SECTION 04220 - CONCRETE UNIT MASONRY
NOTES TO SPECIFIER
General notes about the specifications and the reasons
for them are listed here in general statements. Use this as a guide
when choosing the correct selection of statements that apply to
your job from the actual specifications.
A.S.T.M. C-90-96, UBC Standard 21-4
These specifications are based on A.S.T.M. C-90 - Latest Edition. When particular
features are designed such as weight classification, higher compressive
strengths, surface textures, finish, color, fire resistance, insulation,
acoustical properties, or other special features; such properties
should be specified separately and clearly by the purchaser or architect.
However, Orco Block should be consulted as to the availability of
units having the desired features.
TYPE OF BLOCK
Selecting the proper type of block for your job is very important.
Texture means you are using slump block, split face, or precision
block. Specify and indicate the proper type or types to be used
and their locations.
A sample panel is important because it serves as a visual aid for
workmanship for the masonry contractor and architect. This helps
to eliminate later discussion about workmanship standards. In lieu
of the sample panel, begin work in the most obvious section designated
by the architect and this will serve as the sample panel.
Specify being a participant in the Q block test program because
this is the way the owner and architect are sure they are getting
a quality manufacturer who is tested every quarter rather than every
year as the A.S.T.M. requires. Also in the Q block test program,
the blocks are picked up from a job site rather than from the plant
once a year as the A.S.T.M. requires. The companies who participate
think enough of their product to pay or these additional tests themselves
and are competitive with the manufacturers who do not participate.
Colored block usually has to be manufactured, especially on large
products. It is also one of the first items to be installed. To
avoid a possible delay in construction, select the block color before
bidding the job. This will take the guesswork out of the bidding
process because the cost of color in block does vary. This also
alerts the general contractor to notify the masonry contractor,
who in turn should be expedient in placing the order with his supplier.
ORCO BLOCK COMPANY’S SUGGESTED BLOCK MASONRY
SECTION 04220 - CONCRETE UNIT MASONRY
Conditions of the Contract and Division 1 General
Requirements are a part of this section.
A. Provide materials, labor and equipment necessary
for the completion of concrete masonry work as indicated on the
drawings and specified herein.
1.02 RELATED WORK SPECIFIED ELSEWHERE
A. Section 07180- Water Repellents
B. Section 08100- Metal Door Frames
C. Section 09200- Plaster
D. Section 09250-Gypsum Wallboard
1.03 CODES AND STANDARDS
A. Perform work with materials complying with ASTM,
UBC and NCMA specifications.
A. Conform with the requirements of Section 01401- Testing and Inspections.
A. Submittal procedures and quantities are specified
in Section 01300-Submittal.
B. Submit copies of manufacturer’s product information
and installation instructions for each item and accessory.
C. Submit samples of exposed masonry units, indicating special shapes,
textures and colors.
D. Expansion Joint and Control Joint Materials: Provide
samples and Catalogue data.
1.06 JOB CONDITIONS
Do not lay masonry when the ambient temperature is
below 40 degrees F. or when it is likely that the ambient temperature
will fall below 40 degrees F. during, or within 24-hours after masonry
1.07 QUALITY ASSURANCE
A. Subcontractor Qualifications: Only skilled, first
class masons shall be employed for masonry work. The Masonry Subcontractor
shall have a minimum of six (6) years experience in masonry work
of the type indicated for this project.
B. Coordination with other Trades: Coordinate masonry
work with other trades that interface with the masonry work or that
require penetration Through or attachment to masonry.
C. Mock-Ups: Before installation of concrete masonry erect one sample
panel as follows:
1. One panel shall be constructed to simulate the
condition of concrete masonry walls. The panel shall be 8 feet long
by 4 feet high and shall show the proposed color, texture, bond,
pattern, mortar joints and workmanship for concrete masonry. Mock-up
panel shall be constructed on “pallets” so it may be
relocated as directed.
2. Upon approval by the Architect, the sample panels
shall become the standard of comparison for concrete masonry construction.
After concrete masonry construction has been completed, remove sample
panels and dispose of debris off the site.
PART 2 PRODUCTS
2.01 CONCRETE UNIT MASONRY
A. Load bearing smooth face (light, medium, normal)
weight concrete masonry units shall comply with ASTM C-90-96, UBC-21-4
(Type I or Type II). Provide required shapes such as corner, end
units, radius bases, bond beams, lintels, etc. Provide units open
one or both ends, as required. Maximum linear shrinkage shall be
.065% from standard oven dry condition. Concrete masonry units shall
have a minimum net compressive strength of 1900 psi.
B. Masonry units shall be manufactured by Orco Block
Company, Inc., or approved equal by Architect. Provide the following
types of concrete masonry units:
1. Precision block
2. Splitfaced block
3. Slump block
4. Burnished block (Factory finishing process shall
remove not more than 1/16" face of block exposing aggregate
and cement leaving a smooth, flat, and level face, free of saw cut
or other lines marring the face of block, and match sample in Architect’s
Office. The use of sawing cutting block face is not acceptable.)
