the following two last sets:
(#15) (TS=rot) OR (TS=mould*) OR (TS="fung*") OR (TS=moisture): 612.339
(#16) (TS="building product?") OR (TS="construction product?") OR (TS ="building material?") OR (TS ="construction material?"): 17.759
Since the five keywords above are very close and the intersection between the five sets of results are very little, we take the union of the five, obtaining a very big set of paper (#14). The intersection between set (#9) and (#14) is a reasonable number of papers (205, that doubles the intersection between (#1) and (#11), 104 papers): 
In the complete form, we write:
(#17) AND (#14) = [(TS="building product") OR (TS="construction product") OR (TS ="building material") OR (TS ="construction material")] AND [(TS="rot") OR (TS="rotting") OR(TS="mould") OR (TS="fungi") OR (TS="moisture")]205
Is this set of paper enough? we could restrict it with other key-words, like  "decay", "degradation", ... or "health", "sick building syndrome" and similar others, but the number is reasonable and we can look at everyone of the 205, reading its title and, if not clear, the abstract, to identify really interesting papers.