As a waterproofing contractor specializing in failure, I give little merit
to manufactures and their claims regarding the durability or longevity
of their deck coating assemblies. All these assemblies have issues and
the proof is seen in the photos below which were taken from inspections
DeckTech, Inc. has provided to our clients. The key to a durable and long-lasting deck
is finding an assembly that meets the specific needs of the project environment
and then ensuring fundamentals are sound prior to any application.
Acrylic Coatings
The Acrylic Cement coatings Life Deck, Desert-Crete, West-Coat and numerous
others, all fail here on the coast. The expanded hot dip metal lath will
rust out, the hot dip protective coating is immediately impacted upon
installation when lath is cut and stapled. The lath is rarely stapled
to manufactures spec. 22-28 staples per square foot and as lath moves
around due to this deficient stapling & Expansion /Contraction of
substrates, the acrylic cement is very ridged and fractures. Once you
have a fracture in this assembly the moisture enters into lath and then
cannot escape. The lath then accelerates with rust and loses additional
tensile strength accentuating even more fractures. This condition then
leads to total failure and excessive moisture intrusion. The end.
Urethane Coatings
The Urethane direct bond or lath systems Tuff-Flex-Plydeck/MA-Coat are
thin wall coatings and many have flashing strips installed over plywood
seams. Others have diamond lath. The thin wall coating actually will make
flashing sweat, because coating thickness is so thin it allows a certain
amount of condensation to enter flashing details in damp environments
(Coastal Region) These systems all have issues with flashing failure.
The other deficiency we typically see is telegraphing of all plywood seams
and nailing. All these assemblies fail at the plywood seams, nailing and
flashing edges.
Neoprene Coatings
The Slip-Sheet deck coating Merkote Weather-Deck is a soft Neoprene and
as photos indicate they dent and ding easily if items are dropped on them
or furniture moved around on them. They also have chronic issues with
nail heads backing out and penetrating through the coating. This assembly
has been in use for years but very outdated due to new technology in the
coating industry. This assembly needs a lot of TLC and if not given this
attention will fracture and fail.
Respectfully,
Ron J. McKenna
DeckTech, Inc. President