www.fpinnovations.ca                       Design and Treatment                       Specifications for Durable          ...
Durability Concerns for Disaster Relief Housing• Need to maximize number of shelters pushes  down cost which leads to simp...
Durability Concerns for Disaster Relief HousingIn tropical/subtropical countries• High humidity and rainfall promotes deca...
Understanding the Decay and Termite Hazard• Scheffer index values indicate decay potential  – Derived from equation using ...
Native termites in Haiti• Subterranean termites    Reticulitermes sp.• Drywood termites         Cryptotermes sp.• Tree-dwe...
Coptotermes formosanus is the world’s mosteconomically important termite pest
Potential Transport of Coptotermes to Haiti etc.• Termites can be transported via trade or aid.                       Dryw...
Native termites in Indonesia• Copotermes gestroi mainly in cities  – C. formosanus sophisticated cousin• Coptotermes curvi...
Moisture Management      Design Solutions for DurabilityMoisture ManagementThe 4Ds   • Deflection        – Divert water   ...
Moisture Management      Design Solutions for DurabilityMoisture ManagementVapour Control inNorthern Climates             ...
Moisture Management      Design Solutions for DurabilityMoisture ManagementVapour Control inTropical Climates             ...
Design Solutions for Durability•   Pitched roof with overhangs on all sides•   Minimize penetrations in roof•   Minimize r...
Design Solutions for Durability• Support posts above concrete  – Prevent wicking of water  – Facilitate inspection for ter...
Integrated Termites Management : The 6Ss                     Developed Countries            SuppressionSurveillance       ...
Integrated Termites Management : The 3Ss             Disaster Relief                                 Structural           ...
Integrated Termites Management : The 3Ss                                                        Drywood                   ...
Integrated Termite ManagementStructure Durability• Most of our species are not termite resistant• Exceptions:  – Western r...
Preservative Treatment OptionsNot only the lumber needs to be treated• Plywood and PSL can be pressure treated• OSB can be...
Preservative Treatment OptionsMust consider• Regulations in exporting country• Regulations in importing country• Potential...
Preservative Treatment Options• Many countries have their own standards  – Former British colonies may use British (Europe...
Preservative Treatment Options• Canadian species mostly impermeable heartwood• Tough to meet foreign treatment standards• ...
Preservative Treatment Options• ACQ and CA Pressure Treatment  – Require incising (perforation) - 25% strength loss  – Rea...
Preservative Treatment Options• ACQ  – Copper ethanolamine – algaecide for pools and hot tubs  – Quaternary ammonium – dis...
Preservative Treatment OptionsACQ and CA pressure treatment• Choice of species is critical        High-density Incised Whi...
Preservative Treatment OptionsTermites eat through a thin shell of treatment
Preservative Treatment OptionsTermites give up if treated shell is thick enough
Preservative Treatment OptionsOr, if they get through, the box is strong enough
Preservative Treatment Options  • That is why I favour borate treatment  • Borates penetrate our woodRed colour with reage...
Preservative Treatment Options                         Borates have a                         positive perception         ...
Preservative Treatment OptionsAbove ground protected termite test                     400mm            1000mm             ...
Preservative Treatment OptionsPerformance of treated samples in Hawaii                      10                       9    ...
Preservative Treatment Options• In Hawaii almost all wood-frame homes are  100% borate treated.• Higher loadings required ...
Preservative Treatment OptionsNew surface-applied penetrating process• Developed for New Zealand market• Penetrating formu...
Preservative Treatment Options  New surface-applied penetrating process             Treatment results on BC SPF (pine)Red ...
Preservative Treatment OptionsNew surface-applied penetrating process   Treatment               Rating (10-0) at 2 yrs   C...
Preservative Treatment Options   • ZB added to OSB during manufacture   • Added as a powder at the blender   • Effectively...
Preservative Treatment Options   • OSB Treated with ZB During ManufactureData courtesy of Peter Laks, Michigan Tech Univer...
Preservative Treatment OptionsOther Treatments• What are the active ingredients?    – Vs decay    – Vs termites•   What lo...
Preservative Treatment Specifications• Treated wood off the shelf likely won’t perform• Don’t accept “treatment to refusal...
Preservative Treatment Specifications• For Britco pre-fab homes for tsunami relief  in Indonesia we recommended to FII:  –...
Preservative Treatment Specifications    • For home kits for earthquake relief      in Haiti we recommended to SNC Lavelin...
Design plus Preservative Treatment   • Britco houses in Aceh inspected after 4 years     No evidence of insect attack. Min...
Without Preservative Treatment?• Housing built in Aceh using untreated local  materials attacked by termites after 6 month...
Conclusions• Fit design and treatment to local hazards• Simple design solutions can improve durability• Preservative treat...
