1. How is the product
made? What is the difference between Verastone and Verastone
recycled ground face masonry units are integrally colored
concrete blocks with one or more faces ground to expose the
variegated colors of the natural aggregates. A special additive
is included in the concrete mix design to prevent efflorescence.
A factory-applied, clear satin gloss acrylic accentuates and
highlights each burnished face and provides moisture resistance.
recycled filled and polished masonry units offer a smooth
terrazzo look on one or more of the faces. After the initial
grinding process to expose the variegated colors of the natural
aggregates, the pores and interstices are filled with a cementitious
grout. The exposed faces are then polished smooth in a multi-stage
polishing process and a factory-applied clear satin gloss
acrylic is applied to accentuate the natural beauty of the
aggregates and provide moisture resistance.
Verastone and Verastone Plus both contain a
significant amount of recycled content that may earn LEED®
points for your building.
2. Is the color on the
surface or all through the block?
The color is integral, i.e. it is uniform throughout
the concrete block.
3. Why is the color different
depending on which plant makes the blocks?
The aggregates used to make the blocks at each plant
come from different sources and are, therefore, of different
colors and particle shapes. This changes the color and appearance
of the finished product.
4. How can I be sure
it will not be chipped and scuffed in shipment and jobsite
Trenwyth takes great care in the manufacturing, packaging
and shipping of Verastone and Verastone Plus units to protect
the finished surfaces. The units are placed on sturdy wooden
pallets and a layer of heavy cardboard is placed between each
layer of blocks. The entire cube is then covered with a heavy
gauge plastic bag and strapped with steel banding. Verastone
and Verastone Plus units should be handled as finished material
on the jobsite to avoid scuffing, chipping or other damage.
5. Can I grind these
blocks at the jobsite?
No. Precision equipment is needed to grind and polish
Verastone and Verastone Plus units and this can only be done
satisfactorily in the factory.
6. Can any mason install
Any mason can install this product. Masons experienced
in laying architectural blocks who are good craftsmen can
lay ground face blocks very well. Unfortunately, no matter
how well our blocks are manufactured, if they are not laid
well, the appearance of the project is diminished.
7. What is the difference
between lightweight, medium-weight and normal-weight blocks?
ASTM C90 specification for load-bearing concrete masonry
units defines lightweight as concrete less than 105 lbs per
cu. ft., mediumweight as concrete between 105 and 125 Ibs
per cu. ft. and normal weight as concrete of 125 lbs per cu.
ft. or more.
The aggregate used to make lightweight blocks
is usually expanded shale, expanded clay, pumice or some similar
type of open-cell material. By its nature such aggregate is
porous and will allow some moisture penetration. ASTM C90
sets the maximum rate of absorption at 18 lbs per cu. ft.
for lightweight, 15 lbs per cu. ft. for mediumweight and 13
lbs per cu. ft. for normal weight. Most Verastone and Verastone
Plus units are medium-weight.
8. What is the surface
A clear high solids acrylic coating is applied in the
factory after the blocks are ground and polished. It is completely
light stable and will not deteriorate with exterior exposure
9. Why do you recommend
walls have a field coat? Is the field coating necessary?
The factory applied acrylic is designed primarily to
protect the Verastone and Verastone Plus surface during shipment
and installation. The field coat covers and enhances the entire
wall including the mortar joints and it hides most scuffs,
scratches and nicks that occur during handling and installation.
We consider the field coating necessary because it puts the
finishing touch to the installation and brings out the full
beauty of Verastone and Verastone Plus units.
10. What is the life
expectancy of the product?
50 years plus — if the building is properly designed
and the Verastone and Verastone Plus units are installed correctly.
11. At what temperature
should the TRENDCOAT® field coating be applied or not
The TRENDCOAT® coating should be applied to dry
walls when the temperature is above 55° F. It should not
be applied at temperatures lower than 55° F.
12. Will the TRENDCOAT®
coating peel, fade, crack or spall?
TRENDCOAT® contains the highest quality acrylic
available and will not peel, fade, crack or spall when properly
applied to a dry surface. However, if the walls are not properly
designed or constructed with appropriate flashing, weeps,
vents, etc., and the substrate block is continuously saturated
behind the acrylic, deterioration may occur over time.
