Washington Administrative Code

(1) This chapter applies only to temporary worker housing as defined in RCW 43.70.334 through 43.70.340 and chapter 70.114A RCW.(2) TWH meeting the requirements of subsection (1) of this section must:(a) Be located on a rural worksite; and(b) Comply with:(i) Chapter 246-358 WAC (…

The following definitions apply throughout this chapter unless the context clearly indicates otherwise:(1) "Alter" or "alteration" means any change, major repair, addition or modification in construction.(2) "Architect" means an individual licensed by chapter 18.08 RCW to practic…

The department of health:(1) Is authorized and directed to enforce all the provisions of this chapter, according to the laws as enacted by the Washington state legislature.(2) Has the power to issue written interpretations of this chapter as long as the interpretations are in con…

(1) Department of health authority. The department has authority to enter any building or area used for TWH, at reasonable times to:(a) Inspect the site for compliance with this chapter and related standards; and(b) Determine, based on reasonable cause, if a building or condition…

(1) The department of health may deny, suspend, modify, or revoke a permit in any case in which it finds that there has been a failure or refusal to comply with the requirements of chapter 70.114A RCW or this chapter.(2) The department of health's notice of a denial, suspension, …

An applicant may apply for a minor variance from the requirements of this chapter by filing a written request with the department of health. As used in this section, a minor variance means an alternative method of construction or design that must achieve the same result as the re…

(1) The department of health will require construction documents to be prepared by an architect or engineer for any construction described under:(a) WAC 246-359-600, alternate construction;(b) WAC 246-359-710, installation requirements for factory assembled structures;(c) WAC 246…

(1) To have construction documents reviewed the applicant must submit to the department of health:(a) A completed and signed application, on a form provided by the department of health, for each structure (individual building);(b) The required plan review fee, according to WAC 24…

(1) The department of health will notify the applicant in writing:(a) With a "plan review approval letter" when the construction documents meet the requirements of this chapter; or(b) With a "not approved letter" when the construction documents do not meet the requirements of thi…

(1) The department of health will issue a construction permit when:(a) Construction documents are approved according to WAC 246-359-080; and(b) Permit and inspection fees are paid according to WAC 246-359-990.(2) Construction can begin after the applicant is issued a construction…

(1) Permit expiration. The permit will be considered null and void one year from the date the permit was issued if the applicant:(a) Has not initiated the work authorized by the permit;(b) Suspends or abandons the authorized work at any time after the work has begun by not callin…

(1) Construction of TWH allowed by this chapter can only begin after a construction permit has been issued by the department of health as described in WAC 246-359-090.(2) A person who begins any work without a construction permit will be subject to an investigation and an investi…

The department of health or its designee, when notified by the applicant in writing has authority to conduct all of the inspections described in this section.(1) Site/foundation inspection. To be made after excavations for footings are complete, and after any required forms and r…

(1) The department of health, upon notifying the applicant in writing, will order work to be stopped when the work being done is found to be contrary to:(a) The approved plans;(b) The requirements of this chapter; or(c) Other laws or ordinances required and necessary to enforce t…

(1) The department of health will issue a "certificate of completion" when:(a) The inspector determines the project is completed in compliance with the approved construction documents;(b) The department of health determines the project is in compliance with this chapter and relat…

(1) The site used for TWH must be:(a) Adequately drained and not subject to periodic flooding;(b) Located a distance of at least two hundred feet from all surface water;(c) Located so the drainage from and through the TWH will not endanger any domestic or public water supply;(d) …

(1) Rooms used for sleeping purposes must have a minimum of fifty square feet of floor space for each occupant.(2) Rooms used for cooking, living, and sleeping must have a minimum of one hundred square feet per temporary worker. Sanitary facilities shall be provided for storing a…

(1) When building with wood or CMU as required by WAC 246-359-200 through 246-359-580 the following requirements apply:(a) Floor area must be limited to three thousand six hundred square feet per building;(b) Height must be limited to one story; and(c) All floor surfaces must be …

