HEO Architects
TECHNICAL SPECIFICATION
MASONRY WORKS
1.00
GENERAL
1.01
SCOPE OF WORK
The work under this section shall include all labor, materials, equipments,
plants and other facilities and the satisfactory performance of all works
necessary to complete all masonry and other cement work shown in the
drawings and specified herein. All works included under this section shall be
subject to the General Conditions accompanying these specifications.
1.02
PRODUCT HANDLING
a.
Deliver masonry materials, other than bulk materials, to project site in
manufacturers, unopened containers or other standard packaging, fully
identified with name, type, grade, color and size.
b.
Store on platforms and protect from weather, soiling and damage.
c.
Protect masonry from rain until the work is complete and the mortar has set.
Protect with strong waterproof membrane well secured in place, or other
suitable protective materials.
d.
Handle products in a manner to prevent chipping and breakage.
1.03 QUALITY ASSURANCE
a.
Sampling and Number of Specimens
1.
Specimens shall be representative of the whole lot of units from which
they are selected. If a test specimen is selected at the site of the work,
units for moisture content tests shall be taken within 48 hours after
delivery.
2.
In Sampling the blocks for the strength, absorption and moisture
content determination, 10 individual units shall be selected from each
lot of 10,000 units as fraction thereof and ten (10) individual units shall
be selected from each 50,000 units or fraction thereof contained in the
lot.
3.
These samples shall show the extreme variation in size and in color
that may occur in the material furnished in the field.
4.
All material furnished shall fall within range of the approved samples.
5.
No material shall be sent to the job site until the samples have been
approved.
b. Testing
Method of testing masonry units of:
1. American Society for Testing Materials (ASTM) designation C-149
2. Division of Materials Testing and Physical Research, Ministry of
Highways, Manila.
Note: No blocks shall be used unless the results of tests are known and
duly approved by the Architect.
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In case the shipment of CHB fails to conform to the requirements,
the manufacturer may sort it and new specimen shall be selected
again at random from the retained lot and tested at the expense of
the contractor. In case the second set of specimen fails to conform
to the test requirements the entire lot shall be rejected.
1.04 SUBMITTALS
a. Submit samples of each type of masonry unit for acceptance of size color
and texture only. Compliance with other requirements is the responsibility of
the Contractor.
b. Submit manufacturers specifications, with certified copies of laboratory test
reports and other data as may be required to show compliance with the
contract documents for each type of masonry supplied.
c. Submit dimensioned shop drawings showing the layout, details and
reinforcing for brick soffits and lintels. Comply with ACI-315 Manual of
Standard. Drawings shall bear the seal of a licensed Professional Engineer
registered in the Philippines.
2.00
PRODUCT
2.01 MATERIALS
a. Mortar
Cement mortar shall be 1 part and 3 parts coarse sand (by volume). Add
water to produce a good workable mixture. Water should not be more than 9
- 12 1/2 (by weight) depending on water content of sand and the weather. If
more water is required, the sand should first be tested to determine if there
are foreign injurious matters to the mortars of the mixture.
Cement mortar shall be mixed by cement and only if such mixer and only in
such quantities as are required consistency has been obtained. Retempering and/or remixing of cement mortar that has partially hardened shall
not be allowed.
b. Concrete Hollow Block
For walls and partitions shown in the drawings requiring concrete hollow
blocks, the Contractor either uses Concrete or louver blocks upon approval
of the Architect. The load bearings of higher blocks shall have a minimum
compressive strength of 1,000 lbs. per square inch computed from the
average of five (5) units based on the average gross area, and a minimum of
800 lbs. per square inch for the individual unit. For the non-load bearing
hollow blocks, 350 lbs. per square inch for the individual unit respectively.
Masonry Works
1.
All CHB shall extend up to the bottom of the beam or slab.
2.
Use 700 psi for all CHB thickness.
3.
All CHB walls shall be with stiffener column at every 4.00m o.c. with 412mm dia. vertical bars, 10 @ 0.30m o.c. stirrups. Lintel beams on top
(0.15m x 0.30m) with 4-12mm dia. and 10mm dia. @ 0.30m o.c.
stirrups.
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TECHNICAL SPECIFICATION
4.
