Spectra-Glaze® Block FAQ Web Page

 Subjects Covered By Frequently Asked Questions
How to Specify | Cost | Cutting | Patching | Color Fastness | Custom Colors | Interior / Exterior | Fire Ratings | Burn | Graffiti | Double Face Alignment | Mortar | Will The Face Come Off


Masonry Industry Recommended Exterior Wall Design

  1. Full Flashing behind parapet wall.
  2. Roof system.
  3. 2" unobstructed airspace.
  4. Flashing with protruding drip lip.
  5. Flexible water-proof sealant around all window and door openings.
  6. Flashing
  7. Metal coping with 6" legs (shown), or pre-cast concrete or stone cap with adequate horizontal overhang and drip edge. Fixing dowels must be completly sealed at flashing performance.
  8. Weep joints or weep vents 1/4" wide (in joint) spaced as 32" O.C. immediately above flashing, bond beam, solid filled or other water stop locations in the wall, and at the top of the wall.
  9. Same as (8) eight.
  10. Concrete, metal or stone sill.
  11. Flashing with drip lip sufficiently protruding to direct water out and away from mortar joint and wall.
  12. Weep joints or weep vents 1/4" wide (in joint) spaced at 32" O.C. immediately above flashing, bond beam, solid filled or other water atop locations in the wall.






Most Frequently Asked Questions
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How should I write my specification?
Use the following paragraph as an example to specify Spectra-Glaze® Block:
Pre-Glazed Concrete Block
  1. "Spectra-Glaze® II Block", shall be manufactured under the license of Spectra Development Corporation, Baltimore, Maryland (410) 837-1810 Phone, 410-675-3684 Fax and shall be manufactured with SG ingredients.

    1. Pre-faced Surfaces: Smooth colored satin finish conforming to The Spectra Industries Inc., standards for interior or exterior use. Block must conform to ASTM C-744.
    2. Colors shall be selected from the full range of Standard, Designer&trade, Vari-Tone® or Custom Colors as supplied by Spectra Industries Inc.
    3. (Use if specifying SCORED block) Scoring surfaces shall be as indicated on Drawings. True and false mortar joints shall be raked and tuckpointed as shown in Spectra Insutries Inc., Spectra-Glaze® Catalog
    4. Concrete block for glazing shall be light-weight units to meet ASTM C90. Block sizes shall be modular, with thickness of 2 inches, 4 inches, 6 inches and 8 inches as indicated on Drawings.
    5. Shapes: Provide all necessary shapes needed to suit the conditions shown, including cove base, end and corner trim pieces.

  2. Mortar: (Specify)



What is the average Cost of Spectra-Glaze® Block?
The average cost of Spectra-Glaze® Block is $11.23 per square foot completly installed. This average was calculated as a 8x8x16 wall with 8x8x16 full return corners representing about 10 percent of the total glazed block and gives a good idea of stretchers and shapes combined. Labor, mortar and a profit markup of 20% are also included in this cost as provided by The 1998 Means Construction Cost Data guide. Other Spectra-Glaze® cornering systems such as the People FriendlyTM Series, Soft CornerTM Series, Trym SaverTM "A" Series or even a 4 inch return offer a reduction in cost since the cornering system used in this calculation is the most expensive cornering system offered. The lower cost are posted on each cornering system's web page.


What should I use to cut my Spectra-Glaze® Block?
Spectra-Glaze® Block is a Concrete Masonry Unit with a glazed faced integrally bonded to the block. Any method a mason may choose to cut a typical masonry block will also cut a Spectra-Glaze® Block. However, it is recommended that the Spectra-Glaze® Block be cut with a diamond blade to give the smoothest edge finish possible. An abrasive blade can also be used to cut the face of Spectra-Glaze® Block with good results.

It is best to use a saw which has an adjustable cradle for the straightest and smoothest cuts. Gasoline or electrical powered circular type saws will cut Spectra-Glaze®, but with the degree of difficulty in holding a straight line makes them a last choice.


