A one-part room temperature vulcanizable poly(diorganosiloxane) composition for a silicone elastomer air-water barrier coating for a building envelope, the composition comprising: (a) 10-70 wt% of a poly(diorganosiloxane) of Formula I: wherein R 1 and R 2 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6--10 aryl; and n has an average value such that the viscosity of the poly(diorganosiloxane) of Formula I is from 40-90 Pa.s (40,000-90,000 cP) at 25°C as determined using a Brookfield viscometer according to ASTM D4287; (b) 5-40 wt% of a poly(diorganosiloxane) of Formula II: wherein R 3 and R 4 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; R 5a, R 5b, R 5c, R 5d, R 5e and R 5f are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; and q has an average value such that the viscosity of the poly(diorganosiloxane) of Formula II is from 0.5-50 Pa.s (500-50,000 CP) at 25°C as determined using a Brookfield viscometer according to ASTM D4287; (c) 0.5-25 wt% of an amorphous silica reinforcing filler; (d) 2-15 wt% of at least one cross-linking agent of Formula III: 4-m -Si-R 6 m wherein R 6 is C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; m is 0, 1 or 2; and X is a hydrolysable ketoximino-containing group of Formula IV: wherein R 7a and R 7b are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; or X is a hydrolysable group of Formula V: wherein R 8a, R 8b and R 8c are each independently H, C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; (e) 0.2-5 wt% of an adhesion agent of Formula VI: wherein R 9 and R 10 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; R 11 is C 1-10 alkyl, C 2-10 alkenyl or C 6-10 aryl, optionally substituted with one or more organofunctional groups; and p is 0 or 1; (f) 0.01-2 wt% of an organometallic condensation catalyst, wherein the metal of the organometallic condensation catalyst is selected from tin, titanium, zirconium, boron, zinc and bismuth; (g) 1-40% of a solvent selected from an organic solvent and a methylated silicone solvent, wherein each alkyl, alkenyl and aryl group in the compounds of Formula I, II, III, IV, V and VI is optionally halo-substituted. (a) 10-70 wt% of a poly(diorganosiloxane) of Formula I: wherein R 1 and R 2 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6--10 aryl; and n has an average value such that the viscosity of the poly(diorganosiloxane) of Formula I is from 40-90 Pa.s (40,000-90,000 cP) at 25°C as determined using a Brookfield viscometer according to ASTM D4287; R 1 and R 2 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6--10 aryl; and n has an average value such that the viscosity of the poly(diorganosiloxane) of Formula I is from 40-90 Pa.s (40,000-90,000 cP) at 25°C as determined using a Brookfield viscometer according to ASTM D4287; (b) 5-40 wt% of a poly(diorganosiloxane) of Formula II: wherein R 3 and R 4 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; R 5a, R 5b, R 5c, R 5d, R 5e and R 5f are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; and q has an average value such that the viscosity of the poly(diorganosiloxane) of Formula II is from 0.5-50 Pa.s (500-50,000 CP) at 25°C as determined using a Brookfield viscometer according to ASTM D4287; R 3 and R 4 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; R 5a, R 5b, R 5c, R 5d, R 5e and R 5f are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; and q has an average value such that the viscosity of the poly(diorganosiloxane) of Formula II is from 0.5-50 Pa.s (500-50,000 CP) at 25°C as determined using a Brookfield viscometer according to ASTM D4287; (c) 0.5-25 wt% of an amorphous silica reinforcing filler; (d) 2-15 wt% of at least one cross-linking agent of Formula III: 4-m -Si-R 6 m wherein R 6 is C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; m is 0, 1 or 2; and X is a hydrolysable ketoximino-containing group of Formula IV: wherein R 7a and R 7b are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; or X is a hydrolysable group of Formula V: wherein R 8a, R 8b and R 8c are each independently H, C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; R 6 is C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; m is 0, 1 or 2; and X is a hydrolysable ketoximino-containing group of Formula IV: wherein R 7a and R 7b are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; or X is a hydrolysable group of Formula V: wherein R 8a, R 8b and R 8c are each independently H, C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; (e) 0.2-5 wt% of an adhesion agent of Formula VI: wherein R 9 and R 10 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; R 11 is C 1-10 alkyl, C 2-10 alkenyl or C 6-10 aryl, optionally substituted with one or more organofunctional groups; and p is 0 or 1; R 9 and R 10 are each independently C 1-8 alkyl, C 2-8 alkenyl or C 6-10 aryl; R 11 is C 1-10 alkyl, C 2-10 alkenyl or C 6-10 aryl, optionally substituted with one or more organofunctional groups; and p is 0 or 1; (f) 0.01-2 wt% of an organometallic condensation catalyst, wherein the metal of the organometallic condensation catalyst is selected from tin, titanium, zirconium, boron, zinc and bismuth; (g) 1-40% of a solvent selected from an organic solvent and a methylated silicone solvent, wherein each alkyl, alkenyl and aryl group in the compounds of Formula I, II, III, IV, V and VI is optionally halo-substituted.