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11/17/2017Overview Building Insulation Retrofit Strategies Exterior Insulation Approaches– Insulation and Separate Cladding– Exterior Insulation and Finish System (EIFS)– Insulated Metal PanelsPeter BakerExterior Insulation:Strategies and Cladding Attachment Cladding Attachment ResearchNovember 16, 2017Exterior Insulation and Cladding AttachmentInsulation Retrofit Existing buildings are often un‐insulated/poorlyinsulated Insulation options are:Insulation Retrofit OptionsExterior Insulation and Cladding Attachment– Cavity fill– Interior insulation– Exterior insulationExterior Insulation and Cladding Attachment1

11/17/2017Cavity Fill Insulation Cavity fill insulation is most common retrofit –but has limitationsInterior Insulation Interior insulation retrofit concerns– Continuity of insulation (partition walls, floors, etc.)– Loss of floor space– Occupant disruption– 4” cavity for older wood frame– ¾” cavity for mass masonry Desirable if exterior appearance isneeded/wanted to be maintained Often the best approach for historic buildings Not ideal from a building physics perspectiveExterior Insulation and Cladding AttachmentExterior Insulation and Cladding AttachmentExterior Insulation Exterior insulation retrofit– Ideal from a building physics perspective– Can be completed with less disruption to occupants– May come at a higher cost than other approachesExterior Insulation New approach!New approach?Not a new approach Pesky Canadians Benefits discussed in Canadian Building Digestsproduced by the National Research Council ofCanada in the 1960’sExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment2

11/17/2017Exterior InsulationExterior Insulation CBD 44 (W.P. Brown, A.G. Wilson) – Published in1963 The “Perfect” Wall“Application of insulation over the entire exterior of a wallprovides an ideal solution to the problems presented bythermal bridges.” Increase overall thermalperformance Minimize thermal bridges Minimize potentialfor air leakagecondensation Improve air tightness? Improve rainwatermanagement?“It should be stressed that many of the thermal bridges occurringin present‐day construction can be avoided, or their effectsminimized, if they are recognized in the early stages of design.”Exterior Insulation and Cladding Attachment1980s ON – a “weird” builderExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment1990s ON – a “good” builderExterior Insulation and Cladding Attachment3

11/17/20172000s ON – a “typical” builderExterior Insulation ApproachesExterior Insulation and Cladding AttachmentExterior Insulation Approaches Insulation and cladding(discrete components)Exterior Insulation and Cladding AttachmentExterior Insulation and Cladding AttachmentExterior Insulation Approaches Insulation and cladding(discrete components) Exterior Insulation and FinishSystem (EIFS)Exterior Insulation and Cladding Attachment4

11/17/2017Exterior Insulation Approaches Insulation and cladding(discrete components) Exterior Insulation and FinishSystem (EIFS) Insulated Metal Panels (IMP)– Used as a complete enclosureExterior Insulation and Cladding AttachmentBrick VeneerExterior Insulation Approaches Insulation and cladding(discrete components) Exterior Insulation and FinishSystem (EIFS) Insulated Metal Panels (IMP)– Used as a complete enclosure– Used as an insulated claddingExterior Insulation and Cladding AttachmentBrick Veneer Brick veneer has some of the longest historywith exterior insulation– Long history more common– More common less questions Not always well doneExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment5

11/17/2017Brick VeneerBrick VeneerExterior Insulation and Cladding AttachmentExterior Insulation and Cladding AttachmentBrick VeneerBrick Veneer Alternate details and support options exist Support systems for brick can be modifiedfor other building elements– Decks– Balconies– Canopies– Etc.Exterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment6

11/17/2017Brick VeneerExterior Insulation and Cladding AttachmentOther Claddings For insulation less than 1.5” – direct attachment of claddingthough insulation back to the structure is practical For insulation greater than 2” – a secondary claddingsupport structure is often needed.Brick VeneerExterior Insulation and Cladding AttachmentOther Claddings Lighter weight claddings (metal/wood/fibercement)– Less common less experience– Less experience more questions Cladding support systems historically donepoorly Systems are getting betterExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment7

11/17/2017Other CladdingsOther Claddings Single “z‐furring”– Poor thermal performance (steel stud wall onthe exterior – why bother?)Exterior Insulation and Cladding AttachmentOther Claddings Single “z‐furring” Double “z‐furring”– Can be made to function reasonably wellprovided that two layers of insulation are used.– Often designed with first layer bridginginsulation and second layer creating a gapbehind the cladding single “z‐furring”Exterior Insulation and Cladding AttachmentExterior Insulation and Cladding AttachmentOther Claddings Single “z‐furring” Double “z‐furring”Exterior Insulation and Cladding Attachment8

11/17/2017Other CladdingsOther Claddings Single “z‐furring” Double “z‐furring” Clip and “z‐furring” orhat channel– Metal clip– Fiberglass clipExterior Insulation and Cladding AttachmentOther CladdingsExterior Insulation and Cladding AttachmentOther Claddings Single “z‐furring” Double “z‐furring” Clip and “z‐furring” or hatchannel– Metal clip– Fiberglass clip Attach furring directly backto structure throughinsulationExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment9

