Volume issues

I have used BeerSmith for my last several 12 gallon (10 gal packaged) batches.  Each time I am reaching the estimated pre-boil gravity (1.060) well before my desired volume (15.5 gal)  Last batch was 90 min boil.  I use the exact amount of water specified by BeerSmith (14 gal mash, 5 gal sparge) and it gets me to the pre-boil gravity perfectly.  However, why isn't it getting me to the correct boil amount?  I have looked at everything I can find/think of in Beer Smith.  Only thing I can think of is changing the grain absorption in the advanced preference settings but Beer Smith really recommends against that.  It is suggested to leave it at .96.  I don't want to add top up water to get boil or ferment volume.  I have never done that previous to Beer Smith and can't see how that would help as it would just off set my gravity in a negative way.  Is there a way to turn the top off setting off so it never tries to tell me to add water?  What is suggested? Not sure if I am asking all of the right questions but it's a starting point. Help is appreciated.

Hi,
If the boil volume is calculated (I'm assuming it is) the program works backwards from the batch volume (into fermenter) and then subtracts the various losses (boil off, trub loss, cooling, top up, etc...) to get to the boil volume.  Likely you need to adjust one of these to get a better boil volume.

Brad

Sorry Brad / All,

I just can't get this.  I think that all I really want to do is bump up the amount of sparge water that goes in with the fly sparge step on the brewsheet.  What do I need to change to increase that?  I have tried changing trub loss and boil off but they just throw off the whole recipe.  Increasing cooling setting gives more volume but is just tied in with more top up water.  What setting can I change so that I just get more sparge water to increase kettle volume.  I don't use top up.  Thanks.