DAX 'If' statement with 'or' conditions

What if you have a multiples tables that need produce a Sum only if they have a value above 0 for example and I know this code isnt correct but im trying to explain

Calculate( Sum(
if Column 1 > 0,

if Column 2 > 0,

if Column 3 > 0)

How would I write something in the proper format in DAX

since i cant use if statements

This is what im trying to convert into DAX

SUM(iif((Fields.ADDTL_INST > 0
Or Fields.ADDTL_REF > 0
Or Fields.EXCISE_TAX > 0
Or Fields.RECORDING_FEES > 0
Or Fields.NON_STANDARD_FEES > 0)