This presentation is on the importance of ensuring the quality in construction.

1. AIM FOR QUALITY IN CONSTRUCTION
• TRAIN YOURSELF TO BE QUALITY CONSCIOUS!
• WHAT QUALITIES & ABILITIES MUST YOU
CULTIVATE TO BE QUALITY CONSCIOUS?
• HOW CAN YOU ENSURE THE QUALITY OF
BUILDINGS YOU SUPERVISE?

2. 1. Be observant regarding:
* Quality of materials
* Quality of workmanship
* Quality from foundation to finishes
2. Be capable of convincing masons,
carpenters, beneficiaries of reasons to
maintain quality standards
3. Be informed about:
Quality construction standards & specific
technical requirements for the project.
4. Be concerned about: implementing quality
standards in construction

3. FUNDAMENTALS OF STURDY, SUSTAINABLE
CONSTRUCTION
• ALL COMPONENTS MUST BE WELL INTEGRATED
TO WITHSTAND EXTERNAL FORCES
• ALL LOADS MUST BE TRANSFERRED DIRECTLY
DOWNWARDS
• ALL CONSTRUCTION METHODS MUST CONFORM
TO THE HIGHEST STANDARDS OF QUALITY
• DESIGN AND CONSTRUCTION MUST ENSURE THAT
WATER/DAMPNESS DOES NOT ENTER THE
BUILDING FROM ABOVE, SIDES, AND UNDER.
• ALL COMPONENTS MUST SATISFACTORILY
WITHSTAND THE HARMFUL EFFECTS OF SUN,
WIND, RAIN, AND FLOOD.

4. CHECK QUALITY OF BASIC MATERIALS
Foundation Stone – Size, hardness
Bricks and blocks – Size and strength
Sand – Free of excessive clay and impurities
Metal (aggregate) – Consistency of size
Timber – Quality and sizing
Roofing tiles/sheets – Quality consistency

5. CHECK FOUNDATION TO FINISHES
• Foundation
• Plinth beam & DPC
• Compacted earth fill & DPM
• Superstructure
• Roof
• Doors and windows
• Wall and floor renderings
• Wall finishes

6. REJECT POOR QUALITY BLOCKS/BRICKS
• To check use drop test, scratch surface for
quality, tap bricks together for ringing sound.

7. ENSURE THST MASONRY BLOCKS/BRICKS
ARE OF GOOD QUALITY
Good quality masonry
blocks and bricks:
•Have clean sharp edges
•Have hard surfaces that do
not crumble when scraped
•Will not break when
dropped from 3 ft. Height.
•Have non-porous quality
Always soak blocks or
bricks before placement.

8. REJECT SAND WITH & EXCESSIVE
CLAY/IMPURITIES (left side of picture)

9. CHECK ON-SITE FOR SAND QUALITY

10. ENSURE THAT QUALITY CEMENT AND
REIFORCEMENT STEEL ARE USED
• Cement must be of powdery texture. Reject
cement that is gritty or contains hard lumps.
• Cement must be stored in a sheltered, dry
location, and used without delay.
• Reinforcement steel must be relatively free of
dirt & rust. Where rust is present, remove rust by
brushing with a wire brush. Where oil is present,
it must be wiped off or burned away thoroughly
before using.

11. REJECT WARPED, SPLIT, DECAYED, TIMBER
WITH EXCESSIVE KNOTS & PITH

12. REJECT POOR QUALITY TILES THAT ARE
CRACKED, DEFORMED, OR CHIPPED

13. SITE CLEARING/PREPARING CHECK
• Uproot trees, remove vegetation at
building footprint. Remove top soil when
excavating foundation trenches and store
safely for re-use.
• Ensure that water does not stagnate on
site near building operations.
• Determine locations for material storage,
concrete mixing, bar bending, work bench,
etc.

14. CHECK SOIL TYPE TO KNOW IF PLINTH
BEAM IS NEEDED. SOIL ON RIGHT SIDE
IS CLAYEY; NEEDING PLINTH BEAM

15. CHECK WATER TABLE LEVEL AT SITE
HOW CAN THE WATER
TABLE BE CHECKED?
– Check the level of
water in the well on-site,
or check water
level in the closest
well.
– Find out from local
residents the known
high water level during
past rainy seasons.
WHY CHECK WATER
TABLE LEVEL (WTL)?
•The WTL needs to be
known to design suitable
foundation
•The high water table level
must be known to determine
the placement of the septic
tank, and the height of the
toilet floor.

