Monday, 30 June 2014

Construction Industry (Minimum Quality Standard)



QUALITY CHECKLIST

A checklist that has been invisible most of the time during construction process, mostly due to the tender habit that we adopted.
Below is the minimum standards  (unspoken) quality that I expected from my Contractor.

 

A.  REINFORCED CONCRETE WORK (PDI Stage 1) – 100% Inspection -

I

Formwork





1
Tolerance for  cross sectional dimensions of cast in place & pre-cast elements : +100mm/-5mm.





2
Tolerance for length of pre-cast members: 1mm/m to a maximum of 10mm





3
Penetration/opening for M&E services must be provided, tolerance for size: 10mm & location: 25mm.





4
Alignment, plumb & level:
1.     Tolerance for departure of any points from its position: 10mm
2.     Tolerance for plumb: 3mm/1m, max of 20mm
3.     Max deviation of mean level of staircase thread to temporary bench mark. + 5mm.
4.     For cast-in place elements, the deviation of level of any point from the intended level: +10mm.





5
Formwork must be free from loose knots, splits, cracks / other defects.





6
Before concreting, the interior must be free from design material such as rubbish, chippings & shavings





7
All formwork joints must be sufficiently tight to prevent leakage





8
Adequate support and bracing for the formwork.






II
Reinforcement




1
Main and secondary rebar  =  structural drawings (no., size, spacing) & approved by Architect





2
Anchorages & lap lengths = structural drawings





3
Cover provision = specification





4
Links, stirrups & trimming bars = structural drawings (no., size, spacing)





5
Ensure rain water down pipes are installed & protected







III
Finished Concrete / Ready Mixed Concrete




1
Tolerance for cross-functional dimensions of cast-in place & pre-cast elements: + 25mm





2
Opening must be provided. Tolerance for size: + 10mm, location:=25mm





3
Tolerance for length of pre-cast element <: 1mm/1m,max of 5mm





4
Tolerance in straightness of pre-cast members: for elements<5mm, max. +10mm;elements > 5m, max + 20mm.







 

B.  STRUCTURAL STEEL WORK

1
Sample approved by Architect / Engineer.





2
All test results meet contract spec. :
a.   Magnetic particle flaw detection test.





b.   Ultrasonic examination.





c.   Radiographic examination





d.   Bend test on shear studs.





e.   Others





3
Plumb & alignment :





a.   Plumb tolerance : 5mm / 10mm height, max. +15mm.





b.   Line &  level deviation : + 5mm





c.   Steel members free from twist unless curvilinear in form or 
      specified chamber





4
Cutting & dimensions :
a.   Cut edges visually dressed to finish & free from distortion.





b.   Length & hole tolerances are as specified.





5
Welding :
a.   Correct types & sizes of electrodes used as specified.





b.   Welds free from slags & other inclusions.





c.   All welders posses the required qualifications.





6
Bolting :
a.   Correct types & sizes of electrodes used as specified.





b.   Thresded bolts project through nuts as least 1 thread with
      washer.





c.   All bolt tightened to specified torque with torque wrench.





7
Corrosion & Fire Protection :
a.   Protection such as paint coatings & fire protection coating evenly applied & no damages to the coating, if requested in the contract spec.








C.   PRESSED CONCRETE ( PRE & POST TENSIONING FOR CAST-IN-PLACE & PRECAST WORK )
1
Condition of tendons & anchorages :
a.   All prestressing strands & wires = specified standards &
      requirements & be free from loose rust, oil, tar, paint & any
      foreign object.





b.  All tendon anchorages a = specified standards & protected
     from corrosion. Thread part to be greased wrapped & tapped
     holes protected until use.




2
Installation of sheathing :





a.   Sheathing properly secured & free from damage puncture





b.   Sheathing profile = drawing throughout the length with
      tolerance of position + 5mm.     





c.   Splice to sheathing shall be mortar tight.





d.   Air vents or grout tubas provided = drawings.





3
Stressing & grouting process :
a.   Tendon duets clean & free from foreign objects & tendon free
      moving in the duct.





b.   Strands stressed to the final pressure / elongation within the
      specific % of the stipulated value.





c.   All grouting operations of the tendons must be smooth &
      achieved without need to flush out in the first grouting.





