The owner or installer of a manufactured/mobile home must obtain an installation permit from the county planning and building department, 114 South 2nd Street, before a manufactured/mobile home can be sited within the unincorporated areas of the county. A dealer and/or individual may not deliver a manufactured/mobile home to the location site until he has verified that the owner or installer has obtained an installation permit from the building department. The building department shall issue the installation permit after it has been determined that all applicable building, zoning and any other regulations adopted by the county of Columbia have been satisfied.

The installation permit shall be valid for a period of one year from the date of issuance, and shall be issued for the location of a specific manufactured/mobile home on a specific lot of record or manufactured/mobile home space. Location of a different manufactured/mobile home in the same location or of the same manufactured/mobile home in a different location shall cause the permit to became null and void and shall require a new installation permit and fee to be paid by the applicant.

Failure to meet the conditions of the installation permit within the one-year period shall require reapplication; provided, that an extension of the original installation permit for a period of 180 days may be granted by the building official, or his designee, for good cause shown upon a request by the applicant prior to expiration of the original period.

The application must be submitted by the property owner or installer, and must provide the following information to be considered complete:

The installer shall request an inspection after all aspects of the installation other than the installation of skirting has been completed. The building inspection division will inspect the installation within 48 hours after receiving the request. If the inspection is not completed within the 48-hour period, the tenant or owner may occupy the manufactured/mobile home at his or her own risk.

Occupancy before inspection does not imply approval. The building official will certify the installation after it has been determined that all requirements of this chapter and other applicable regulations of the county of Columbia have been made.

All manufactured/mobile homes shall be installed in compliance with the regulations stated in this chapter.

A HUD-labeled manufactured/mobile home shall be installed in compliance with the manufactured/mobile home manufacturer's installation recommendations. These recommendations must be approved by HUD. The manufacturer shall send one copy of its approved installation recommendations to the purchaser of the manufactured/mobile home. This copy shall be in the manufactured/mobile home and available at the time of inspection. A manufactured/mobile home must be labeled by HUD or a current Labor and Industries label or placement cannot be permitted.

No person, firm, partnership, corporation or other entity may install a manufactured/mobile home unless they are the owners of the manufactured/mobile home, a licensed manufactured/mobile home dealer, or a contractor registered under RCW 18.27.117. Any manufactured/mobile home dealer, contractor or subcontractor doing installation work on the manufactured/mobile home must be a certified Washington State mobile home installer.

All water and sewer connections shall be installed according to the International Plumbing Code and the requirements of the Columbia County health department.

Each manufactured/mobile home installed within any 100-year floodplain shall be placed on a permanent foundation that meets the construction requirements of the International Building Code and/or International Residential Code or subsequently adopted building codes.

Each manufactured/mobile home placed on a permanent foundation or basement shall have all running gear, including axles, removed.

Each manufactured/mobile home installed on a parcel of land outside of a designated manufactured/mobile home park shall have the towing tongue removed.

Steps shall be required for all exit doors and shall be a minimum of 36 inches wide and shall not exceed an eight-inch rise with a minimum nine-inch tread. More than three steps in height shall require one handrail, which shall be 34 to 38 inches above the nose of the step. Exception: Stairs and stairways that parallel the exterior wall of the manufactured/mobile home will require only one handrail on the open sides of the stairway if the width is 44 inches or less.

Manufactured/mobile homes designed as dwellings and designated as such by the state of Washington insignia may not be used as storage units. Modifications to make them uninhabitable will not be used for an exception.

Commercial coach and manufactured/mobile home use may not be interchangeable; i.e., manufactured/mobile homes may be used only for residential purposes and commercial coaches may not be used for residential purposes. They may only be used in the intended manner.

Temporary Installation – During Construction.

Temporary Installation of an RV. The temporary installation of an RV for recreational purposes or as an accessory dwelling shall not exceed 15 days, and does not need a permit. If placement extends longer than 15 days, proper placement permits must be obtained from the building department and the sewage disposal method must be permitted and have Columbia County health department approval.

Footings shall be constructed of:

Footings shall be:

Installers shall follow manufacturer's instruction for blocking where available. On older manufactured/mobile homes where manufacturer's installation instructions are not available. A manufactured/mobile home with more than one section must have center blocking at end walls and at any other point of connection of the section of the manufactured/mobile home that is a ridge beam bearing support. Blocking is also required at both ends of a door opening four feet or more in width on an exterior wall.

If a manufactured/mobile home requires footings on its exterior perimeter, the footings shall be installed a minimum of 18 inches below finish grade. Footings for the main frame long members must be recessed only if frost heave is likely to occur.

Footings shall be constructed so that 75 percent of the area under the manufactured/mobile home has at least 18 inches of clearance between the bottom of the main chassis members and the ground level. The area beneath furnace crossovers and fireplaces, however, must always have at least 18 inches of clearance. At no point under the manufactured/mobile home may clearance be less than 12 inches.