16. SETTING OUT CHECK
• Centre lines of walls must correspond with
dimensions in working drawings.
• Use 3-4-5 method to establish 90 degree
corners, and verify with diagonal check.
• Check distances to all boundaries.
• Technical officers must personally check &
approve all setting-out lines before foundation
trenches are cut. Allow for working space in
trenches.

17. CHECK CORNERS AND SQUARENESS OF
ROOMS AND BUILDINGS

18. FOLLOW STEPS IN SETTING OUT
ACCURATELY

19. CHECK FOUNDATION DEPTH with drawings &
BLINDING SCREED (3” thick, 1: 3: 6 (1 ½”) mix)
@ FOUNDATIONS (min: w=18”, d=18”)

20. MORTAR & CONCRETE: FIRST - THOROUGH
DRY MIX. NEXT - THOROUGH WET MIX,
WITHOUT EXCESSIVE WATER

21. USE SLUMP TEST WITH EVERY BATCH OF MIXED
CONCRETE

22. DO NOT ALLOW FOUNDATION STONES TO BE
PLACED DIRECTLY ON SOIL WITHOUT
SCREED CONCRETE AT THE BASE

23. INSIST ON PROPER SCREED CONCRETE
TAMPING METHOD WITH TAMPING DEVICE AS
SHOWN ON RIGHT

24. CONCRETE, SCREED & MORTAR MIXES
• Concrete for foundation and superstructure columns,
beams, lintels, floors, staircases, and lintels – 1 : 2: 4
(3/4”) cement; sand; metal
• Blinding screed under foundation of walls and columns –
3” thick, 1: 3 : 6 cement : sand: metal (1 ½”)
MORTAR & RENDERING
• Mortar in foundation random rubble to DPC – 1:6 cement
: sand
• Mortar in s/s Conc. Block masonry – 1:5 cement : sand
• Mortar in s/s 9” brick Brick masonry – 1:8 cement : sand
• Floor cement rendering – 5/8” 1:3 cement : sand
• Skirting & Plinth ct. rendering – ¾” 1:3 cement : sand

25. IN FOUNDATIONS, USE LARGER STONES
MOSTLY (picture @ left); DO NOT USE MANY
SMALL STONES WITH EXCESS MORTAR
(picture @ right and sketch in next slide)

26. IN FOUNDATIONS USE THROUGH STONES, AND
DOWEL STONES AT CORNERS & JUNCTIONS

27. FOUNDATION/SUPERSTRUCTURE FAULTS
• Faults in foundation
can cause cracks in
superstructure walls,
rectification is difficult
and expensive. Be
sure foundations are
built properly.

28. DO NOT PLACE MORTAR ON UNFINISHED
MASONRY (as in this picture)
To ensure good bonding
between lower and upper
layers:
Remove all previously laid
hardened mortar from top of
foundation walls before
placing upper layers.
Place vertical dowel stones
at regular intervals to bond
with upper layers.

29. REMOVE RESIDUE MORTAR BEFORE CASTING
PLINTH BEAM, REJECT INCORRECTLY LINKED,
CONNECTED & LAPPED REINFORECEMENTS

30. REINFORCEMENT LAPPING & CONCRETE
COVER FOR REINFORCEMENTS
• Vertical reinforcement
lap length 30 x bar
diameter
• Horizontal
reinforcement lap
length 50 x bar
diameter
Note: Follow engineer’s
specifications if
different to above
standards.
Ensure the following
minimum thickness of
concrete cover to
reinforcements
•Foundations – 2” to 3”
•Columns – 1 ½”
•Beams – 1 1/2”
•Slabs/stairs – 1 1/2”
Note: Cover thickness to be
increased near coastal
areas due to salt content

31. REINFORCEMENTS BASICS

32. ENSURE Damp Proof Course IS PROVIDED &
Damp Proof Membrane PLACED PROPERLY
• DPC laid not less than
12” above ground level.
Lay 1/½” 20mm) layer
cement/sand (1: 3)
concrete; 3 coats tar.
Sprinkle with dry sand
• DPM (if used) to be
placed on bed of sand on
surface of dampened &
compacted earth fill. Use
1000 gauge polythene
film, lapped 6”@ joints &
sealed by taping.

