MID america testing Laboratory
MATL opened in 1982 on a former Nike missile base outside St. Louis and spent four decades testing whether building enclosures do what the drawings say they will. Windows, doors, curtain wall, storefront, air barriers, skylights. Mock-ups before construction, installed systems in the field, and forensic work when something leaks and nobody knows why.
Rick Heitmann bought the company in 1991 and has been present at every formal test MATL has run since 1982.
In 2025, MATL joined G&W Engineering’s Building Enclosure Services group. Rick and his field technicians came with it, along with a new laboratory at G&W’s Maryland Heights headquarters.
Field testing puts a wall through weather it has not seen yet, under controlled conditions, and measures what gets through. Air infiltration is run at 6.24 PSF, with the specimen allowed .09 CFM of air leakage per square foot. Water testing uses a calibrated spray rack held at pressure for 15 minutes.
If Rick comes back with an A2LA or IAS certificate number, this section stays and names the accrediting body, the number, and the scope. That is a real credential and it belongs on the page and on the Enclosure box.
If there is no formal accreditation, delete this section entirely and add one line to section 05: “Testing is performed to AAMA, ASTM, and NAFS standards.” Accurate, still credible, no exposure. The page tightens to eight sections and nobody notices.
Do not repeat the press release language. “Fully accredited by AAMA, ASTM, NWWDA, and NAFS” is wrong. ASTM and NAFS publish standards, they do not accredit. NWWDA merged into WDMA in 1997.
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For four decades MATL ran on sixteen acres of a former Nike missile base, on a site built for one purpose: finding out what a wall assembly does under load before a building gets one.
That site did not come to G&W. The people did.
Rick Heitmann bought Mid America Testing Laboratory in 1991 and has attended every formal test the company has run since it opened in 1982. His field technicians came with him.
MATL joined G&W Engineering’s Building Enclosure Services group in 2025, and the testing now runs out of a new laboratory at G&W’s Maryland Heights headquarters. What changed is what sits around it. Air and water results land on the same table as the MEPFP, civil, structural, commissioning, and assessment work happening on the same building, with the same team. When a test finds a problem, the people who can solve it are already on the project.