Greg Labbe: quality control issues in housing construction


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Greg Labbe of BlueGreen consulting showcases many quality control issues with new housing construction. Presented to the Toronto Certified Sustainable Building Advisor Program

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Greg Labbe: quality control issues in housing construction

  1. 1. 12/04/20131Putting PerformanceInto PracticeApril 12, 2013Sustainable Building Advisor CourseEvergreen Brick Works, with Greg LabbéABOUTGreg is a principal atBlueGreen ConsultingGroup Inc., offering highperformance energyconsulting and professionalservices to architects andbuilders, specialising inbuilding shell optimisation,diagnostics, training andtesting.
  2. 2. 12/04/20132Agenda• Introduction• Quality Management on the job site• Who and what’s involved in:– Design phase– Construction phase• On-site Testing and Inspecting• Construction practices to avoid• Conclusion• QuestionsIntroductionBuilding a sustainable, highperformance home starts at the designphase and ends predictably with asuccessful blower door test.Let’s explore the steps in between tolearn more about what makes a highperformance, sustainably designedhome the best product on the market.
  3. 3. 12/04/20133IntroductionA sustainable home means newmaterials, methods techniques; are thetrades you hire up to the newchallenges? Do they know what to do?A high performance home means you’reraising the quality bar, always involvessetting a standard and measuring to it.Performance isn’t this obvious.Modeling optimises and testing proves it.
  4. 4. 12/04/20134Students at HumberCollege test theCentre for UrbanEcology (last week!).It was LEEDcertified, but neverair tightness tested.ICI vs ResidentialQuality Management• Learning to build sustainably meansgrowing pains, yet>• Contractors in the USA who switched tohigh performance building found theirbusiness grew as their peers businessescontinued to slide with the housing market.
  5. 5. 12/04/20135Quality Management• Quality is conformance to a written standard• Quality is measured by the cost of non-conformance• It is cheaper to do things right the first time• Most problems have roots in planning anddevelopment• Quality is shared by everyone from architect tobuilder to site supervisors and the trades.Philip Crosby, The Art of Making Quality CertainWhat do the following 3 slideshave in common?
  6. 6. 12/04/20136
  7. 7. 12/04/20137Any guesses?
  8. 8. 12/04/20138There’s a shortage of goodplanning, clear specificationsand an even greater shortage oftrades who have time to thinkthings through.Let’s review>How dowe getthe dooropen.
  9. 9. 12/04/20139A window wasadded afterthe wall wasbuilt. Note thebracing wascut…The tiles were removedbecause someone forgotthe floor heating element.
  10. 10. 12/04/201310What’s the Cost?• “Quality is free, but no one is ever going to knowit if there isn’t some sort of agreed-on system ofmeasurement.”• “The purpose of calculating the cost of quality isreally only to get management’s attention and toprovide a measurement base for seeing howquality improvement is doing.”Quality is Free• A quality program can save a company moremoney than it costs to implement• Profitability is best accomplished by reducing thecost of poor quality and preventing defects• Cost savings include prevention, appraisal, andfailure costs.Philip Crosby, The Art of Making Quality Certain
  11. 11. 12/04/201311Quality is a StandardPick a standard or rating system and follow it!Differentiating yourself in the market place.
  12. 12. 12/04/201312A note on Quality ProgramsTwo interesting articles on implementing qualityprograms on construction sites:1. Applying Lean Thinking to the Passive HouseProcess, David Hawkins & Russell Richman,Ryerson University.2. Achieving High Performance Homes ThroughQuality Management, Duncan Prahl, HomeEnergy Magazine, 2012Who’s involved in:Design phase• Once you’ve picked your standard, you’llhave to assemble your high-performanceteam:– 3rd party energy modeller with field experience– Architects that are familiar with performance– Builders that know their work will be tested– A mechanical designer who knows “microload” systems
  13. 13. 12/04/201313What’s involved in:Design phase• Specifications are decided on early as partof the IDP.• Super high efficiency houses differ in:– May not have “typical” heating systems– Are quiet, so mechanicals need to be too!– Allocation of budgets are different insustainable builds.What’s involved in:Design phase• Super high efficiency houses differ in:– Materials are different• VIG, Densepack cellulose• Double stud wall, VIP• Straw bale Rammed earth– Techniques are different to avoid thermalbridges with significantly different details..>so different skill set needed
  14. 14. 12/04/201314What’s involved in:Design phase• Last but not least, high performancestructures differ form ‘code built’ in:– You need the get the building inspector onside– Building Officials typically don’t like newthings, but if you show establish a relationshipearly, they will see the value.What’s involved in:Design phasePlan for and expect push back unless thecontractor is experienced in the techniques aswell as their sub-trades.If using a builder new to the techniques, bringthem in early to make them feel like they arepart of the decision making process.