13. Can you control the
Great care is taken in the Verastone and Verastone
Plus manufacturing processes to ensure a high degree of color
consistency. This includes checking incoming raw materials,
use of computer controlled precision automatic color injection
equipment, precise control of the moisture and curing process.
As with any natural product, there are minor color variations
from block to block. Final inspection includes dry stacking
samples drawn from the production line every half hour and
comparing those samples to the master sample for that project.
Always request a jobsite field panel to be erected to show
the expected unit and mortar color.
14. Can you match colors?
Yes, within the limitations of the aggregates available
at each of our plants.
15. If I want to put
on an addition a year or more after the original installation
of Verastone blocks, will the new Verastone blocks match the
We can usually match previously manufactured colors
quite well. However, we recommend that, if possible, a small
piece be cut or chipped from the existing wall and sent to
us. If that is not possible a new sample of the color should
be visually compared to the existing wall and adjustments
made to the color if necessary. Aggregates are a product of
“Mother Nature”, however, and can vary over time.
Always order a current full size sample to verify color.
16. What special precautions
should be taken in the handling, storage and installation
of the product?
Refer to the Verastone and Verastone Plus Installation
& Cleaning sections.
17. Can Verastone and
Verastone Plus units be used in flooring or paving?
No. Verastone and Verastone Plus units are designed
as wall material and are not suitable for flooring or paving.
18. How does one patch
this product? Can chips in the wall be repaired?
Damaged or chipped units that do not meet requirements
of ASTM C90 for the block should not be installed. If units
incur damage during installation or by other trades, a patch
kit can be ordered from Trenwyth Industries. Follow manufacturer's
instructions for best results.
19. Why should I pay
a for Verastone and Verastone Plus units when there
are so many other less expensive ground face blocks, split-face
blocks or bricks?
Verastone and Verastone Plus units are the highest
quality recycled ground face or burnished blocks available.
Trenwyth specializes exclusively in prefaced and prefinished
concrete masonry units. If quality and service are important
to you – you should specify and use Verastone and Verastone
20. What special shapes
are available? Can you provide bullnose corners? Are they
available in larger sizes?
A large assortment of special shapes are available
or can be made. We have numerous molds, jigs, etc. -- the
most in the industry. Give us a drawing or sketch of the special
shapes you would like and let us show you what we can do.
We offer a chamfered corner as well as a bullnose. A full
range of over-sized units are also available. See the Monumental
section of this site.
21. What do I use for
the washdown to remove mortar and scum?
Refer to the Verastone and Verastone Plus Installation
& Cleaning sections.
22. What happens if acid
is used on Verastone and Verastone Plus blocks?
Cleaners that use a harsh acid (like HCL) as a base
can attack the acrylic sealer, degrading the coating and etch
the pigment in the blocks. Use only the recommended cleaner
on Trenwyth products.
23. Are the blocks UL
Verastone and Verastone Plus blocks are tested annually
to Underwriter Laboratories (UL) standards by various independent
testing laboratories. Therefore, they are UL rated although
they are not UL listed, as there is no requirement that ground
face blocks be UL listed in the United States.
24. Can I return blocks
I do not use?
No. All Verastone and Verastone Plus blocks are custom
made. We require a signed sales contract before we will start
manufacturing any order. Since we don’t make any blocks
for stock, any Verastone and Verastone Plus blocks that are
ordered in excess must be shipped and cannot be returned.
25. Is the score cast
The score is cut into the finished side of Verastone
and Verastone blocks.
26. Can I get the back
side of the exposed, unfinished block scored to match the
score on the finished face?
27. Do I tuckpoint the
The scored joints must be tuckpointed to match the
rest of the mortar joints. If they are not tuckpointed, the
continuity between the scored joint and the mortar joint is
lost. Rake joints are not permitted on Verastone or Verastone
28. Is there any special
Colored mortar that matches or complements the Verastone
and Verastone Plus colors can create a beautiful effect.
For more information on mortars see Mortars
in the General Information section of our binder or call Trenwyth
and ask for Trenwyth Mortar Kit, TR0705. A Trenwyth-approved
integral water repellent admixture is recommended for all