SoCal1
New Member
obviously a few of you are not up to date and it shows.Hackney plumbing said:According to the document thats posted drywall is not allowed no matter what the sealing method is.
Section R702.4.2 allows a glass mat gypsum backer in a shower.
Tile bonded directly to gypsum board was what the code was written to stop no matter how you read or twist it. Although the use of gypsum board with a bonded waterproof membrane is not referenced in Section R702.4.2 of the IRC, it may be allowed by code officials per Section R104.11 if it is shown to comply with the intent of the code and be at least equivalent to the options listed. One of the acceptable options called out in Section R702.4.2 is glass mat gypsum backers. A glass mat gypsum backer is comprised of a gypsum core that is laminated with glass mat face. The reason that gypsum-based product is listed in the code is because the glass mat face protects the gypsum core against moisture penetration. The installation of Schluter Kerdi over gypsum board produces an equivalent system per IRC R104.11. The gypsum core is fully protected against moisture penetration. IRC Section R104.11 deals with alternative materials and methods of construction and has been part the code from the beginning. It allows the flexibility necessary for a building official to accept any viable material or method of construction as long as it satisfies the intent of the code.
IRC R104.11 said:"R104.11 Approval of Alternative Materials, Design, and Methods of Construction and Equipment:
The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code. Compliance with the specific performance-based provisions of the International Codes in lieu of specific requirements of this code shall also be permitted as an alternate."
http://www.icc-es.org/reports/pdf_files/ICC-ES/ESR-2467.pdf
ICC Evaluation Service said:
IRC P2709.2 said:P2709.2 Lining required.
The adjoining walls and floor framing enclosing on-site built-up shower receptors shall be lined with one of the following materials:
1. Sheet lead;
2. Sheet copper;
3. Plastic liner material that complies with ASTM D 4068 or ASTM D 4551;
4. Hot mopping in accordance with Section P2709.2.3; or
5. Sheet-applied load-bearing, bonded waterproof membranes that comply with ANSI A118.10.
The lining material shall extend not less than 2 inches (51 mm) beyond or around the rough jambs and not less than 2 inches (51 mm) above finished thresholds. Sheet-applied load bearing, bonded waterproof membranes shall be applied in accordance with the manufacturer’s instructions.
as far as I'm concerned I approve gypsum board per IRC P2709.2, ESR-2467 and Schluter Kerdi Installation Instructions and the IRC R104.11 gives me that option. I'm not going to be hard headed and keep blinders on with new technologies out there. I will not allow or approve tile set directly to gypsum board or organic adhesives in a shower.