Expert: Ted Barnhill (Principal, Design45 LLC) - 7/21/2008

Question
Hi Ted: I am building a new home in Regina, Sk Canada.My builder has used Typar housewrap  on the exterior of my home as a breathable sheathing membrane. The paper is supposed to be protected within 60 days from UV radiation.Our paper has been exposed for 280 days and the builder has suggested that he will cover it with Acrylic Sto stucco as a repair to the paper issue. Our building code clearly states coverage within 60 Days. Is Acrylic stucco the proper repair or dose the paper need to be replaced?

Answer
Kevin,

Let me be blunt.  Most would agree that acrylic stucco does not solve moisture infiltration issues, but instead creates and exacerbates them.  I agree that your housewrap has been exposed to UV, airborne dirt, and wind for too long - it needs to be replaced.  Do not apply acrylic stucco over a compromised membrane, or in fact over anything except a proper manufacturer-approved and tested water management system.  (In fact major window manufacturers are now stating that their warrantees are voided in synthetic stucco walls without an "engineered drainage system".)

Perhaps your builder meant that he will install such a system - a complete, moisture managed synthetic stucco system.  If so, I recommend removing the existing housewrap first - it is not the drainage plane, and it will impair your home's ability to dry out.  The installation details of flashing and drainage planes are critical - be sure that your builder or his subcontractor is properly trained on the exact system used, and that all steps are followed exactly per manufacturer specs.

I hope this helps.  Feel free to post any follow-up questions that you may have. -Ted