5. Orco Shotblast (Factory sandblasted finishing process
shall remove cementitious face of block exposing aggregate and cement,
leaving a medium texture to match sample in Architect’s Office.
The use of field sand blasting of block face is not acceptable.)
6. OrcoBurst (Variegated Block shall have factory
blended colors. Manufacturing process shall blend two or more separate
colors, as selected by Architect, in random proportions within blocks
to produce units with the each color marbled fully and continuously
throughout. The use of post applied surface stains, paints or pigments
on face is not acceptable.)
7. Sound block
8. Interlocking block
9. Veneer block
10. Expandable block
11. Other (Call Your Orco Representative for expanded
C. Block colors shall be as follows or selected from
manufacture’s standard colors.
2.02 MORTAR AND GROUT COMPONENTS
A. Cement: Cement shall be portland cement conforming
to ASTM C-150, Type I, II, III (UBC 19-1).
B. Aggregates: Aggregates for mortar conform to ASTM
C-144. Aggregates for grout conform to ASTM C-404.
C. Lime: Hydrated lime shall conform to ASTM C51 (UBC
D. Water: Clean and free from deleterious substances.
E. Sand: Comply with the “Standard Specifications
for Aggregate for Masonry Mortar”, ASTM C-144, except provide
natural sand graded From coarse to fine within the following limits:
Passing No. 4 sieve 100%
Passing No. 8 sieve 95% to 100%
Passing No. 16 sieve 70% to 100%
Passing No. 30 sieve 40% to 75%
Passing No. 50 sieve 10% to 35%
Passing No. 100 sieve 3% to 15%
F. Pea Gravel: Graded with 100% passing the 3/8"
sieve and not more than 5% passing the No. 8 sieve.
G. Package Materials to be delivered and stored in
original packages until ready for use. Store cement, lime and aggregates
in a manner which prevents deterioration or contamination.
H. Do not use material which is caked, lumpy, partially
set or otherwise deteriorated.
2.03 MORTAR AND GROUT MIXES
A. Mortar (ASTM C-270, UBC 21-15):
1. Type S Mortar: 1 part portland cement; 1/4 to ½
part lime putty or hydrated lime; 2 1/4 to 3 times to sum of the
volume of the cement and lime used. (Average compressive strength
at 28 at days shall be 1800 psi.)
B. Grout (ASTM C476, UBC 21-19): 1 part portland cement;
2 1/4 to 3 damp loose sand; 1 to 2 parts course aggregate.
1. Sufficient water shall be added to make a workable mix that will
flow into joints of masonry without separation or segregation. When
grout is to be placed in masonry units with typical rates of absorption
the slump of the grout should be approximately 8 to 10 inches depending
on temperature and humidity conditions.
2.04 REINFORCING STEEL
A. Reinforcing bars shall comply with ASTM A615, Grade
60, except that Number 4 and smaller bars shall be Grade 40.
PART 3 EXECUTION
3.01 GENERAL WORKMANSHIP
A. Lay block in running bond with mortar for bed joints
flattened, furrowing of bed joint mortar will not be permitted.
Head joints solidly filled with mortar for a distance in from the
face of the wall or unit not less than the thickness of the longitudinal
face shell. Shove blocks into place to compact the head joint mortar
and improve the bed joint. Vertical cells shall have vertical alignment
sufficient to maintain a clear, unobstructed continuous vertical
cells for grouting. Remove overhanging mortar and debris from cells
before grouting. Install hollow metal frames as indicated.
B. Accurately place reinforcing steel as shown on
the drawings, positively secured and supported in such a manner
that no movement occurs when the grout is poured. Reinforcing and
tie wires shall be embedded in the grout. The thickness of the grout
between masonry units and reinforcing shall be a minimum of one
C. Damp cure masonry work for a period of not less
than 7 days after the work is completed. Make visions for curing
on Saturdays, Sundays and Holidays.
D. Replace defective blocks and blocks cut when cylinder
is removed with new masonry which matches the existing.
1. Exposed vertical and horizontal joints shall be solidly filled
as the work progresses. After joints are thumb print firm, they
shall be tooled to a tight, smooth concave surface with an approved
tool. Joint width shall be 3/8" inch, 1/2" for slump block.
2. Control of expansion joint shall be continuous through the mortar
and masonry, at a maximum of 40'-0", unless shown otherwise.
Horizontal reinforcement, except at roof or floor diaphragm, shall
be continuous through the control joint.
A. Top of grout pour should be kept damp to prevent
too rapid drying during hot or drying weather and drying winds.
A. Immediately after the wall has been fully grouted,
the scum and stains which have percolated through the blocks and
joints shall be hosed off with low pressure water through a jet
B. Keep area clean and neat. After completion of grouting,
clean up and remove resultant debris from the site.
- END OF SECTION -
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