(1) Concrete used for footings and foundations must have a minimum compressive strength of two thousand pounds per square inch (psi). Concrete must be mixed and delivered in accordance with the requirements of ASTM C94 (Ready-Mix Concrete), or may be field mixed. Field mixed conc…

(1) Buildings constructed using wood materials must follow the requirements of WAC 246-359-001 through 246-359-340 to comply with this chapter.(2) Wood structural members in contact with the ground, and/or concrete must be pressure treated and must bear the proper grade mark of a…

(1) All lumber and plywood used for wood foundation systems must be pressure treated and bear the grade mark FDN (foundation grade) or better.(2) Where FDN lumber and plywood is cut or drilled after treatment, the cut surface must be field treated with a preservative that is desi…

(1) Girders.(a) Girders supporting floor joists must be a minimum four-by-six Hem-Fir #2, spaced not more than eight feet on center, and placed at least twelve inches above ground.(b) Girders must be continuous, or must be spliced over supports. When a girder is spliced over a su…

(1) Exterior walls and interior partitions must be framed as follows:(a) Studs must be minimum two-by-four wood, Hem-Fir stud grade or better, spaced not more than sixteen inches on center, support no more than one ceiling and one roof, nor exceed eight feet in height for exterio…

(1) All weather-exposed surfaces must have a weather resistive barrier. Such barrier must be of waterproof building paper or asphalt saturated felt. Building paper, felt, or equivalent materials must be covered with siding as a protection against damage. Weatherproof sheathing ma…

(1) Roof framing must have a minimum slope of three units vertical to twelve units horizontal, and must be framed with one of the following methods:(a) Factory built trusses. Installed per manufacturer's directions and spaced not more than twenty-four inches on center. Roof truss…

(1) Notching at the ends of ceiling joists must not exceed one fourth the depth. Notches in the top or bottom must not exceed one sixth the depth and must not be located in the middle one third of the span.(2) Holes bored in ceiling joists must not be within two inches of the top…

Roof sheathing shall be structural wood panels (plywood, OSB) with a minimum five-eighths inch thickness, grade stamped for use and span. Secure roof sheathing panels to the roof framing with 8d common nails, spaced six inches on center at the edges and twelve inches on center at…

Roof sheathing must be protected by installing a material that has been designed as a roofing covering product. Installation of the selected roof covering material must be according to manufacturer's instructions and industry standards.[Statutory Authority: RCW 70.114A.081. WSR 9…

(1) Ventilation must be provided for enclosed roof framing spaces by providing sixteen-mesh screened openings at:(a) The eaves;(b) The gable ends;(c) The ridge; or(d) Any combination of (a) through (c) of this subsection.(2) The minimum amount of ventilation openings must be at t…

All nailing must be completed according to Table 340.Table 340Nailing Scheduleconnectionnailing11. Joist to sill or girder, toenail3-8d2. Bridging to joist, toenail each end2-8d3. 1" x 6" subfloor or less to each joist, face nail2-8d4. Wider than 1" x 6" subfloor to each joist, f…

(1) Framing members must bear on a two-inch nominal thickness pressure treated plate anchored to the CMU wall with one-half inch diameter bolts. The anchor bolts must be spaced at maximum of six feet on center and a minimum of twelve inches from end of each plate member, and must…

Buildings constructed using CMU must follow the requirements of WAC 246-359-001 through 246-359-170 and WAC 246-359-400 through 246-359-580 to comply with this chapter.[Statutory Authority: RCW 70.114A.081. WSR 99-03-065, § 246-359-400, filed 1/18/99, effective 2/18/99.]