Verify CHB thickness as indicated in the plan.
c. CHB Reinforcements:
c.1) Vertical Bars- 12 mm dia. @ 0.60 m o.c.
c.2) Horizontal Bars- 12 mm dia. @ 0.60 m o.c.
c.3) Minimum Lap @ splice 0.20 m
c.4) Provide right -angled reinforcement on corners @ 0.90m long
c.5) Where CHB wall adjoining column R.C. beams and walls dowel with the
size @ vertical or horizontal, reinforcement shall be provided.
c.6) The minimum dowel length shall be 30 times the diameter of the bar.
d. Aggregates:
d.1) Lightweight: ASTM C331; Haydite, Norlite, Solite or Waylite: producing a
concrete density not exceeding 95 lbs. per cu. ft.
d.2) Normal weight: ASTM C33, concrete aggregates producing units with a
dry net weight of not less than 125 lbs. per cu. ft.
e. Anchors and Ties:
A-151 Type 302 or 304 Stainless steel wire of acceptable design, complying
with the following requirements:
e.1) Wire Ties: ga.10 looped at both ends
e.2) Wire Mesh Ties: ga. 16, 1/2 in. mesh, 3 in wide
e.3) Joint Reinforcement: Truss type, fabricated from ga. 9 cold drawn Type
302 or 304 stainless steel wire complying with ASTM A82; deformed
side rods; smooth cross rods; out to out spacing of side rods
approximately two (2) inches less than nominal wall thickness.
e.3.1 At cavity walls, provide (brand) with drip ties, or approved equal.
e.3.2 At Spandrel beams, provide and adjustable type joint reinforcing,
(brand) or approved equal.
f.
Control Joint Filler- Extruded rubber, ASTM D20 00, Type R, Shore A
Durometer 60 to 80 size and shape as shown and closed cell neoprene.
ASTM D1056, Type S, Class SCE, or size and shape to suit location.
g. Flashing: Neoprene sheet, 1/6 inches thk. unless otherwise shown. (brand)
Provide primer, adhesive and sealant for flashing as recommended by the
flashing manufacturer.
h.
3.00
Porous Filter:
(brand).
Vinyl plastic open cell sponge material.
10 pores per in
EXECUTION
3.01 INSTALLATION
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a. Lay masonry plumb, true to line with level and accurately spaced courses;
corners plumb and true; each course breaking joint with the course below,
except as otherwise shown. Maintain plumb bond. Variations from plumb, true
or level of more than 1/8 inch in 8 feet in any direction will be accepted.
b. Anchor, tie, reinforce and bond masonry at corners and intersections in
accordance with the applicable requirements of governmental authorities
having jurisdiction.
c. Step backs unfinished work for joining with new work; tooting is not permitted.
Before new work is started, remove all loose mortar.
d. No cracked, chipped, broken, discolored, defaced or open celled unit will be
permitted on masonry.
e. Perform cutting, patching and repairing of masonry work as required to
accommodate the work of other trades.
f.
Use powered carborundum saw to cut concrete masonry units with clean
sharp corners to provide pattern shown and to fit adjoining work neatly. Use
full units without cutting wherever possible. Avoid the use of less than halfsize units in exposed locations.
g. Tool exposed joints slightly concave unless otherwise shown. For surfaces to
be plastered, rake joints to obtain bond. Lay masonry unit with uniform joint
widths. Tool joints to squeeze mortar back into joints. Tool after mortar has
taken its initial set. At inside face of exposed masonry air shafts, strike joint
flush.
h. Install flashings in masonry work to drain water to the exterior. Place flashing
on mortar bed and cover with mortar. Overlap ends 3 inches extend over
lintels and terminate 1/2 inch from face of wall. Seal flashing joints using
materials and methods recommended by the flashing manufacturer.
3.02 LAYING CONCRETE MASONRY UNITS:
a.
Erect concrete masonry units where shown. Solidly bed each course in
mortar. Butter vertical joints their entire length. Bond each course at corners
and intersections and bond into or anchor to adjacent construction with metal
anchors spaced not over 32 inches on center both ways.
b. Set units with care around frames so as not to bulge the sides or change
position of the frames. Break joints in units set around the tops of
doorframes. Set units tightly against metal frames and fill voids completely.
Build frame anchors into joints. Cut units accurately to fit around pipes, ducts
and openings, and fill voids full. Fill jambs and heads of hollow metal frames
solid with mortar.
c. Build partitions of thickness shown. Allow other trades to install built-in work
before proceeding with the partitions. Leave openings where required; such
openings to be closed up later. Lay first course with cells vertical and fill cells
with mortar to one-half the height of the unit. Construct masonry partitions up
to a control joint at underside of structure above, unless otherwise shown.
