I have had stone veneer and siding installed on my house from these guys. after the stone started falling from my house and the contractor wanted to accept zero responsiblity i had an Engineer investigate. Here is the response of the engineer.
At your request I visited the above noted site to inspect the installation of a natural stone masonry veneer
product manufactured by Realstone Systems. We understand the product is a Shadowstone panel in a
charcoal colour. In attendance were you, the homeowner, a representative of Realstone Systems, and a
representative of the installer. The inspection was carried out on July 20, 2011 at 9:00am.
The installation is principally comprised of corners and key architectural highlights on a two storey residential
structure. The masonry veneer elements are two stories in height on the sides and back of the building. The
balance of the exterior cladding is EIFS. We understand the installation took place last year and panel failure
occurred prior to the first freezing and thawing cycle. These panels were replaced using a construction
adhesive. Further panel failure occurred following the winter season.
The following observations were made;
1. The bedding mortar was not completely applied to the back of the
panel in all areas where the panels had been removed or fallen off.
In many areas the bedding mortar was not bonded to the scratch
coat. In visible areas the profile on the scratch coat was not
aggressive enough to promote bonding of the bedding mortar. In my
estimation on average only 75% of the back panel was buttered
with the bedding mortar.
2. The bedding mortar was not adhered well to the scratch coat and
contained many air bubbles. In some areas the bedding mortar also
fell off the scratch coat. It is reported that a type S mortar was used
with a latex bonding agent. Large inconsistencies in colour and
texture were noted at adjacent panels suggesting the addition of
water or poor mixing practice between panel installation.
3. To improve the bond it is reported that Weld-Crete® by Larsen
Products was applied to the back of each panel. This product
requires that it be applied in a thin uniform coat and allowed to dry
for one hour. It is apparent that the blue coloured residue from this
product remained on the bedding mortar. This typically results
when either the coating is too thick or has not dried sufficiently prior
to installation of the panel. Applied too soon, this product can
contribute to bond failure.
4. Voids behind the bedding mortar and scratch coat are a common deficiency in this installation and
could be identified by tapping with a medium sized rubber hammer. This deficiency also makes it
difficult to determine if the bond has failed at the panel to bedding mortar or at the bedding mortar to
scratch coat. It was suggested that some areas had 100% mortar
coverage. Accordingly, unlike the picture to the left where almost no
bedding mortar extended to the edge
of the panel, we investigated panels
where it appeared the bedding mortar
was complete and to the edge.
During removal of this panel by
tapping with a rubber hammer and
applying hand pressure, several panels fell from above. The degree
of vibration introduced during this removal does not warrant the
failure of the upper panels.
5. Large areas of tile have failed in a progressive manner. Voids
behind the bedding mortar indicate that the panel was not pressed
well with a slight rotating action on to the scratch coat. All exposed
areas had similar deficiencies described above that would contribute
to bond failure. Accordingly, it is our opinion that these areas are
representative of the whole installation. The last image shows all
conditions and in this area panels could be removed by hand. Given
the height of the installation this is a real safety concern.
We do note that the joints are tight and the quality of the cutting and joint placement is good. However; it is our
opinion that the bond failure is directly related to improper installation of the panels. Based on our
assessment we recommend that the entire installation be removed down to the scratch coat. The scratch coat
should be scored with a grinder to provide a more aggressive profile. Dependent on conditions it should be
pre-dampened 24 hours in advance of application of the bedding mortar and stone veneer panel. Unless
stringent conformance with the Weld-Crete® application requirements is followed, we do not recommend its
use. With careful removal most of the panels can be salvaged. The back of each panel should be cleaned
and be free of dust or materials that would negatively impact bond.
Caution during the removal should be exercised to avoid falling panels. This is best achieved by starting from
the top and working downward. Damage to panels will be reduced in this manner. If you have any further
questions please contact the undersigned directly.
Respectfully submitted,
Paul R. Walkington, CET, rcca, LEED®AP
Principal – Buildings Engineering
STANTEC CONSULTING LTD.
2781 Lancaster Road, Suite 200
Ottawa ON, K1B 1A7
Direct Phone: (613) 738 6088
Fax: (613) 738 0721
Email: paul.walkington@stantec.com
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