4
Debinding (for post tensioning only) :
a.   Open ends of debond tubes over the debond length of strands
       sealed.





b.   Debond lengths = drawings.





c.   Debonding materials not puncured or damaged.





5
Alignment, Plumb & Level :
a.   Tolerance for departure of any point from its position: 10mm





b.   Columns / walls between floors : +10mm.





c.   Columns / wall for entire height: +40mm tolerance for size:
     10mm &  location:25mm





d.  Tolerance for plumb: 3mm/1m, max of 20mm





e.   Max. deviation of mean level of staircase thread to temporary
      bench  mark. + 5mm.





f.   For cast-in place elements, the deviation of level of any point
     from the intended level: +10mm.





6
Honeycomb-should not have visual expose of grouts of coarse aggregates resulting from grout leakage.






IV
Concreting




1
Concrete grade = contract spec’s BQ





2
Slump test = contract spec. (75mm+25mm)





3
Placement of concrete





a.   Fresh concrete after placement should be protected from rain.





b.   After concrete has hardened sufficiently, surface must be kept
       moist.




4
Curing – Exposed surface to be kept moist for 3 days min. or otherwise required by engineer.





5
Test cube for every pour of concrete at 7 & 28 days contract spec. (BS5328)





6
Striking of formwork & re-popping:





a.   Cube test > 10N/mm2/. 24 hours for verticals forms and . 72
      hours for  sort fits or otherwise stated in specifications.





b.   Elements re-popped after striking of formwork for specified in
      specification period.




























D.   ROOF (PDI stage 4)
I
Roof Truss – timber or steel




1
Pressure treated timber = contract spec. & approved by consultant





2
Test Certificate approved by consultant





3
Structure = drawing






II
Pitch Roof




1
Sample of roof tile = contract spec. & approved by Architect





2
Falls = contract spec. (+ 10%)





3
Sufficient lapping of roof tiles = contract spec. & firmly secured.





4
Depth of ponding < 3mm & inward corner > 95 degree





5
Flashing cover 2 complete troughs of tiles or 400mm length whichever is longer





6
Party to be plastered prior to capping.





7
Capping covers all projected party from one end of flashing to another end of flashing





8
No crack tiles.





9
Proper seal compound over nut & bolt






III
Aluminum Foil




1
Sample, shop drawing & manufacturer approved by Architect





2
Unless otherwise specified, all aluminum must be extruded, the extruded section shall be an approved Architectural aluminum alloy of either B6063 or KE-45 or its equivalent or its equivalent confirming to the requirements of BS1470-1475:1972. Thickness for Aluminum section> 1.2mm = contract spec. Hardness shall be T-5 conforming to BS1474. All joints in frames, corner junctions or intersection shall be electrically weided.











IV
Gutter




1
Appropriate fall = shop drawing.





2
No choking or depth of ponding < 3mm




3
Water proofing provided = contract spec. / shop drawing.





4
The upstream gutter sit on top of the downstream gutter with sufficient lapping.





5
No sign of leakage





6
Appropriate depth of valley taking into the consideration of roof






V
Rain Water Downpipe




1
The diameter 4” or preferable 6”





2
Sufficient length to channel water toward the grout level drain





3
No choking & sign of leakage






VI
Flat Roof – Water Proofing




1
Hitchins Traffiguard – Water proofing system = contract spec or manufacturer’s instruction:





1.   A layer of 1:4 with 25mm thickness of base screed laid to falls
      &  crossfalls.





2.   Primer – fills hairline & minor cracks.





3.   Body coat – acrylic polymer gel for strengthening the system.





4.   Fibre glass mat-glass fibres to reinforce the resistance to wear
      & tear.





5.   Second body coat – added protection & an attractive surface
      finish.





2
Concrete roof slab screeded to fall finished smooth.





3
Dilute Traffiguard with water (4:1) & apply primer coat at coverage of 9m 2/I. Allow to dry.





4
Apply one bodycoat over primer at a coverage of 2.5m2/I & while it is wet, unroll fiberglass mate over it.





5
Immediately apply a second bodycoat over fiberglass mat at a coverage of 2.5m/I ensuring that the fibreglass mat is fully immersed with Traffiguard gel. Leave till dry.