33. DRY EARTH FILL MUST BE FREE OF
VEGETABLE MATTER, WELL COMPACTED IN
LAYERS AND DAMPENED (picture @ left)
Above picture shows
failure to remove all
vegetable matter in earth
fill at plinth.

34. WALLS TO BE VERTICAL WITH VERTICAL
JOINTS PROPERLY STAGGERED

35. MASONRY FOR SUPERSTRUCTURE
• For 6” (external load
bearing) & 4” (internal
non load bearing)
concrete block walls,
use solid blocks. Do not
use hollow concrete
blocks.
• Provide a continuous
RCC lintel at 7’ height
with vertical rfmts. at
corners/junctions to
above wall plate level.
Reinforcement bars to
wrap round wall plate.
• For 9” & 4 ½” thick brick
walls, provide a
continuous RCC lintel at
7’ height with vertical
reinforcements at corners
to wall plate level.
Reinforcement bars to
wrap round wall plate.

36. CLOSELY MONITOR QUALITY OF MASONRY
WORK AND RECTIFY FAULTS
• Too much mortar has
been used here, and
improper sized bricks
in this masonry work.
Use uniform full, half,
¼ & ¾ size bricks
• Masonry mortar must
be of uniform
thickness not greater
than 5/8”.

37. WALLS AT JOINTS AND CORNERS MUST BE
PROPERLY KEYED FOR CONNECTIVITY

38. PLACE INERSECTING WALL TO ENUSRE
THEY BOND WITH EACH OTHER

39. POSITION DOOR OPENINGS CORRECTLY
Above picture shows failure
to provide masonry nib at
the corner of the wall for
placement of door.

40. ENSURE THAT ADJOINING WALLS ARE
KEYED IN TO AVOID CRACKS DEVELOPING
• Failure to key-in
adjoining walls can
cause cracks at
joints in
superstructure
walls

41. POSITION EXTERNAL DOOR & WINDOW
OPENINGS SAFELY

42. CHECK SIZE AND PLACEMENT OF EXTERNAL
DOOR AND WINDOW OPENINGS; RECTIFY
IMMEDIATELY WHERE NECESSARY

43. ENSURE PROPER CASTING OF CONTINUOUS
RCC LINTEL (picture @ left). REJECT
INDIVIDUAL LINTEL CASTING (picture @ right).

44. ENSURE THAT CORNER REINFORCEMENTS
ARE PLACED AT CONTINUOUS LINTELS

45. PROVIDE CENTRAL RCC STIFFENER AT
GABLE WALLS FOR TILED ROOFS
• Load bearing gable
walls of 4” and 6”
thickness require a
vertical RCC
stiffener because of
the increased
height of the apex
of tiled roofs.
• Failure to provide
stiffeners can
weaken flexural
strength of walls.

46. BE ALERT TO NON PROVISION OF CORNER
REINFORCEMENTS & FAILURE TO WRAP
REINFORCEMENTS OVER WALL PLATE

47. REINFORCEMENT AT CORNERS VITAL
• Clearly explain to
masons, carpenters
& beneficiaries why
vertical
reinforcements
must be used at key
corners of the
building
• Ensure that the bars
are wrapped round
wall plates

48. CHECK QUALITY OF DOOR & WINDOW
FRAMES

49. PLACEMENT OF DOORS & WINDOWS: GOOD
PRACTICE

50. USE ONLY PROPER HOLDFASTS (Not nails)
FOR DOOR & WINDOW FRAMES

51. ENSURE THAT ADEQUATE NUMBER OF
HOLDFASTS ARE USED
• Holdfasts for
doors: 3 pairs
• Holdfasts for
windows: 2 pairs
• Failure to fix
holdfasts can result
in plaster around
frames being
dislodged as shown
in this picture

52. BE ALERT TO HEAD FRAME OF DOORS NOT
PLACED AT LINTEL SOFFIT HEIGHT

53. ROOF SLOPES MUST MATCH ROOF TYPES
• Minimum pitch of 25
degees for tiled roof
may be allowed in
areas with no high
winds.
• Surface rendering on
RCC flat roofs to be
sloped to allow ready
run-off of rain water
and prevent ponding of
water on roof surface.

