Why Use A Rainscreen Drainage Mat?

Drainage Mat provides a permanent, predictable “Gap” of at least 1/8” and it provides the potential for air movement.

PUBLISHED BY: Masonry Technology, Inc..

POSTED: November 4, 2014

Since the 1990s the construction industry has become increasingly aware of the necessity of moisture management in the building envelope.   A great deal of research has gone into studying and alleviating the building envelope moisture issue, and it has all led to one simple answer:  There must be a permanent,  predictable drainage space located behind the veneer and in front of the moisture resistant material on the backup wall.  This space is known scientifically as a drainage plane and it is most effectively created by installing a product commonly referred to in the industry as a drainage mat.

So why use a drainage mat product behind your stucco, cultured stone (man-made) stone, thin brick, hardboard siding or other veneer?  Reputable scientists around the world have proven the necessity of a “gap” or “void” to the long term viability of the rainscreen building envelope.  Drainage mat products like MTI’s Sure Cavity, 10mm Sure Cavity and our economy Gravity Cavity rainscreen drainage mat (drainage plane) drain moisture down and out of the building envelope before it can damage sensitive materials.  The perforations in MTI drainage mat products also aid in airflow and their unique,” true channel” construction not only moves moisture down and out more efficiently, it also adds rigidity to our drainage mat products so they don’t collapse behind tightly fastened veneers.

MTI drainage mat (drainage plane) products have withstood the test of time.  We have been making rainscreen building envelope drainage products for more than 25 years, and MTI rainscreen drainage mat and masonry weep materials can be found in green building projects, fine homes and government buildings throughout North America.

Building Science – Including a Drainage Gap

Many scientific studies have taken place over the last 30-40 years related to building envelope (building enclosure) failures caused by moisture intrusion and with good reason.  According to the WBDG,  “Internal moisture degradation is a leading cause of premature failure of building envelopes.”1  As a result of these studies, experts like Dr. Joseph Lstiburek have determined that simply trying to keep water out isn’t enough.  Moisture will get into the building envelope through cracks and other imperfections in the veneer, and that water must be drained out.  The product created to handle drainage of the building envelope is a drainage mat. Read an overview of Dr. Lstiburek’s article “Mind the Gap, Eh!”

Rainscreen Drainage Mat Products, What’s Right for Me?

There are numerous drainage mat products on the market that claim to create a rain screen drainage gap.  Everything from furring strips to manufactured drainage mat (drainage plane) materials can be used to create “the gap” – what’s right for your project?  Discover the downside of furring strips. Learn how using the wrong weep screed in stucco or thin stone walls can defeat the work done by the drainage plane.

1Morse, Roger and Acker, Don. Indoor Air Quality and Mold Prevention of the Building Envelope, Morse Zehnter Associates, www.wbdg.org Last updated: 11-04-2014.

Save Money and Build Better with MTI.

Call 1-800-879-3348 or contact us.

Recent Articles

Compare MTI Drainage Mat Products

April 23, 2020

Flooded Wall Considerations

November 19, 2019

Newsletter Archive

Winter 2019 – Moisture Solutions for Adhered Stone

February 2, 2019

Fall 2018 – Continuous Insulation – Drainable & Durable

November 28, 2018