6
Apply top coat at a coverage of 1.5m 2/I.





7
Water proofing materials should be evenly installed with complete adhesion to base, good laps at joints & proper vertical lapping, no sign of damage & leakage.





8
Warranty of 10 years guarantee against any failure or leakages due to workmanship or materials = contract spec.










E.   DOOR FRAME, WINDOW FRAME, BRICKWALL (PDI stage 2)
I
Door Frame





1
Door frame = contract spec.





2
Plumbness & alignment of door frame





3
Lintel Quality and its anchorage ( check present of fishtail)





4
Distance between door frame &  wall should be sufficient to allow full architrave






II
Window Frame




1
Window Frame = contract spec / drawing.





2
Plumbness & alignment of window frame





3
Lintel quality and its anchorage ( check present of fishtail ).





4
Protection of window frame






III
Brickwall




1
Sample approved by





2
Brick/block’s dimension, shape = sample





3
No crack, chipped on brick / block.





4
Dowel bars are installed at R.C. wall / column face adjoining brickwall. Stiffeners should be grout in-fill & installed = drawings.





5
Bricks are thoroughly wet before laying = contract spec.





6
Bricks clean from grease / dirt before laying.





7
Position of Block wall = contract spec.





8
The last layer of brick should be laid diagonally & infill mortar.





9
Ex-mat to be installed at certain layer of brickwall = contract spec.





10
Damp proof course installed = contract spec.





11
Verticality of brickwall, tolerance < 4mm / 1.2m.





12
Setting out / dimension = SPA





13
Any changes in aesthetic.








F.   PLUMBING (PDI Stage 3)
I
Water Tank, Cold & Hot Water Supply System





1
Materials & shop drawing approved by Consultant.





2
Water storage tanks, water elevating pump, water booster pumpsets, hot water circulation pumps, hot water supply system = contract spec. & shop drawings.





3
Minimum distance between hot water copper pipe & cold water pipe = 6”





4
Ball valve = contract spec. Check functioning by filling the tank full with water.





5
Pipe printed with MS/BS standard code = contract spec.









II
Floor Traps & Gully




1
No choking & damage





2
Securely fixed





3
Trap’s top ½” lower than the surrounding floor level.






III
Piping




1
Materials = contract spec





2
Visually aligned horizontally, vertically & parallel with building surface. Inclined pipes laid to proper gradients.





3
Stop cork to be installed underneath.





4
Proper anchoring of pipes ( no burning allowed ).





5
No leakage at joints.





6
Brackets are firmly secured & adequately spaced.





7
If painted, no drippings & good opacity.





8
Pressure test for all water pipings meets contract spec.






IV
Fittings




1
All fittings = contract spec. & approved by Architect.





2
Firmly secured





3
No leakage at joints.





4
No chipping or cracks





5
Free from paint drops or mortar dropping.







G.   ELECTRICAL AND TELEPHONE (PDI stage 3)
I
Cable conduits, Trays, Trunking And Ducts





1
Conduit = contract spec.





2
Cable Trays = contract spec. for main cable. Submain cable etc.





3
Sample for plug / switches / socket approved by consultant.





4
Quantity and position of plug switches / socket = drawing





5
Quantity and position of ceiling-light, wall light and fan points.





6
Quantity and position of air-cond points.





7
Quantity position of TV points.





8
Quantity and position of gate points.





9
Quantity and position of door bell, sensor, power supply for automatic gate.





10
Wire run vertically & horizontally, wire run diagonally is prohibited.





11
Each plug / switches / socket must connect directly to main DB in one-to one basis.





12
Metal Trunking – fabricated from mild steel sheet & = contract spec





13
Colour coding = contract spec.





14
Test and commissing.






II
Telephone Service




1
Quantity and position of telephone outlet = drawing.





2
Position of DP box = drawing.





3
Manholes = contract spec.










H.   PLASTERING (PDI Stage 5)

I

General





1
Plastering should be prepared at least 3 days after the completion on brickwall = contract spec.





2
The surface shall be cleaned & wetted before plastering = contract spec.





3
Plastering mix – 1 part of cement to 6 parts of sand = contract spec.





4
Alignments seat on brickwall surface before commencement of plastering work.






5
1st coat of 10mm thickness applied to the area having greater deviation from the intended finish surface.





6
2nd coat of 10mm thickness applied over the whole area to finish the plane & shape.





