the Crystal and Carapils separately?)
I was thinking about the displacement of water from the grain.
SO. I would BIAB with 16L. And after that I would strain and sparge with whatever additional water
is required for my boil volume - so its a 90min boil, so 3L boiloff, and about 2L trub loss for 24L in boiler at start of boil.
Is this the best way to do this in my current setup?
Thanks all!

[Water_Wolf]

Sounds about right. Depending on the shape and amount of dead space in your mash vessel you may find that 16L of water is not enough for 7kg of grain and the mash will be too stodgy.

[Phil.cork]

Could you add 16l initially mash in and add more water at the right temp till full (noting how much) then top up after coming out. A 30 boiler may have 32odd litres capacity?

[Pereubu]

Thanks. I need to see how much volume the grain takes up, I think it is c 11l? If so I can biab with a bit more water.