11/17/2017EIFS Exterior Insulation and FinishSystem (EIFS)– Lightweight– Cost effective– Water managed Minimal Thermal Bridging R‐4 per inch System has a tainted historyExterior Insulation and Cladding AttachmentEIFSEIFS Commonlyinstalled usingadhesive The adhesivecan also formthe drainagegap in watermanagedsystemsExterior Insulation and Cladding AttachmentInsulated Metal Panels Insulated Metal Panels (IMP)– Lightweight– Moderate cost– Water managed Minimal Thermal Bridging R‐7.5 per inch Can be an excellent enclosuresystem Requires some consideration forretrofit applicationsExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment10

11/17/2017Insulated Metal Panels Can be used as both acomplete enclosure systemInsulated Metal Panels Can be used as both acomplete enclosure system Can also be used as aninsulated cladding systemExterior Insulation and Cladding AttachmentInsulated Metal Panels Attachment often to metal hatchannel or z‐furring– In retrofit applications out ofplane walls can requirespecial adjustable systems orshimsExterior Insulation and Cladding AttachmentExterior Insulation and Cladding AttachmentInsulated Metal Panels IMP as a complete enclosuresystem– Provides all enclosurefunctions into a single system– System design as intended bypanel manufacturesExterior Insulation and Cladding Attachment11

11/17/2017Insulated Metal Panels IMP as a complete enclosuresystem– May require special detailingfor compartmentalization atfloors or partition walls,particularly in retrofitapplicationsExterior Insulation and Cladding AttachmentInsulated Metal Panels IMP as an insulated claddingsystem– Provides thermal insulationand cladding– Rain water management andair tightness are provided byother elements– Modification tomanufacturers intendeddesignExterior Insulation and Cladding AttachmentInsulated Metal Panels (Retrofits) IMP as an insulated cladding system– Need to fill space between thepanel and back up wall toprevent air by‐pass of theinsulation– Can simplify certain details suchas interfaces at balconies, lowerroofs, and compartmentalization– More in line with commonconstruction detailingExterior Insulation and Cladding AttachmentCladding Support System:Direct Attachment ThroughInsulationExterior Insulation and Cladding Attachment12

11/17/2017BackgroundBackground Industry trend to using exterior rigid insulation– Increased thermal value– Condensation resistance– Increased air tightness (possibly)– Increased rainwater management (possibly) Need to develop a means to attach cladding over thick layers ofexterior insulation that can meet the following requirements:– Provides good thermal performance– Low cost– Easy to construct/install (low cost)Exterior Insulation and Cladding Attachment Current pneumatic nailers have maximum fastener lengths of 3”to 3.5” which limits insulation thicknesses to 1.5” max– 3.5” fastener, ¼” to ½” siding, 1 ½” embedment (3.5‐0.5‐1.5 1.5” max insulation) Therefore, for insulation greater than 1.5” direct attachment ofcladding though the insulation back to the structure is often notpracticalExterior Insulation and Cladding AttachmentDirect Attachment Through InsulationDirect Attachment Through InsulationMasonryStructureWoodstructure2x4 framingattached tosurface ofmasonry2” to 4” ofexterior rigidinsulation2” to 4” ofexterior rigidinsulation1x3 woodfurring strips1x3 woodfurring stripsExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment13

11/17/2017Direct Attachment Through Insulation Lots of practical experience with this approach for lightweightcladding systems over thick layers of insulation (severaldecades). Approach has demonstrated very good long term performance High resistance from industry– Compression resistance of insulation– Long term creep“Myths” “Does the insulation crush under load?” YES! Loading a system until failure (500lbs to 1000lbs ormore per screw fastener) will crush most rigidinsulations .Unfortunately that is the wrong questionExterior Insulation and Cladding AttachmentExterior Insulation and Cladding Attachment“Myths” “Does the insulation crush under a load similar towhat will be imposed on it in a cladding supportapplication?” The answer is no!.Context is importantExterior Insulation and Cladding AttachmentTypical Loads Typical cladding weights (psf)lowhighVinyl0.61.0wood1.01.5fiber cement3.05.0stucco10.012.0adhered stone veneers17.025.0Exterior Insulation and Cladding Attachment14

11/17/2017Typical LoadsDesign Criteria Typical weights per fastener (lbs)fastener spacing (in)16" x 16" 16" x 24"24" x 24"area/fastener nt8.913.320.0stucco21.332.048.0adhered stone veneers44.466.7100.0Exterior Insulation and Cladding AttachmentBSC Cladding Attachment Research Began in 2011 Looking to expand onprevious research Broken into two sections: mechanics of thecladding attachmentsystem long termenvironmentalexposureExterior Insulation and Cladding Attachment Acceptable deflection not ultimate capacity governs What is acceptable deflection?– Movement a cladding system can accommodatewithout physical damage or exceeding aesthetictolerances Proposed limit of 1/16” vertical deflectionExterior Insulation and Cladding AttachmentFull System Laboratory Tests Looked at initial responsefull system capacity aswell as long termsustained loading Used full scale samples tolimit variations in fastenerinstallationExterior Insulation and Cladding Attachment15