7
Straightness of corners.





8
At the interface between R.C. structures & brickworks, reinforcement in the form of exmet or Hib-rib shall be provided to prevent cracking due to differential shrinkage.





9
No patches due to patching work.





10
No hollowness between coats of plaster.






II
Internal Walls




1
No cracks along wall.





2
Steel trowel spreading plaster evenly-gap between 1.2m long ruler and surface < 4mm (4mm/1.2m).






III

External Walls





1
Wood float spreading plaster to ensure surfaces visually even.






I.   FLOOR (PDI Stage 6)
I
Water proffing in Bathroom





1
‘Hitchin Vandex & Vandex premix cementations’ = contract spec.





2
Vandex super at 1kg/m2 applied in one slurry coat to hardened, clean concrete surface by means of masonry brush or DRY sprinkle & tavel – applied to fresh concrete when it has reached initial set. Where 2 layers of Vandex are demand the second layer must be applied when the first layer is still green but sufficiently set, so that it is not drawn off when applying the second coat.




3
Warranty of 10 years guarantee against any failure or leakages due to workmanship or materials.






II
Screeding




1
Cement & sand mixed ratio : 1 part of cement with 3 parts of sand = contract spec.





2
Screeding thickness for various floor finishes >13mm & according to contract spec.:





1.   ceramic tiles – 40mm ( wood trowel )





2.   homogeneous tiles – 40mm ( wood trowel )





3.   marble tiles – 40mm ( wood trowel )





4.   quarry tiles – 40mm ( wood trowel )





5.   vinyl tiles – 40mm ( steel trowel )





6.   carpet – 40mm ( steel trowel )





7.   base to water proffing system – 20mm ( wood trowel )





8.   paving – 18mm ( steel trowel )





3
Ensure concrete surface clean & free from dust & dirt before applying cement slurry.





4
Cover screed with polythene sheet at least 3 days after laying = contract spec.








III
Screed Finish Floors




1
Depth of ponding < 3mm.





2
Width of cracks < 0.5mm.





3
No hollowness – tapping hard object on the floor.





4
Falls in wet areas such as kitchen and toilet should be in the correct direction towards floor traps or discharge points.





5
Extension joints should be provided at internal stated by architect.





6
For staircases, the variance in lengths of threads of risers 5 mm, noses must be straight.









J.   DOORS (PDI Stage 7)
1
Sample / shop drawing approval by consultant.





2
Straight alignment with wall.





3
No visible gaps between door frame & wall.





4
Fire stop provided when necessary.





5
Properly sanded down & good paint work.





6
Gap between door leaf & frame < 5mm.





7
No sags and warps on door leaf.





8
Ease in opening and closing.





9
Lock-set with good-fit & no stains.





10
Metal door frame no dented.





11
Glazing clean & evenly sealed with gasket.





12
Fixing screws, nuts, boilts, riverts, hinges & other fastening devices shallbe aluminum, stainless steel or cadmium-plated to the Architect’s approval. Allfixing anchors, brackets, attachments used in the erection of doors shall be stainless steel, galvanized steel or zinc or zinc-coated steel.






















K.   WINDOWS

1
Sample / shop drawing approval by consultant.





2
Straight alignment with walls.





3
No visible gaps between door frame & wall.





4
No rainwater leakage.





5
Proper installation with gap between window leaf & frame < 5mm.





6
Ease in opening and closing.





7
No mortar dropping & paint drips on frame and glazing.





8
Properly sealed with sufficient length of gasket.





9
Louvre window with glass panel to corrects lengths.





10
For ALUMINUM window:





1.   Type of fasteners used i.e. straps anchor bolts, brackets,
       lugs etc + drawing & spec.





2.   Aluminum members wrapped with tapes to prevent 
       scratches, cement mortar & paint splashes & dampness.





3.   Glazing clean, evenly sealed with gasket.






L.   GLASS

1
Manufacturer = BS950 & approved by Architect.





2
Free from cracks, bubbles, waves, scratches or other defects.





3
Exposed edges shall be rubbed down with corborundum stone and finished smooth = contract spec.





4
Type of glasses ( contract spec & drawing ) :





1.   Clean sheet glass : ordinary glazing – weight & thickness =
       contract spec.





2.   Obscure glass : plain rolled, sand blasted & to be cut &
      glazed so that the direction & face of the pattern is the same
      throughout ( for all windows & fixed glass panels for
      bathroom, W.C & internal door opening.