Any Questions
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Sdrhcon2011 morris

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Sdrhcon2011 morris

  1. 1. www.fpinnovations.ca Design and Treatment Specifications for Durable Disaster Relief Housing Paul Morris and Jieying Wang Durability and Protection Group FPInnovations
  2. 2. Durability Concerns for Disaster Relief Housing• Need to maximize number of shelters pushes down cost which leads to simplified designs with fewer moisture management features• May be difficult to control construction quality• Temporary structures tend to become permanent• Occupier improvements may increase moisture and termite problems – Addition of untreated wood invites decay and termites – Addition of concrete embeds wood – Addition of cladding or insulation hides termites
  3. 3. Durability Concerns for Disaster Relief HousingIn tropical/subtropical countries• High humidity and rainfall promotes decay• Warm temperatures favour termitesIn extreme northern climates• High occupancy - high interior moisture load• High insulation can promote condensation
  4. 4. Understanding the Decay and Termite Hazard• Scheffer index values indicate decay potential – Derived from equation using rainfall and temperature data• 3 main divisions in termite hazard zones 1. No termites – wood boring beetles may be a problem 2. Reticulitermes and other termite species. No Coptotermes 3. Coptotermes species present, drywood termites also likely• Get expert advice Beetle attack on local hardwood in Aceh
  5. 5. Native termites in Haiti• Subterranean termites Reticulitermes sp.• Drywood termites Cryptotermes sp.• Tree-dwelling termites Nastitutermes sp.
  6. 6. Coptotermes formosanus is the world’s mosteconomically important termite pest
  7. 7. Potential Transport of Coptotermes to Haiti etc.• Termites can be transported via trade or aid. Drywood termites Formosan termites ?
  8. 8. Native termites in Indonesia• Copotermes gestroi mainly in cities – C. formosanus sophisticated cousin• Coptotermes curvignathus mainly in rural areas – C. formosanus hillbilly cousin• Best to consider all Coptotermes as equally bad• ~198 other species
  9. 9. Moisture Management Design Solutions for DurabilityMoisture ManagementThe 4Ds • Deflection – Divert water • Drainage – Let water go • Drying – Allow to dry • Durability – Durable materials Hazleden, D.G., Morris, P.I. 1999.
  10. 10. Moisture Management Design Solutions for DurabilityMoisture ManagementVapour Control inNorthern Climates Vapour/air barrier on the inside
  11. 11. Moisture Management Design Solutions for DurabilityMoisture ManagementVapour Control inTropical Climates Vapour/air barrier on the outside
  12. 12. Design Solutions for Durability• Pitched roof with overhangs on all sides• Minimize penetrations in roof• Minimize rainfall traps• Minimize wood-soil contact – Even if treated, this can attract termites• Minimize penetrations through slab – Termites enter through cracks• Design should be congruent with local custom
  13. 13. Design Solutions for Durability• Support posts above concrete – Prevent wicking of water – Facilitate inspection for termites Ain’t• Raised floor nobody here but us – Reduced flood damage chickens – Improved ventilation – Facilitates inspection and termite control Chickens eating tree- dwelling termites in Cuba
  14. 14. Integrated Termites Management : The 6Ss Developed Countries SuppressionSurveillance Structural BUG OFF Site durability management Slab/foundation Slab/foundation Soil barrier
  15. 15. Integrated Termites Management : The 3Ss Disaster Relief Structural Site management durability Slab/foundation Slab/foundation
  16. 16. Integrated Termites Management : The 3Ss Drywood Formosan termites termites? Tree dwelling termites Structural Site durability management Slab/foundation Slab/foundation Subterranean termitesSlab/Foundation detailing does not stop all termites
  17. 17. Integrated Termite ManagementStructure Durability• Most of our species are not termite resistant• Exceptions: – Western red-cedar is non-preferred but still gets eaten – Eastern white-cedar is non-preferred but still gets eaten – Yellow cedar is the most termite resistant• For most species, treatment is the only option – Note: thermal treatment is not effective vs termites
  18. 18. Preservative Treatment OptionsNot only the lumber needs to be treated• Plywood and PSL can be pressure treated• OSB can be treated during manufacture• LVL very difficult to treat – avoid• I-joists need to be made from treated material• Glulam reacts badly to waterborne treatment – Oil borne preservatives not appropriate for residential – LOSP (Hi-Clear or Cu-nap) treatment not available in Canada – Can treat lamina prior to gluing
  19. 19. Preservative Treatment OptionsMust consider• Regulations in exporting country• Regulations in importing country• Potential for human contact• Building design• Wood species• Local decay and termite hazards
  20. 20. Preservative Treatment Options• Many countries have their own standards – Former British colonies may use British (European) standards – American dependencies use AWPA standards – French colonies may use French ( European) standards• All should be using ISO 21887 Use Classes – UC 1 Interior, dry – UC2 Interior, damp – UC3 Outdoors above ground – UC4 Outdoors ground contact
  21. 21. Preservative Treatment Options• Canadian species mostly impermeable heartwood• Tough to meet foreign treatment standards• After intensive research by FPInnovations and UBC, Canadian standards for outdoor residential lumber have been reduced – No penetration requirement for 2x4 and smaller• These specifications are fine for northern climates• Not for tropical/subtropical regions• Shallow penetration won’t stop termites
  22. 22. Preservative Treatment Options• ACQ and CA Pressure Treatment – Require incising (perforation) - 25% strength loss – React with wood. Stop moving when pressure stops• Borate Pressure+Diffusion Treatment – Does not require incising – Don’t react with wood. Keep moving when pressure stops• New surface-applied penetrating process – Chemistry and process provide deep penetration• In process Zinc-borate treatment of OSB• Surface-treatments
  23. 23. Preservative Treatment Options• ACQ – Copper ethanolamine – algaecide for pools and hot tubs – Quaternary ammonium – disinfectant for surfaces and swabs• CA – Copper ethanolamine – algaecide for pools and hot tubs – Azole – related compounds in dandruff shampoo/athletes foot cream
  24. 24. Preservative Treatment OptionsACQ and CA pressure treatment• Choice of species is critical High-density Incised White Spruce Incised white spruce Incised Pacific Silver fir
  25. 25. Preservative Treatment OptionsTermites eat through a thin shell of treatment
  26. 26. Preservative Treatment OptionsTermites give up if treated shell is thick enough
  27. 27. Preservative Treatment OptionsOr, if they get through, the box is strong enough
  28. 28. Preservative Treatment Options • That is why I favour borate treatment • Borates penetrate our woodRed colour with reagent shows borate penetration
  29. 29. Preservative Treatment Options Borates have a positive perception • Got it on your hands? • Got it on your clothes?. • Got it in your eyes? • Got hungry? • Got boron ?