Rake mortar joint at top of walls in exposed locations 1/2 inch for sealing
specified under the section entitled Sealants. Concrete masonry units
enclosing toilets and other spaces where shown shall have cells filled with
sand.
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TECHNICAL SPECIFICATION
d. Line up courses of exposed work to obtain a uniform appearance. Install units
where conduits, pipes or ducts are to be enclosed to maintain the pattern.
Neatly drill holes in exposed units for attachments of handrail brackets and
similar items. Provide necessary special shaped units where required to
maintain the pattern.
e. Joint requirements: Place joint reinforcement in horizontal joints on 16 in.
centers. Make reinforcements continuous except at control joints. Lap
reinforcement 6 inches at ends and use pre-fabricated T and L sections at
corners and intersections to provide continuity. Provide reinforcement in first
and second joints above lintels and below the sills, extending 2 feet beyond
each side of opening.
f.
Control Joints: Construct continuous control joints to provide an unbroken
separation through the entire thickness of walls, as detailed and at locations
shown. Where locations are not shown, construct vertical control joints at
approximately thirty (30) feet centers. Brace tops of partitions at horizontal
control joints below the structure with angle clips of adequate size and
spacing.
g.
Lintels:
g.1) Provide lintels of specially formed masonry units, with reinforcing bars and
mortar fill, where shown and where openings in concrete masonry of more
than 1 ft. are shown without steel lintels. Unless otherwise shown provide
one bar for each 4 inches thickness of wall, and use bars of a size number
not less than the number of feet of opening width. Provide minimum lintel
bearing of 4 inches openings up to 6 feet and 8 inches for openings over 6
feet. Pre-cast lintels or form lintel in place with adequate temporary support.
Cure pre-cast lintels thoroughly before handling.
g.2) Provide stiffener column for CHB walls within span of more than 4 meters.
g.3) Provide Lintel beams: (see Structural plans)
c.1 for CHB walls with height of more than 4.00 m
c.2 for CHB walls not extending up to the slabs or beams
c.3 for door and window header openings
c.4 for counter slabs
h. Install steel lintels and lintels of other materials as indicated on drawings.
3.03 BUILT-IN WORK:
a. Build in miscellaneous metal and other items of work furnished under other
Sections. Build in and protect flashings, reglets, anchors and other similar
items in masonry. Set and grout loose lintels. Provide anchors required
exclusively for masonry work.
b. Install access doors, frames and access panels occurring in masonry
construction where shown and required for access to mechanical and
electrical installation and equipment.
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TECHNICAL SPECIFICATION
c. Chases, slots, reglets or openings necessary for the proper installation of
work of other trades shall be formed as required. Keep chases and reglets
free from mortar or other debris.
3.04 WALL PLASTERING AND FLOOR TOPPING
a. Interior/Exterior plastering- 25 mm thk. Class A plastering, true to line prior to
wall finish. Excess from the 25mm thk. plastering shall be provided with ga. 18
1/2 x 1/2 wire mesh and shall be shouldered by the roughing contractor. This
applies to all areas on painted, wallpaper and gutter and exterior wall indicated
on painted finish.
Note: Add 1 bag of crackstop for every 1 bag of cement for plastering works.
b. Concrete Topping- 50mm thk. Class A topping. Excess of 3 thk topping shall
be provided with ga. 10- 10mm x 100mm welded wire mesh and shall be
shouldered by the roughing contractor.
3.05 POINTING AND CLEANING
a. Execute work in as clean a manner as possible, removing excess materials
and mortar droppings daily. Remove mortar dropping on connecting or
adjoining work before it has attained final set.
b. At completion of work, point holes in joints of exposed masonry surfaces by
completely filling with mortar. After pointing has hardened clean the masonry
surfaces.
c. Wet exposed brick surfaces and then clean with a solution of 10% by volume
of meiotic(Hydrochloric) acid. Apply with stiff fiber brushes leaving the
masonry clean, free of mortar and with tight mortar joints throughout. Keep
the acid solution from contact with adjacent surfaces. Immediately after
cleaning, thoroughly rinse the masonry surfaces with clean water.
d. Clean exposed concrete masonry units by the use of wire brushes or other
method that will produce a satisfactory surface.
e.
Remove and replace defective materials; correct defective workmanship;
leave all masonry clean.
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