54. PAINT PRESERVATIVE ON ALL ROOF
TIMBERS BEFORE PLACEMENT

55. PLACE WALL PLATES FLAT, NOT ON EDGE,
CENTRALLY ON WALLS (Supported at cantilever)

56. NOTE UNPAINTED ROOF MEMBERS AFTER
PLACEMENT & CUTTING, AND ENSURE THEY
ARE PAINTED

57. IMPROPERLY PLACED ROOF TRUSSES ARE
LIABILITIES WHEN PLACED ABOVE
OPENINGS IN WALLS

58. ALWAYS PROVIDE CONCRETE OR TIMBER
BASE PAD AT WALLS TO SUPPORT LOAD-BEARING
ROOF TIMBERS TO SPREAD LOAD

59. FAULTY ROOF SUPPORT TIMBER
FRAMING

60. THESE WALL PLATES FAIL TO SIT EVENLY
ALONG FULL LENGTH OF SUPPORTING
WALLS. ENSURE PROPER PLACEMENT.

61. SINGLE END-BATTEN ON EDGE UNSTABLE &
IMPROPER; ALWAYS FIX DOUBLE BATTENS

62. EXTENSIONS TO RAFTERS MUST BE OF THE
SAME SIZE AS RAFTERS (LHS picture); NOT
SMALLER IN SIZE (RHS picture)

63. BE ALERT TO IMPROPER PLACEMENT
OF ROOF TILES AND RECTIFY
• EACH SUCCESSIVE
ROW MUST BE
STAGGERED. TOP
PICTURE SHOWS
FAILURE TO DO SO.
• CHECK TILES FROM
INSIDE BUILDING TO
IDENTIFY FAULTS IN
TILE PLACEMENT OR
QUALITY (Picture below).

64. INSUFFICIENT CONCRETE BANDS @ ROOF

65. EXPOSED BATTEN ENDS WILL DECAY, IF NOT
COVERED BY BARGE BOARD

66. CORRUGATED ROOFING SHEET FIXING &
PURLIN/RAFTER FIXING IN HIGH WIND AREAS
• “j” bolts may be used in areas with no high winds

67. FRAMING FOR CORRUGATED ROOFING IN
HIGH WIND AREAS
• Provide diagonal bracing
at underside of rafters at
gable ends of roof
• Ensure that all rafters are
firmly linked to wall
plates, and rafters to
purlins (see anchor points
in figure)

68. ROOF EAVES IN HIGH WIND AREAS
• Eaves overhang
not more than
2’- 0”
• To deflect wind,
flat eaves soffit is
better than soffit
at rake

69. FLOORING: ENSURE RENDERING MIX IS
PROPERLY TAMPED. CHECK FOR CRACKS.

70. PROPERLY SLOPE ALL FLOORS TO PERMIT
EFFECTIVE DRAINING OF WASH WATER
• Ensure that
toilet floors are
properly sloped
to allow surface
water to be
readily drained
into outlet
drain. Instruct
masons
accordinlgy.

71. CEMENT PLASTER RENDERING ON WALLS
• External: 5/8”
(20mm) thick
rough plaster in
1:1:4 cement :
sand : lime.
• Internal: 5/8”
(15mm) thick
smooth plaster in
1:1:5 cement :
sand : lime.

72. GIVE ATTENTION TO PROPER PAINTING
STANDARDS
• Ensure plaster
surfaces are smooth
(rectify with filler),
clean & dry, then
apply paint undercoat
and overcoats as per
specifications
of manufacturer.

73. PAINT FINISHES
• For blistering, flaking,
peeling and cracking;
identify & eliminate
source/s of dampness.
Remove loose paint,
ensure surface is free of
grease, and allow to dry.
Apply primer coat and
repaint following
manufacturer’s
instructions.

74. IN KITCHEN/PANTRY KEEP WINDOW SILL
HEIGHT ABOUT 6” ABOVE WORKTOP
Above picture shows raised
sill height to reduce
damaging effect of water
form worktop on window
frame.

75. CHECK HINGE FIXING OF DOORS & WINDOWS
• Make sure that
adequate number of
hinges are used for
windows & doors
• Make sure that all
screws are provided
in all hinges
• Test if doors &
windows open &
close smoothly

76. RECTIFY IDENTIFIED BUILDING
DEFECTS
• SPECIFY CORRECTIVE ACTION TO RECTIFY
DEFECTS THAT ARE NOTED
• STRESS IMPORTANCE OF USING QUALITY
MATERIALS AND WORKMANSHIP
• STRESS IMPORTANCE OF SAFETY AND
SUSTAINABILITY OF BUILDING & ALL ITS
COMPONENTS
• RE-CHECK AFTER RECTIFICATION