A pier may be made of a single stack of eight-inch by eight-inch by 16-inch blocks if the blocks are not stacked more than three blocks high. A pier made of a single stack of blocks shall be installed at a right angle to the main frame member and shall be capped with no more than two two-inch by eight-inch by 16-inch wood blocks or one four-inch by eight-inch by 16-inch concrete block.

A pier may be made of a double stack of eight-inch by eight-inch by 16-inch blocks if the blocks are not stacked more than five blocks high. Each row of blocks in such a pier shall be stacked at right angles to the abutting row of blocks. A wood block must be of hem fir, Douglas fir, or spruce pine fir. The pier shall be capped with two two-inch by eight-inch by 16-inch wood and concrete blocks. The pier shall be installed so that the joint between the cap blocks is at right angles to the main frame member.

A pier may be made with more than five blocks if the stacked blocks are filled with 2,000 psi concrete or mortar. A licensed architect or professional engineer must approve a foundation system that includes a pier that is higher than 72 inches (nine blocks) high, or when more than 20 percent of the piers exceed 40 inches (five blocks) high.

All blocks shall be set with the cores placed vertically.

A manufactured/mobile home shall have an approved skirting around its entire perimeter. The wood of the skirting shall be at least three inches from the ground, unless it is pressure-treated wood. Metal fasteners shall be galvanized, stainless steel, or other corrosion-resistant materials. Ferrous metal members in contact with the earth, other than those that are galvanized or stainless steel, shall be coated with an asphaltic emulsion.

A manufactured/mobile home that is installed on a nonrecessed site and has metal skirting shall have ventilation openings with a net area of at least one and one-half square inches per lineal foot. A manufactured/mobile home that has been installed on a recessed site shall have ventilation openings in the foundation fascia with a net area of at least one and one-half square feet for each 25 lineal feet of fascia. The openings shall be designed to provide cross ventilation on at least two approximate opposite sides of the manufactured/mobile home. The installer shall locate the openings as close to the corners of the manufactured/mobile home as practical and shall cover openings with corrosion-resistant wire mesh or louvers.

Dryer vents and hot water tank pressure relief valves shall be exhausted on the exterior of the skirting. The skirting for each section of the manufactured/mobile home shall have an opening of at least 18 inches by 24 inches with a cover of metal or pressure-treated wood to allow access to the crawl space. The skirting must be installed within six months of the placement of the manufactured/mobile home.

Components of the anchoring system shall have a resistance to weather deterioration that is at least equivalent to that of zinc coating that is not less than 0.3 ounces per square foot of coated surface. Cut edges of zinc-coated strapping do not need to be coated.

An installer shall install, preload, and adjust a ground anchor in accordance with the anchor manufacturer's instructions. The installer must supply a copy of the instructions to the building inspection division. A ground anchor, when installed, must be able to resist a working load of 3,150 pounds in the direction of the tie, plus a 50 percent overload (4,725 pounds total) without failure.

Failure occurs if the point of connection of a vertical tie to an anchor is withdrawn more than two inches at 3,150 pounds or point of connection of a diagonal tie is moved more than four inches horizontally when the load of 3,150 pounds is applied at 45 degrees from the horizontal. Sound anchors shall be marked with the manufacturer's identification and model number in a location that is visible after the anchor is installed. The manufacturer of a ground anchor must provide instructions with each anchor that specify the kinds of soil for which the anchor is suitable.

If concrete slabs or continuous footings are used to transfer the anchoring loads to the ground, the following requirements apply:

Ties shall be a cable, strapping or other approved materials. Ties shall be fastened to ground anchors and drawn tight with turnbuckles, yoke fasteners or other approved tensioning devices. Tension devices shall end in cleaves, forged, or welded eyes. Hook ends are not permitted. Tension devices shall be designed to prevent self-disconnection if the tie becomes slack. Cable tie eyes shall be secured with two U-bolt cable clamps, or an approved equivalent. Tie materials must resist a working load of 3,150 pounds with no more than two percent elongation and must withstand a 50 percent overload (4,725 pounds total). Ties shall connect the ground anchor to the main frame longitudinal member. Ties may not connect to steel outrigger beams that fasten to the main frame unless the manufacturer's installation instructions specifically approve the connection. Diagonal ties must lie at least 40 degrees from vertical. Vertical ties must be substantially vertical. If a vertical tie is not substantially vertical, the anchor must be placed outside of the tie's connection to the main frame. A cable frame tie shall be connected to the main frame by a five-eighths-inch drop forged closed eye bolt through a hole drilled in the center of the I-beam web, or by an approved alternative. Installers shall reinforce the web, if necessary, to maintain the strength of the I-beam. The installer shall space the ties as evenly as practical and shall locate a tie within four feet of each end of the manufactured/mobile home.

The installer may attach two or more ties at each detached corner of the clerestory roof and of add-on sections of expandable manufactured/mobile homes. At a minimum, the installer shall install ties according to the manufacturer's installation instructions. Multiple section manufactured homes require only diagonal ties.