  15. 15. 12/04/201315Design Phase: SimulationsLet’s look at the following, simplified example of awall section with a standard sized window in it.10’8’2’3’R2 R20Scenario 1: Consider a wall and a window…
  16. 16. 12/04/20131610’8’2’3’R2 R20What’s the R value of the entire wall assembly?10’8’2’3’R2 R20Entire wall assembly only R12*!*This calculation IGNORES the thermal bridgingat each stud, so it’s even worse!
  17. 17. 12/04/20131710’8’2’3’R2 R40Scenario 2: New wall and same window…Let’s spray foam the wall!10’8’2’3’R2 R40What’s the R value of the new wall assembly?
  18. 18. 12/04/20131810’8’2’3’R2 R40Composite R value: 16.5.The window is dragging the R valuedown; energy modeling identifiesthese issues.10’8’2’3’R8 R20Reconsider Scenario 1: with a better window…
  19. 19. 12/04/20131910’8’2’3’R8 R20Any guesses on the composite R value?10’8’2’3’R8 R20New composite R value R18
  20. 20. 12/04/201320Design Phase: SimulationsYou cannot break the 2nd Law of Thermodynamics:Heat goes from more to less.Heat will find a way through “cheap” bridgingelements or features dragging the overallperformance down.Luckily, good energy modeling can help you maketough choices!Design Phase: SimulationsHigh performance doesn’t just happen; it evolvesthrough an iterative process like the IntegratedDesign Process (IDP).This process is usually lead by a professionalintimately familiar with the standard you’ve chosen.
  21. 21. 12/04/201321Design Phase: IDP+SimulationsDesign Phase: IDPThe design team, homeowner and builder sitwith the energy simulator professional.Together, they go through an iterativeprocess of optimisation where performanceis optimised and building costs areminimised or as Paul Dawkins says“tunneling through the cost barrier.”
  22. 22. 12/04/201322Design Phase: IDPSource: CMHC, IDP GuideDesign Phase: IDPSource : Ann Edminster, GBA Advisor
  23. 23. 12/04/201323Design Phase: Optimised• Out of this IDP process, the final plans areissued and the specifications for thefollowing are set:– The R values and assembly details for thewhole building shell including the slab– The air leakage threshold– Exacting window specifications for eachfaçade.– A short list of mechanicalsDesign Phase: Optimised"We need to use integrated design processthat can create new approaches and tools,and beautiful environments that can restoresocial, economic, and environmental vitalityto our communities."— Bob Berkebile, BNIM, Kansas City, one ofthe world’s most respected green architects
  24. 24. 12/04/201324Design Phase: OptimisedFurther reading:– Integrated Design Process Guide, AlexZimmerman, CMHCWho and what’s involved in:The construction phase• All hands involved in the planning,directing, testing and assembly of thebuilding need to know the standard andhave clear written instructions.• They must be able to explain the goals ofstandard and must know why the standardis important.
  25. 25. 12/04/201325Who and what’s involved in:The construction phase• Starts in the design phase with theselection of the standard and the detailedspecifications for the assembly andmaterials to be used.• You must impress that quality will bemeasured both in the ‘cost of quality’, willbe visually inspected and air tightnesstested.On-Site Testing and InspectingIdentifying and respecting the air barrier.• Most standards have min. threshold of airleakage in order to be certified.• Everyone on the jobsite must be able to idthe air barrier, even at transitions.• All should be able to draw it’s placementon a cross section with a red pen.
  26. 26. 12/04/201326ID Air BarrierPolyethylene air barriersystem (very cold climatesonly—Zones 6 or higher)Source:www.buildingscience.comID Air BarrierHousewrap air
  27. 27. 12/04/201327ID Air BarrierExterior sheathing (insulated ornot) air barrier systemSource:www.buildingscience.comThis is a blower door.Love this guy/gal!S/he can help you find theleaks and be part of yourquality management team.They see lots of differentthings… and can be a sourceof great informationAir BarrierTesting
  28. 28. 12/04/201328Educate CrewsOften the best way to educate reluctant crews is tobreak the message down into it’s barest elements.>Like the following about ultra-efficient houses.
  29. 29. 12/04/201329
  30. 30. 12/04/201330Construction practices to avoid• The following slides are a collection ofcommon issues in contemporaryconstruction.• Most are dry walled over and will haunt thehomeowner.
  31. 31. 12/04/201331Notes on Spray foamFoam is combustible
  32. 32. 12/04/201332Check your foam for depth!W H E R E D I D T H E F O A M FA I L ?M a n y ‘ b l i s t e r s ’ ( p a i n t e d o r a n g e )w e r e f o u n d t h r o u g h o u t t h e ½p o u n d f o a m . W h e n p r e s u r i s e dt h e y l e a k e d a l o t o f a i r. F o a m w a su n a t t a c h e d o r d e l a m i n a t e d .
  33. 33. 12/04/201333WHEREDID THEFOAMFAIL?The blisterswere nearly14oC hotterthan thesurroundingfoam.Foam to poly>
  34. 34. 12/04/201334Brick ledges & Lintels WRT Sheathing
  35. 35. 12/04/201335The Pony wall: Diaper vs batt.