Can Spectra-Glaze® Block be Patched?
Yes. Spectra-Glaze® Block can be patched with varying degrees of succsess depending on the size of the hole or chip and the skill of the technician. Best result can be achieved with chipped corners, impact dents from heavy objects or small misdrilled holes. However, a patch job is a patch job no matter how skilled you are at applying the patching material. Large holes or broken block should be replaced with another Spectra-Glaze® Block.

Patching small chips in the block which may have been caused by a chipped or broken block mistakenly put in the wall or damaged by other trades in the consruction prosess can be achieved by the following proceedure:


Make sure the area around the chip, dent or small hole is clean. For the patching material use an autobody filler such as Bondo to fill the hole. If the chip or hole is on the surface of the block rather than the edge of the block, a scraper troweled accross the area of the chip or hole can be filled. If the chip is on the edge of the block, you will need to apply tape across the edge of the chip and then apply the Bondo. You will need a very small trowel or something like an icecream stick to form the new block edge from the Bondo. If needed, the Bondo can be sanded with extra fine sand paper. Try to avoid sanding the Spectra-Glaze® Block. Have the Spectra-Glaze® Block color matched at a paint store with a Semi-Gloss Enamel Paint. Apply the paint over the patched area with a small fine artist paint brush. Remember, practice makes perfect, so you are better off taking a disgaurded piece of Spectra-Glaze® Block and practice patching a chip.



Are the Spectra-Glaze® colors "Color Fast"?
Yes. Each Spectra-Glaze® color is tested for its color fastness by South Florida Test Service with a 12 month exposure. Some colors tested better than other colors and are marked as so in the Spectra-Glaze® Catalog. Color Change in Spectra-Glaze® Block is also regulated by the standards of ASTM C 744 which contains the following requirments:

Color Change - Color change in Spectra-Glaze® Block will be determined by using several methods including CIELAB (1976) with a two degree observer, illuminant C, and specular excluded by the test methods given in ASTM D2244. Measurments must be taken before and after 500 hours of the Spectra-Glaze® Block being processed through accelerated weathering using a single-arc device by the test methods given in ASTM D 822. Test panels must not be less than 3 inches (76.2 mm) wide by 6 inches (152.4 mm) long. Test panels do not need to be conditioned.
As a result of meeting the standards given above it can be said that all colors will show at least some minor controlled fading on the exterior. However, the fading is slight and uniform. Spectra-Glaze® Block has been used on the exterior susessfully for more than 40 years. Make sure moisture in the walls can move and is not traped to ensure the best long lasting results in exterior color fastness. A construction detail of an exterior Spectra-Glaze® wall is giving on this web page and is also shown in the Spectra-Glaze® Catalog and Spectra-Glaze® Spec Data Sheet. It is recommended that you read the "Interior/Exterior" paragraph below.


Can I get a Custom Color?
Yes. Spectra Industries Inc., has the ability to match almost any color. Since the nature of Spectra-Glaze® Block is to have a satin finish, some glossy colors are more difficult to match perfectly. To get Custom Color in Spectra-Glaze® Block all you have to do is contact your local manufacturer or Spectra Industries Inc., to send them a sample of what you are trying to match. A sample can be back in your hands in two to three weeks. We can also handle rush jobs when your scheduled for a meeting with the owner to give your presentation.

There will no be no additional cost of the finished product if the total block ordered is more than 500 block. If the color match is for less than 500 block, a processing fee may be added.

If you want to check the long term color fastness of your custom color, we can accellerate the UV light impact with our weatherometer and give you a sample of the finished product.


Can Spectra-Glaze® Block be used on the Interior and Exterior?
Spectra-Glaze® Block can be used on the exterior or interior. Proper, lasting appearance and performance for all types of exterior masonry walls require correct design and consruction. The required construction procedures for Spectra-Glaze® Block include keeping wall dry during construction, tight joints, properly installed flashing, weep vents and coping to prevent water penetration and moisture retention in finished walls. A construction detail of an exterior Spectra-Glaze® Block wall is given on this web page and is also shown in the Spectra-Glaze® Block Catalog and Spectra-Glaze® Block Spec Data Sheet.


