FREQUENTLY ASKED QUESTIONS

1. How is the product made? What is the difference between Verastone and Verastone Plus?
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.

Verastone Plus 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 handling?
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 this product?
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 coating?
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 and weathering.

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 applied?
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 color consistency?
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 old?
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 Plus units.

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 rated?
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 or cut?
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?
Yes.

27. Do I tuckpoint the scored joint?
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 Plus.

28. Is there any special mortar required?
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 exterior mortar.