950SmileWay,York,PA17404|800.673.2408|
specifications | standard concrete masonry units
PART1—GENERAL
SUBMITTAL
Submitproductcertificationsandtestreports.
QUALITYASSURANCE
Certification: Concrete blocksfor finishing shall conform toASTM C90. The provisions of ASTM C90,apply with regard toappearance.
Fire Resistance: Define hourly ratings required as 1, 2, 3 or 4 hours; or as-needed or specified.
DELIVERY, STORAGEANDHANDLING
Masonry unitsshall be delivered to the jobsite on pallets or standard cube format. Store product in single stacks on level ground and cover withwaterproof covering (e.g., tarpaulins) to protect the blocks from inclement weather. Handleblockscarefullytoavoidbreakageand damage to the surfaces.
PROJECT/SITE CONDITIONS
Protection ofWork: Cover tops of walls each day after installation to keep open walls protected anddry.
PART2—PRODUCTS
PRODUCTNAME
Standard Concrete Masonry Units
MANUFACTURER
York BuildingProducts950 SmileWay, York, PA17404800.673.2408
RELATEDMATERIALS
Mortar isavailablefromWorkrite®. Refer toDivision 4 Masonry Section for mortar type and specifications.
SIZES AND SHAPES
Nominal 2", 4",6", 8", 10" and 12" standard block thicknesses areavailable, aswellasall standardblockshapes. High- strength units for special structural requirementsarealsoavailable.
MASONRY CLEANERS
Use masonry cleaners such as Prosoco Masonry Cleaner.Follow manufacturer’s instructions for proper mixing and
application. Do not apply cleaner with pressure spray above 50 psi. CAUTION!NeveruseMuriaticAcid solutionon units.Masonrycleaners are specified and to be used on architectural CMU only. No cleaners are needed on standard CMU.Rubbing & pointing of walls only, is required.
Part3—Execution
INSTALLATION
Layblocksfrommorethanonepalletatatimeduringinstallation.Lay units using the best concrete masonry practices. Layblocks with the faces level, plumb and true to the line strung horizontally at the face.Complete masonry construction usingprocedures and workmanship consistent with the best masonry practices.
Cutting: Make all unit cuts, including those for bonding, holes,boxes, etc., with motor-driven masonry saws, using either anabrasiveor diamondblade. Cutneatly andlocateforbestappearance.
Mortar Bedding and Jointing:
- Lay units withfull mortar coverage onheadand bed joints, taking care nottoblockcorestobegroutedorfilled
withmasonryinsulation.
- Tool all mortar joints -when thumbprinthard- into a concave configuration.
- Care should be taken to removemortarfromthefaceof masonryunitsbeforeitsets.
- Tuckpointthejointsofscored units for proper appearance.All exterior scored units must be tuckpointed to prevent waterpenetration. DO NOT USE RAKE JOINTS – UNLESS NOTED.
INSTALLATION RECOMMENDATIONS
- Cavity wall construction is recommendedforexterior walls, with proper flashing, venting and weepholes.
- Alwaystestasmall,inconspicuousarea before using cleaners.Do not use acids or abrasives on finished surfaces.
FLASHINGOFMASONRY WORK
Install flashing at locations shown in the plans and in strict accordancewith the detailsand the best masonry flashing practices.
WEEPS ANDVENTS
Installweepholesandventsatproper intervals (32" O.C.above bed joints, typical)atcoursesabovegrade, above flashingandatany water stopsover windows, doorsandbeams.
INSPECTION
The textured or ground facesshall be free from chips, cracks or any other imperfectionthat would detract from the overall appearance of the finished wall when viewed fromadistance of twenty (20) feetatrightanglestothewall withnormallighting.
CLEANING
Keep walls clean daily duringinstallation using brushes.Donot allow excess mortarlumps or smears to harden on
the finished surfaces. Harsh cleaning methods after walls have been erectedmay mar the surface of the blocks.
FINALCLEANDOWN
Clean the completed walls with masonrycleaner, strictly following the manufacturer'sinstructions--including thoroughrinsing. Do not useacid or abrasives on the finished surfaces. Failure to strictly follow manufacturer's instructions can result in permanentdamagetotheblockfaces.(Seenote on page 1 under Masonry Cleaners.)
MAINTENANCE
Properlyinstalledandcleaned architectural masonry unitsneed virtually no maintenance other than routine cleaning withstandard commercialgradecleaningagents.