** Morningstar cuts James Hardie's JHX.AX fair value estimate by 5% to A$42, citing trimmed FY28 volume expectations and a weaker U.S. dollar (its reporting currency)

** Investment research firm maintains its view that the Azek acquisition remains "value-destructive", tempering its assessment of management's investment efficacy

** Expects net debt/adj EBITDA ratio exceeding 2 from FY26-FY28, versus a less than 1 for 3 yrs to FY25, despite some expected improvement

** Morningstar adds shares trade at ~35% below fair value, attributing the discount to market pessimism over cost-saving opportunities from Azek and near-term earnings expectations

** Stock slipped 9.9% in September, marking a third consecutive monthly loss

(Reporting by Kumar Tanishk in Bengaluru)

((Tanishk.Kumar@thomsonreuters.com; X: @thatstanishk http://www.x.com/thatstanishk))