American Hydrotech MM6125: The Perfect Roof.
The concept of placing the waterproofing membrane on the deck with insulation and overburden above
is the first step toward the perfect roof. It allows you to get the physics right. But the right membrane is
critical to making it a long term, problem free solution.
“MM6125 conforms to all surface irregularities and bonds tenaciously to an acceptable substrate (i.e.,
concrete, steel, wood, etc.) restricting the lateral migration of water between the membrane and
So, it’s fully adhered, right? There are other membranes and application methods I could choose to
achieve full adhesion.
In the 1990’s, the Director of Specifications for a respected, nationally based engineering firm prepared a
technical memo to address those trying to convince him to accept waterproofing products other than
company standard of Hot Fluid Applied Rubberized Asphalt, and specifically American Hydrotech’s
MM6125. In that memo he addresses his over 35 years of experience, over 4500 projects with
waterproofing membranes of all sorts, including a great variety of liquid and sheet membranes.
He had been involved in the investigation and analysis of many significant waterproofing failures over
the years and came to this conclusion:
“Endless analysis and reanalysis of these catastrophes succeeded at last in pounding into our
consciousness the infamous root cause for the endless failures of remedial procedures later applied to
rectify these situations, namely ‘subsurface migration’. In other words, despite the promises of an
endless list of promotors of ‘fully adhered’ sheet systems, like ‘the music goes round and round’ in the
old song, holidays in sheet adhesion led to the discovery of leak exits amazingly located at considerable
remove from the site of initial water entrance; enormous expenses were thereby incurred for
superfluous and unnecessary excavation, and in some cases demolition, simply to determine just where
the failures had happened.”
Their solution? “a thick layer of ‘sticky liquid’…placing the waterproofing coating directly on the affected
structure, where it belongs”, MM6125.
MM6125 goes on thick, in a hot, semi liquid state and is generally applied at a completed thickness of
215 mils, fabric reinforced. Although concrete prep and condition is always critical, MM6125 has
historically dealt with a wide variety of deck conditions and textures, filling all the voids, and building to
create a true continuously adhered waterproofing membrane with no voids.
“Restricting the lateral migration of water between the membrane and the substrate”.
A critical element that helps drive an unparalleled history of success over 60 years continues to drive the
wide use of MM6125 for roofs, vegetated roof assemblies, amenity decks and plaza applications.
A SIKA USA Company.