Building Code and Building Construction - Questions and Answers
Or when you want to know how construction is supposed to be done.

|
AskCodeMan.com
|
The following Codemen are available to answer your questions:
All Codes and Standards - Jerry Peck, Codeman


Q&A Board links
  • REGISTER

  • FAQ

  • LOGIN

  • Q&A BOARD INDEX

  • View New Questions

  • View Unanswered Questions

  • View Active Questions/Answers

  • Mark Questions as read

  • View Your Questions

  • Go To Your User Control Panel




  • Links to:
  • Construction Litigation Consultants


  • Florida Building Commission

  • Florida Building Codes Online


  • International Code Council

  • ICC Codes Free Online


  • Building Officials and Administrators of Florida




  • Product Approvals
  • Florida Product Approval

  • ICC Evaluation Reports Search

  • Miami-Dade NOA Search




  • Inspector and Contractor License Search
  • Search Florida Licenses




  • Technical links
  • Technical Information page


























































  • Contact Codeman



  • Custom Search

    Hardie Plank siding - Is a water resisting barrier required?

    Hardie Plank siding - Is a water resisting barrier required?

    New postby Jerry Peck - Codeman on Tue Dec 16, 2008 3:37 pm

    (From a phone call question.)

    Codeman,

    Does HardiePlank siding require a weather resisting barrier be installed behind it?

    The local building department said "A weather resisting barrier (WRB) did not used to be required by code, however code now requires a WRB."

    I ask because builders have been installing HardiePlank siding directly over OSB sheathing without installing a WRB over the OSB and behind the HardiePlank siding.

    Jim G., Builder
    Jerry Peck - CodeMan
    AskCodeMan.com

    Construction and Litigation Consultant
    Construction Litigation Consultants, LLC.
    ConstructionLitigationConsultants.com
    User avatar
    Jerry Peck - Codeman
    Site Admin
     
    Posts: 1089
    Joined: Fri Dec 12, 2008 12:06 pm

    Re: Hardie Plank siding - Is a water resisting barrier required?

    New postby Jerry Peck - Codeman on Tue Dec 16, 2008 3:53 pm

    Hi Jim G.,

    The short answer is 'Yes.', however, that short answer is complicated by the vague references to the weather resisting barrier in the HardiePlank installation instructions, which the codes clarify with a "Yes, but", there are limited exceptions.

    The HardiePlank installation instructions state "A water-resistive barrier is required in accordance with local building code requirements. The water-resistive barrier must be appropriately installed with penetration and junction flashings in accordance with local building code requirements. James Hardie will assume no responsibility for water infiltration."

    The code I will reference is the International Residential Code (IRC) as most AHJ (Authorities Having Jurisdiction) have adopted the IRC for residential construction (construction of one-and two-family dwellings and townhouses) 3 or fewer stories high.

    The 2006 IRC, in section R703.2 Water-resistive barrier, states that a water-resistive barrier (WRB) be "free from holes and breaks" and "shall be applied over the studs or sheathing of all exterior walls".

    There is an exception which states:
    - Exception: Omission of the water-resistive barrier is permitted in the following situations:
    - - 1. In detached accessory buildings.
    - - 2. Under exterior wall finish materials as permitted in Table R703.4.
    - - 3. Under paperbacked stucco lath when the paper backing is an approved weather-resistive sheathing paper.

    The 2003 IRC has the same requirement, as does the 2000 IRC, the first year of the International Codes after the model codes merged into one code. Thus, that requirement has been in effect since 2000 in the International Codes, possibly before 2000 in one or more of the previous model codes.

    As I said during our conversation, everyone is aware that wood and water do not go together well, that wood decays when it gets wet and does not dry out quickly enough, that basic construction practices, as well as common sense, dictates that all wood sheathing which is not designed to be left exposed the weather (i.e., which is not 'pressure treated') needs to be protected from the weather and from water which penetrates through non-water-tight siding systems, such as HardiePlank fiber cement lap siding systems.

    Within a few years you can expect to find decaying (rotted) OSB sheathing behind HardiePlank lap siding if the OSB sheathing was not protected with a WRB behind the HardiePlank siding at the time of construction. How many years this takes will depend on the amount of water and moisture getting behind the HardiePlank siding and how long the water and moisture stays there before drying out, if it dries out.

    What is the solution?

    Remove the HardiePlank siding, make sure that all penetrations, including windows, doors, etc., are properly flashed, then properly wrap the house in a WRB (a "building wrap" or "house wrap" product is typically used as the WRB, building felt is not recommended as it does not have the necessary water resistive properties needed for a WRB).

    After properly flashing and wrapping the house - flashing and building wrap go hand in hand and must be done in accordance with the manufacturers' installation instructions, the next step is to properly install NEW HardiePlank siding over the WRB.

    It is as simple as, and as complicated as, doing that.

    Codeman
    Jerry Peck - CodeMan
    AskCodeMan.com

    Construction and Litigation Consultant
    Construction Litigation Consultants, LLC.
    ConstructionLitigationConsultants.com
    User avatar
    Jerry Peck - Codeman
    Site Admin
     
    Posts: 1089
    Joined: Fri Dec 12, 2008 12:06 pm


    Return to Exterior Clading: brick veneer; stucco; siding - vinyl, wood, cementitious (such as HardiePlank), hardboard (such as Masonite siding); EIFS



    Who is online

    Users browsing this forum: No registered users and 1 guest



    www.AskCodeMan.com
    cron