What kind of Fire Ratings can I get?
Since Spectra-Glaze® Block incorporates a concrete masonry unit as the foundation of the finished product, standard fire ratings of up to four hours can be achieved. Although you will have to check with your local manufacturer for their exact fire ratings, the following list provides typical fire ratings of Spectra-Glaze® concrete block:

Will Spectra-Glaze® Block Burn?
Spectra-Glaze® Block is strickly regulated by ASTM C 744 for its burning, flame spread and fume expolsion characteristics. Test methods are performed in compliance with ASTM E 84. The ASTM C 744 flame and smoke standard require the following:

Suface Burning Characteristics - Spectra-Glaze® Block must be tested in accordance to the test methods (of ASTM E 84), the Spectra-Glaze® surface shall have a flame spread not greater than 25 and must demonstrate no evidence of continued progressive combustion and shall have a smoke density rating not greater than 50.

As a result of meeting the above mentioned requirment, Spectra-Glaze® Block will not ignite with sometime as simple as a match, cigarette lighter or a typical trash can fire fuled by paper or simular products. To burn a Spectra-Glaze® Block you will need to create a torch enviroment within your building and maintain direct contact. If a torch is placed in direct contact with a Spectra-Glaze® Block, the block will show no effect for 35 to 60 seconds. Approximatly 45 seconds after the torch has been applied and held to one spot on the face of the block, the resin binders will break down. After the resin binders brake down there is nothing to burn. At this point the flame of the torch cannot spread past the 1/2 inch mark it left on the surface of the Spectra-Glaze® Block.

Since Spectra-Glaze® Block is not produced in the same way that glass or ceramic products are produced, they do not crack or shatter like glass or ceramic when a torch is applied to the face. As a result, the structural properties of a Spectra-Glaze® Block remain solid even if a catastrophic fire did take place in the building.


How well does Spectra-Glaze® Block withstand Graffiti and how is it removed?
The Spectra-Glaze® Block surface withstands graffiti very well. Graffiti can generally be removed using Spectra 100®, Spectra 310®, or Spectra 320® depending on the type of graffiti. Most commercial graffiti removers work well. Contact Spectra Industries Inc., or your local representative with specific questions. Never use abrasive objects like steel wool to clean the surface. Never use solvents such as methelene chloride or paint removers. Most paint removers contain some type of methylene chloride as an ingredient. Never use materials such as gasoline, turpentine or any materials designed to disolve oil base products.


How tight is the Double Face Alignment?
A Spectra-Glaze® Block can be aquired with two stretcher faces. This double faced unit is part of the "ST" series. The letter "S" stands for stretcher and the letter "T" stands for "two faces". To maunufacture a two faced block, the first face is produced and then the second side is applied later. Although each factory has devices which align the two faces, it is impossible to get them to align with each other consistently. There will be a slight variation between the two faces. Double faced units are a great way to save money and can be used with satisfactory results in areas where you can not stand back at a distant with the intent to critique the joint alignment. Areas like bathrooms, stairwells, tight hallways are a great place for double faced Spectra-Glaze® Block. When both sides of the way must have perfect joints, two single faced block are strongly recommended.


What type of Mortar should I use?
Since Spectra-Glaze® Block is a product integrally bonded to a standard lightweight concrete masonry unit, you can use any mortar that is typically consistent with the best concrete masonry practices as described in NCMA Tech Bulletins.


Will the Spectra-Glaze® Face Pop off of the block?
NO. Spectra-Glaze® Block faces are integrally woven into the pours of the block. Once the block leaves the ovens in the Spectra-Glaze® factories, it is forever part of the block and cannot be removed without destruction of the basic block. If you were to smash the block on the ground, the block would brake but the Spectra-Glaze® material would still be attached to the raw block.





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Southeast Capital Corporation, licensed users and master licensors are Spectra Development Corp.
and Spectra Industries, Inc. All rights reserved. Registered or Trademarks are property of
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