(1) Solid masonry units must not be used.(2) Water. Water used in mortar or grout must be clean and free of deleterious amounts of acid, alkalis or organic material or other harmful substances.(3) Cement. Cementitious materials for:(a) Grout must be either lime or portland cement…

(1) Footings for load bearing CMU walls must be continuous concrete having a minimum twelve width-by-ten inch thickness, placed a minimum eighteen inches below the finished grade, and reinforced with a minimum of two No. 4 continuous rebar.(2) Foundations must be one of the follo…

(1) CMU must be laid in a running bond pattern with the units in each successive course overlapping the joints in the course below. At corners the length of the corner unit must alternate direction on each successive course.(2) The mortar must be sufficiently plastic and the unit…

(1) Floors must be concrete slab on grade and not less than three and one-half inches thick reinforced with "6 x 6 10/10 welded wire mesh (wwm)," and be constructed with not less than four sacks of cement per cubic yard.(2) When concrete is used as the finished floor it must be s…

(1) Wall thickness. CMU blocks used for bearing walls must have a minimum nominal thickness of six inches.(2) Rebar cover. All rebar must be:(a) Placed within the openings of the hollow masonry units;(b) Completely embedded in mortar or grout; and (c) Have a minimum cover of thre…

(1) All habitable rooms and spaces must be provided with windows the total area of which must be not less than one-tenth of the floor area.(2) At least one-half of each required window must be able to open for ventilation purposes.(3) Every sleeping room must have at least one op…

TWH habitable structures:(1) Must have a primary entrance, which is at a minimum, three foot-by-six foot eight-inch exit door made of solid core wood or other material designed for use as an exterior door.(2) Must have at least two exit doors when accommodating ten or more occupa…

(1) Door landings. Every door must have, at a minimum, a floor area or landing with:(a) A width not less than the width of the door or the width of the stairway served, whichever is greater; and (b) A length not less than thirty-six inches.(2) Stairways. Every stairway having two…

(1) Floors must be finished to provide an easily cleanable surface. Acceptable finishes are paint, sheet vinyl, tile, or other materials designed for use as a finished floor surface. All materials must be installed per manufacturer's instructions.(2) Walls and ceilings must be fi…

(1) The installation of electrical systems and wiring must comply with the state electrical code, chapter 246-46 WAC, as administered by the department of labor and industries and according to the number of outlets or light fixtures required in subsection (2) of this section.(2) …

(1) TWH must be provided with approved smoke detectors installed according to the manufacturer's instructions.(2) Smoke detectors must:(a) Be installed in each sleeping room;(b) Be installed at a central point in a corridor or area which gives access to each separate sleeping roo…

(1) The installation of plumbing systems, fixtures, and fittings must comply with the Plumbing Code as adopted by the state building code council, chapters 51-46 and 51-47 WAC, except for the following parts of the plumbing code which do not apply:(a) The provisions for "water co…

(1) All food-handling and eating facilities must meet the requirements of WAC 246-358-125.(2) Common food-handling facilities. Common food-handling facilities must:(a) Be covered and enclosed or screened;(b) Provide mechanical ventilation in all enclosed food-handling facilities …

The installation of heating, ventilating, cooling, refrigeration systems, and other miscellaneous heat producing equipment must meet the requirements of the mechanical code as adopted by the state building code council, chapter 51-52 WAC, except as exempted in WAC 246-359-575.[St…

TWH as defined in this chapter are exempt from all versions of the Washington state energy code and the ventilation and indoor air quality code.[Statutory Authority: Chapter 70.114A RCW and RCW 43.70.334 through 43.70.340. WSR 15-13-091, § 246-359-575, filed 6/15/15, effective 1/…

(1) When the temperature in habitable rooms will fall below seventy degrees Fahrenheit, the TWH must provide heating systems to maintain a temperature of seventy degrees Fahrenheit. Heating systems must be permanent, installed, and comply with DOSH and chapter 246-358 WAC.(2) Ins…

Installed LP-gas, such as propane, propylene, butane, normal butane or isobutane, and butylenes, must comply with the state fire code and fuel gas code, as adopted by the state building code council.[Statutory Authority: Chapter 70.114A RCW and RCW 43.70.334 through 43.70.340. WS…

(1) The department of health will allow alternate construction to the requirements stated in WAC 246-359-180 through 246-359-440 of this chapter when the plans are designed and stamped by an engineer or architect licensed to practice in the state of Washington, and meet applicabl…