Monday, September 13, 2010
IMPORTANT CHANGES TO MVMA GUIDELINES
The Masonry Veneer Manufacturers Association (MVMA) was organized and officially began operation in April 2006. MVMA represents manufacturers and suppliers of manufactured stone and brick veneer products.
The mission of the organization is:
"To advance the growth of the manufactured masonry veneer products industry through proactive technical, advocacy, and awareness efforts."
Instone is committed to making sure that we provide you with the knowledge and products to conform to current standards as well as possible future standards. MVMA recently made some changes to their guidelines relating to the installation of Cultured Stone®, ProStone® and other Thin Masonry Veneer products.
2-Layers of Weather Resistant Barrier
· 2 separate layers #15 felt (ASTM D226 No. 15, Type 1)
· 2 separate layers Grade D paper (ICC-ES Acceptance Criteria AC38
· 1 layer house wrap (ICC-ES Acceptance Criteria AC38 ) and 1 layer Grade D paper (ICC-ES Acceptance Criteria AC38), or #15 felt ASTM D226 No. 15, Type 1)
NOTE: One layer of paper backed lath meeting the requirements of Grade D paper may qualify for one layer of WRB
2.5 lb or 3.4 lb self-furred corrosion resistant lath (ASTM C847)
· Lath MUST be self-furred. This is an important change as self furred metal lath allows for better mortar embedment, enabling ¼" mortar behind the lath and ¼" mortar in front of the lath - completely encompassing the lath with mortar.
Alternative lath acceptable with Evaluation Entity evaluation acceptance report showing compliance to ICC-AC275
· Fiberglass lath is an acceptable alternative lath as it is compliant to ICC-ES Acceptance Criteria AC275
Weep Screed Systems
· For framed construction, corrosion resistant weep screed is required at the base of thin veneer installation.
To see the full guideline, click here http://www.masonryveneer.org/pdf/MVMAManualDesign_web.pdf
Coming soon from Instone
The future of Lath
Lightweight roll weighs 20 pounds (roll size 4' x 75' 300 sq ft roll) a roll is equivalent to 18 pieces of metal lath that weighs 90 pounds.
Big labor savings, up to 50% faster installation versus installing metal lath. As soon as you start attaching SpiderLath to the wall it's already going up twice as fast, since it's a 4' high roll versus a 28 inch high piece of metal lath.
Versatile and strong enough to use with heavy weight products such as three coat stucco and natural stone veneer and can handle up to 15 pounds per sq ft.