  30. 30. Preservative Treatment OptionsAbove ground protected termite test 400mm 1000mm m 600mm
  31. 31. Preservative Treatment OptionsPerformance of treated samples in Hawaii 10 9 8AWPA termite rating 7 6 5 4 3 2 1 0 0 2 4 6 8 10 Years of exposure hem-fir control ACZA 2% shell 3% shell 2% through 3% through 2%+DDAC CCA
  32. 32. Preservative Treatment Options• In Hawaii almost all wood-frame homes are 100% borate treated.• Higher loadings required for Formosan termites than in CSA – Use AWPA standards• Borates not for use outdoors exposed to rain – Except under well maintained 3-coat paint finish
  33. 33. Preservative Treatment OptionsNew surface-applied penetrating process• Developed for New Zealand market• Penetrating formulation – Various fungicides and insecticides can be added• Dip or spray plus kiln- conditioning
  34. 34. Preservative Treatment Options New surface-applied penetrating process Treatment results on BC SPF (pine)Red colour with reagent shows penetration
  35. 35. Preservative Treatment OptionsNew surface-applied penetrating process Treatment Rating (10-0) at 2 yrs Control (untreated) 2 Borate (sub-standard) 8 Formulation 1 9 Formulation 2 10 Formulation 3 10
  36. 36. Preservative Treatment Options • ZB added to OSB during manufacture • Added as a powder at the blender • Effectively treats full cross section • ZB is resistant to leaching • Factory coated/sealed boards for exterior use • Field tested in Hawaii**Image courtesy of Peter Laks, Michigan Tech University
  37. 37. Preservative Treatment Options • OSB Treated with ZB During ManufactureData courtesy of Peter Laks, Michigan Tech University
  38. 38. Preservative Treatment OptionsOther Treatments• What are the active ingredients? – Vs decay – Vs termites• What loading is achieved?• What penetration is achieved?• What standards are met?• What long term field test data are available? – Lab testing is not good enough – small samples easily treated• What are the warranties?
  39. 39. Preservative Treatment Specifications• Treated wood off the shelf likely won’t perform• Don’t accept “treatment to refusal”• Get expert advice• Specify standard and subsection• Specify preservative and species• Treatment certificates are worth the value of the paper and the ink• Use third party quality assurance
  40. 40. Preservative Treatment Specifications• For Britco pre-fab homes for tsunami relief in Indonesia we recommended to FII: – ACQ treated plywood sheathing – no cladding supplied – Incised ACQ treated hem-fir for outside – Borate treated SPF for inside protected from rain
  41. 41. Preservative Treatment Specifications • For home kits for earthquake relief in Haiti we recommended to SNC Lavelin: – ACQ or CA treatment for all components because all components were potentially exposed to soil or rain –long termPrototype with untreated components. Photos courtesy of SNC Lavelin
  42. 42. Design plus Preservative Treatment • Britco houses in Aceh inspected after 4 years No evidence of insect attack. Minor instances of decayPhoto courtesy of Jim Creffield, Onwood Consulting
  43. 43. Without Preservative Treatment?• Housing built in Aceh using untreated local materials attacked by termites after 6 months. – Source: representive of aid group• Housing built in Haiti using imported material with treated sheathing and untreated framing – Not a good idea
  44. 44. Conclusions• Fit design and treatment to local hazards• Simple design solutions can improve durability• Preservative treatment is needed vs. termites – Deep penetration essential for termite protection• Most Canadian species resist pressure treatment• Diffusible/pervasive treatments are best• Borates as effective as CCA under cover• Tru-core process looks promising• Specify precisely• Quality assurance is critical
  45. 45. Any Questions

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