Building Science

Best Practices for Continuous Insulation in Exterior Walls

Con­tin­u­ous insu­la­tion (CI) in exte­ri­or walls is an essen­tial and required design com­po­nent of ener­gy effi­cient and high per­form­ing build­ings. In fact, the Amer­i­can Soci­ety of Heat­ing, Refrig­er­at­ing and Air-Con­di­tion­ing Engi­neers (ASHRAE 90.1) and the Inter­na­tion­al Ener­gy Con­ser­va­tion Code (2015 IECC) require con­tin­u­ous insu­la­tion in both com­mer­cial and res­i­den­tial applications.The ASHRAE Stan­dard 90.12013 defines con­tin­u­ous insu­la­tion as insu­la­tion that is uncom­pressed and con­tin­u­ous across all struc­tur­al mem­bers with­out ther­mal bridges oth­er than fas­ten­ers and ser­vice open­ings. It is installed on the inte­ri­or, exte­ri­or, or any non see through sur­face of a building’s enve­lope. The rise in the use of CI has occurred because of both eco­nom­ic and envi­ron­men­tal rea­sons. Build­ings designed with CI save mon­ey because CI stops ther­mal bridg­ing; there­fore, less ener­gy is required for heat­ing and cool­ing a build­ing. Uti­liz­ing CI also reduces costs asso­ci­at­ed with mechan­i­cal ven­ti­la­tion, heat­ing, and cool­ing. The use of CI is good for the envi­ron­ment because less ener­gy con­sump­tion means few­er emis­sions of green­house gas­es, a known cause of glob­al cli­mate change. Con­tin­u­ous insu­la­tion is stan­dard prac­tice across all cli­mat­ic regions of the Unit­ed States and saves both ener­gy and mon­ey. Best prac­tices for con­tin­u­ous insu­la­tion in exte­ri­or walls con­sid­er ther­mal per­for­mance, fire, and mois­ture resis­tance in the design and con­struc­tion.

R-Value Requirements in Eight Climate Zones - Continuous Insulation

Best prac­tices for CI in the exte­ri­or walls fol­low the ASHRAE 90.1 and 2015 IECC codes and stan­dards. The stan­dards spec­i­fy the amount of insu­la­tion required, based on the build­ings cli­mate zone, to elim­i­nate ther­mal bridg­ing and increase the effec­tive R‑value in a wall assem­bly. Builders, archi­tects, and design­ers uti­lize CI to cre­ate ener­gy effi­cient, air­tight struc­tures that save both mon­ey and reduce green­house emis­sions.

Fire Resistance - Continuous Insulation

Unfor­tu­nate­ly, the major­i­ty of con­tin­u­ous insu­la­tion solu­tions are com­bustible mate­ri­als. This makes the CI require­ments more dif­fi­cult to meet because the Inter­na­tion­al Build­ing Code (IBC) requires mak­ing walls of non­com­bustible com­po­nents and eval­u­at­ing the walls by indus­try stan­dards of fire resis­tance. Two indus­try stan­dards gauge the fire resis­tance of wall assem­blies: the ASTM E119, Fire Tests of Build­ing Con­struc­tion and Mate­ri­als and the ASTM E2257 Stan­dard Test Method for Room Fire Test of Wall and Ceil­ing Mate­ri­als and Assem­blies.

  • ASTM E119 (and-and ULC-S101) deter­mines a wall assembly’s capac­i­ty to stop a fire from expand­ing. Build­ing codes give fire rat­ings to fire sen­si­tive areas in walls, par­ti­tions, roofs, and floor/​ceilings
  • ASTM E2257 is a fire test that shows how much the wall and ceil­ing cause a fire to grow in an area and the pos­si­bil­i­ty of the fire spread­ing beyond the area, under sim­u­lat­ed con­di­tions

Oth­er stan­dards for fire resis­tance include the NFPA 286: Stan­dard Meth­ods of Fire Tests for Eval­u­at­ing Con­tri­bu­tion of Wall and Ceil­ing Inte­ri­or Fin­ish to Room Fire Growth, the NFPA 101: Life Safe­ty Code and ASTM E84: Sur­face Burn­ing Char­ac­ter­is­tics of Build­ing Mate­ri­als.

  • The NFPA 286 is for walls and ceil­ings and per­tains to the test­ing of mate­ri­als with fire.The stan­dard shows how much the room’s dif­fer­ent ele­ments on the walls and ceil­ings, includ­ing the wall­pa­per, con­tribute to the spread of fire
  • The NFPA 101 is the sole doc­u­ment that cov­ers life safe­ty
  • ASTM E84 deter­mines the rel­a­tive burn­ing behav­ior of the mate­r­i­al by observ­ing its flame spread and smoke den­si­ty

Moisture - Continuous Insulation

The use of con­tin­u­ous insu­la­tion as an addi­tion­al lay­er can inhib­it a wall’s abil­i­ty to release trapped mois­ture from with­in the wall assem­bly. The mois­ture can cause mildew, mold, and rot to devel­op. Uti­liz­ing an air and mois­ture bar­ri­er, along with CI, stops ther­mal con­vec­tion (drafts) and ther­mal con­duc­tion and cre­ates a pleas­ant, com­fort­able envi­ron­ment for the occu­pants of the build­ing.

Bautex™ Block Wall Assembly - - - Best Practices for Continuous Insulation

Best prac­tices for con­tin­u­ous insu­la­tion in exte­ri­or walls should meet, if not exceed, the codes and stan­dards of the ASHRAE 90.1 and 2015 IECC. Exte­ri­or walls con­struct­ed with con­tin­u­ous insu­la­tion should be water, air, and fire resistant.The Bau­tex Block Wall Assem­bly meets and sur­pass­es rec­om­men­da­tions for best prac­tices for con­tin­u­ous insu­la­tion in exte­ri­or walls.

  • The Bau­tex Block Wall Sys­tem pro­vides an R‑14 con­tin­u­ous insu­la­tion; far exceed­ing 2015 IECC rec­om­men­da­tions for mass wall assem­blies. Mea­sure­ment of R‑value is in accor­dance with ASTM C 518 – 10.The Blocks stop ther­mal bridg­ing and cre­ate an insu­lat­ed and ener­gy effi­cient build­ing enve­lope that is com­pli­ant with the lat­est build­ing codes
  • The Bau­tex Air and Mois­ture Bar­ri­er lim­its ther­mal con­vec­tion by pre­vent­ing the infil­tra­tion of air and mois­ture to the inte­ri­or of the struc­ture
  • The Bau­tex Wall Sys­tem has an ASTM E119 fire rat­ing of four hours, and ASTM E84 val­ues for flame speed of zero and smoke devel­op­ment of twen­ty. Since the Blocks meet the ASTM E84 and NFPA 286 they meet the NFPA 101 code

The Bau­tex Wall Sys­tem is also easy to install, noise reduc­ing and storm-resis­tant. Bau­tex Blocks can be uti­lized in both com­mer­cial and res­i­den­tial build­ings and are the ide­al choice for best prac­tices for con­tin­u­ous instal­la­tion in exte­ri­or walls. Wrap­ping a building’s enve­lope with a lay­er of CI, along with an air and mois­ture bar­ri­er increas­es the effec­tive R‑value, elim­i­nates ther­mal con­vec­tion, and pro­vides for a com­fort­able indoor envi­ron­ment.