Masonry Magazine October 2002 Page. 21
QUALITY MASONRY TOOLS
KING BRICK HOO
WTOOLS
www.coorweldtools.com
4015 Creek Red House Springs, M. 6300
Рыми: (636) 671-4187 Fax (836) 375-3625
Toll Free: 1-800-245-2544
Grade Requirements for Face Exposures
| Exposure | Weathering Index |
|---|---|
| | Less than50 | 50 and greater |
| In Vertical Surfaces: In contact with earth not in contact with earth | MW MW | SW SW |
| In other than Vertical Surfaces: In contact with earth not in contact with earth | SW SW | MW SW |
| Table 1 | | |
initial rate of absorption. Physical properties required for proper performance are given in the appropriate American Society for Testing and Materials (ASTM) specification for brick.
Durability. Currently, there are two accepted methods for demonstrating durability under ASTM standards: 1) durability as predicted by compressive strength, absorption and saturation coefficient, or 2) durability as determined by compressive strength and passing 50 cycles of the freeze and thaw test. Specific criteria in each ASTM specification determine grade designations.
Brick is assigned a grade of severe, moderate or negligible weathering. Because of the varying climates experienced in North America and the great number of applications of brick, specific grades are required in many cases.
Figure 2 indicates areas of the U.S. with differing weather conditions. Table 1 defines where each grade is required. Most manufacturers make brick to meet the severe weathering (SW) grade so they may ship brick to all parts of the country. Some manufacturers produce brick complying only with the moderate weathering (MW) grade. Brick manufacturers can furnish certification that their product will meet a certain grade.
Absorption. Absorption can be broken into two distinct categories: absorption and initial rate of absorption (IRA). Both are important in selecting the appropriate brick.
Absorption of a brick is expressed as a percentage, and defined as the ratio of the weight of water that is taken up into its body divided by the dry weight of the unit. Water absorp-
Acceptance and Inspection of Brickc: The general contractor or mason contractor normally receives the brick when it is delivered to the job site. The general contractor or mason contractor should properly protect the brick from the weather and damage. It is critical that the contractor inspect the brick before it is placed in the wall. If there are any discrepancies, the manufacturer or distributor should be notified immediately.
The owner or a designated representative is responsible for acceptance of the work and, therefore, should inspect, as necessary, while the work progresses. This is especially critical at the start of the project to ensure that the color, texture and workmanship are representative of the sample field panel and is acceptable.
The selling party, whether the manufacturer, distributor or dealer, should visit the jobsite, and should be available for meetings and consultation in the event the owner or the owner's representative discovers a problem.
In the event the work does not meet with the approval of the owner or the owner's representative, the owner should immediately notify the contractor in writing, and appropriate action should be taken to correct the problem. If necessary, this may require that the work be stopped and that all interested parties meet to resolve the problem.
Do Include All Necessary Information When Ordering: All brick orders should be submitted by the purchaser, in writing, to the distributor or manufacturer, whichever is appropriate. The order should include and clearly identify the following job name and type; location; owner; architect; general contractor; material quantities (types and quantities of special or non-standard items should be accurately determined so that the order may be shipped in its entirety; brick should be described by actual dimensions rather than by generic or trade name; unit prices (including conditions such as escalation of prices); freight rates and terms; delivery schedules, including anticipated start date and rate of shipments; and other information pertinent to the order, such as a copy of that portion of the specifications which applies to the brickwork.
Do Use Detailed, Large-Scale Drawings if Special Shapes are Required: Detailed large-scale drawings should be supplied to the manufacturer through appropriate channels. Most orders are processed in a "chain of purchasing" that begins with the signing of the owner-contractor agreement and ends with the receipt of an order by the brick manufacturer. Other parties may be involved in this process as intermediaries or secondary parties, including, among others, the owner's representative, the contractor, the mason contractor and the distributor.
Each party in the chain should endeavor to promptly process the order and give approvals as necessary so as to cause minimal delays in the schedule of the project. Upon receipt of the order, the manufacturer typically acknowledges the order and should promptly advise the parties about any unacceptable or impractical terms.
It should also be understood by all parties that by placing a written order, the purchaser incurs the specific payment responsibility for all special and non-standard items.
The Voice of the Mason Contractor
October 2002
Masonry 19