  36. 36. 12/04/201336Watch ThoseTransitions
  37. 37. 12/04/2013372LBS Spray foamCellulose InsulationSoffit ventFollow the airbarrierNotes on Steel• Steel has amazing strength, but not onlydoes it conduct heat amazingly well, it alsois really hard to detail insulation and airbarriers around it.• It has been known to cause condensationproblems and discomfort.
  38. 38. 12/04/201338Is itreallysealed?
  39. 39. 12/04/201339
  40. 40. 12/04/201340
  41. 41. 12/04/201341Beam pocket: How do you sealthe air barrier to the beam?Steeleverywhere!
  42. 42. 12/04/201342What steel looks like in Infrared.. in Unconditioned Spaces• Installing ductwork outside the envelope isnever a good design; avoid it.• We get called back to “improve” thesedesign flaws.
  43. 43. 12/04/201343More exposed supplyside leakage meanshot humid attic,depressed livingspace, constantlywashed with freshoutside dry BSD-102:Understanding AtticVentilationC O N D E N S AT I O N E V E R Y W H E R E !… f o r m i n g m i n i p o o l s o fc o n d e n s a t i o n o n t o p o fp o o r l y i n s u l a t e d E R Vi n l e t d u c t , s o m u c hs o t h a t i t ’ s d r i p p i n gd o w n . . .
  44. 44. 12/04/201344U N D E R T H E D U C T S TO O !The Bonus Room
  45. 45. 12/04/201345ExposedfloorDucts
  46. 46. 12/04/201346SkylightsThis was a 17’tall triangularshaft, with a20’x2’ opening inthe ceiling for a2’x4’ skylight.Condensationand uncalculatedheatloss.
  47. 47. 12/04/201347Top plate penetrations:The OK…Thebad
  48. 48. 12/04/201348TheuglyStairs vs Poly: who’s there first?
  49. 49. 12/04/201349Who’sthere first:Electricianorinsulator?Air tightness• Houses don’t need fresh air; occupantsdo.• Build tight; ventilate right.• Ventilation is not something you let thebuilding shell take care of through‘leakage’.• Ventilation is something that needs to becontrolled precisely and actively.
  50. 50. 12/04/201350Which envelope is more airtight?Ed Marion’s analogy…. www.passivehouseontario.caA tight envelope>1. More durable: Has less moisture pumpedthrough the envelope.2. Saves money: Less3. More comfortable: Keeps humidity andmore even temperature throughout.4. Less liability: We’ll show you pictures ofrecalls that dogged designers andcontractors.
  51. 51. 12/04/201351Zen master says>Moisture movement canonly be controlled bystopping air flow*.* And capillary action.Control moisture by>• Stop unwanted air flow and you stopmoisture from causing condensation thatleads to unhealthy mould and structuralrot.
  52. 52. 12/04/201352Good ventilation strategy?
  53. 53. 12/04/201353For optimum health a humanneeds:• Q: How many glasses of water per day?– A: 8 glasses per day• Q: How many m3 of fresh air per day?– A: 10m3 per day* or ASHRAE 62**recommends 611m3 per day.*Assumes 7.5litres per human/minute to deplete air from 21% O2 in to 16% O2out.** Based on 15CFM per person or min 0.35 ACH.Heat Recovery Ventilation
  54. 54. 12/04/201354Heat Recovery Ventilation• Often, lose and leaky buildings have HRVsin them and the intent for preciseventilation is lost at a huge energy penalty.• As the building shell gets more air tight,the value of having an HRV increases.Dedicatedreturns toHRV
  55. 55. 12/04/201355A 40’ductrun!!That’s better
  56. 56. 12/04/201356Columns
  57. 57. 12/04/201357Thebumpout fromoutside.The bump out from thebasement..
  58. 58. 12/04/201358The bump out from themain floor..The bump out from the2nd floor..
  59. 59. 12/04/201359AbovegradeBump-out
  60. 60. 12/04/201360
  61. 61. 12/04/201361• What it could have looked like.• Source:
  62. 62. 12/04/201362Thedoublewall
  63. 63. 12/04/201363Clamp thatpoly!(if it’s yourair barrier)
  64. 64. 12/04/201364Clampthat polyin thedropceilings.Badfoam/poly.Getting airbarriersealingaround allpenetrations
  65. 65. 12/04/201365DesignFlourishesthatsquanderBan faux chimneys
  66. 66. 12/04/201366Extrabedroom:gone!
  67. 67. 12/04/201367SillyRecom-mendations
  68. 68. 12/04/201368Conclusion• Do it once, do it right;• Select your team & standard carefully• Optimise your house by energy simulation• Get everyone on board early• Calculate mistake cost as a % of sales.• Test and inspect, especially with newplayers.
  69. 69. 12/04/201369QUESTIONS?Thanks for your timetoday.TAKING THE BLUES OUT OF BEING GREEN!