3.   Wired glass : shall be Georgian Wired glass & to be ‘line up’
      where required. Cut in such the wires in adjacent panes line
      up horizontally & vertically.





4.   Tinted glass : shall be float glass with thickness & colour to
       be tinted = contract spec. or Architect’s detail drawing.





5
Mirror = contract spec. – polished plate. Approved glass & fixed with chromium – plate dome – headed screw.





6
Putty = contract spec.





1.   Putty for glazing in wood sashes – approved tropical putty
      ( BS 544).





2.   Putty for glazing to metal – approved patent mastic.





Glass must be well bedded & back puttied.





All putty or mastic are carefully trimmed or cleaned off & not appear above the sight lines.





7
Rebates = contract spec :





1.   All timber rebates cleaned prime & printed with 1 coat of pain
      before glazing.





2.   Metal rebates cleaned & primed before glazing.







M.   TILING WORKS (PDI stage 6)
I
General




1
Sample approved by architect.





2
Tiles size are consistent ( within +1 %)





3
Thickness of bonding mortar sufficient = contract spec.





4
Joints are aligned & consistent with skirting & wall tiles.





5
No chippings, cracks or mortar droppings.





6
No hollowness – tapping hard object on the floor.






II
Floor Tiles




1
Evenness of tiles, tolerance < 4mm / 1.2m.





2
Falls in wet areas like kitchen & toilet toward floor traps or discharge points = detail drawing ( tolerance + 3mm ).





3
Tiles joints aligned & width 3-6mm unless otherwise specified in detail drawing.





4
Tiles joints applied with original cement.







III
Wall Tiles




1
Vertical alignment for wall tiles = contract spec. ( within 3mm ).





2
Tiles joints aligned &, 3 mm wide unless otherwise specified in detail drawings. ( tolerance + 3mm ).





3
Plumb tolerance < 3 mm / 1.2m.





4
Evenness of surface tolerance, 4mm / 1.2m.





5
Tiles joints applied with white cement or  = contract spec.





6
Edges should not exposed or otherwise at least finished smooth.






IV
Timber Strips




1
No nodes for the timber used.





2
Timber strips to rest firmly on joints or screed-no hollowness by tapping hard object on the floor.





3
No gaps in between timber strips.





4
Edges of the floor to be properly sealed.







N.   CEILING (PDI stage 7)

I

False Ceiling




1
Alignment of rails should be visually straight.





2
Sufficient hangers & clips.





3
Surface should be overall level & even.

















O.   SKIM COATS

1
Gap between light fittings & ceiling < 3mm
.




2
Surface over even.





3
No leaks, stains or spilling.





4
Paintwork with good opacity.





 

 

P.   PAINTING

1
Colour code = specification & approved by Architect





2
Surface evenly painted, no patchiness to touch up work.





3
Good opacity, no discolouring, free from peeling & no paint drips.





4
Warranty certificate from manufacturer.







Q.   CLADDING
1
Proper anchorages for panels.





2
Joints of regular widths = contract spec.





3
Plum tolerance < 3mm / 1.2m.



















R.   ARCHITECTURAL COATING

1
Sample = contract spec. & approved by Architect.





2
Colour Uniform.





3
Free from paint drips & other stains.





4
Paintwork with good opacity.





S.   APRONS

1
Bitumen joints with neat edges.





2
No mortar dropping.





3
Crack, width < 1mm, length < 0.5m.





4
No ponding.

















T.   DRAINS

1
Sufficient internal drainage channel = drawing.





2
No ponding of water – appropriate fall





3
No choking & free flowing.





4
No mortar dropping.





5
Concrete slabs over drains properly secured.


















 

U.   SOIL LEVEL AT GARDEN  

1
Fall to drainage

















V.   GATE AND OTHERS  
1
Types of gate & gate leaf = drawing & approved by architect.





2
Rubbish compartment = spec.





3
Post box = spec





4
Type of fencing = drawing.















1 comment:

  1. Quality Checklist is what we have ignored, there is a good explanation, or,simply because, Architect also ignore them!...

    ReplyDelete