Mechanically Fastened WRB vs. Liquid Membrane
I am a recent new homeowner. I purchased the home knowing that the stucco exterior, from ~1987, had some issues and would need to be redone over the next couple of years (worked into my negotiations). I got multiple quotes and am confident with the contractor that i chose. However, he has given me 2 options for the new system and i was hoping i could get some advice.
Basic home info:
-original structure is from 1956. An extension was placed in 1987 at which point the exterior stucco was redone. Upon investigation it seems like the person who installed it didnt not abide by the code from the 80s. There is between 5-7 inches of styrofoam behind the outer shell of stucco and there is no wrap between the styrofoam and the plywood. I have some areas concerning for rot.
-exterior surface is ~3000sqft
– i live in montreal, canada. a climate that has extremes of both cold and hot from -20C to 35C. I guess it would be considered average rainfall.
1) Tyvec system with anchors. Standard molding for doors and windows. 5 year warranty = 42000$
2) Liquid membrane system, standard moldings + flashings above all openings and at the bottom perimeter. 10 year warranty = 52000$
After reading some articles on this site it seems like the liquid membrane is clearly superior, but is it worth the cost?
is it superior as an air barrier and water barrier? Will it significantly help my energy costs? Does this system have a significantly better longevity then tyvec with anchors?
Any other advice would be greatly appreciated.
Thanks in advance
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