The following information is designed to assist with the installation of your mobile or manufactured home, and to ensure a successful inspection. This information is only a guide, complete and in-depth instruction can be had by contacting CSA @ 1-800-463-6727 (or see "links") and acquiring their publication Z240.10.1-94 Site Preparation, Foundation , and Anchorage of Mobile Homes. For the purpose of this document, a mobile or manufactured home is defined as a transportable single or multiple section, single family dwelling conforming to the CSA Z-240 or A-277 standards at the time of manufacturer.

IMPORTANT: Check with local authority with regards to local requirements and permits

INDEX

SITE PREPARATION FOUNDATION ANCHORING SKIRTING

SITE PREPARATION

The topsoil and vegetation must be removed from the area where the mobile home is to be placed. The excavation area should extend a minimum of 6" outside the perimeter of the mobile home. After the excavation is complete, the area must be filled with an inorganic material such as gravel to a level above the surrounding grade. The fill must be sloped away from the center of the mobile home towards the sides at a minimum slope of 2%. This will prevent the accumulation of water underneath the mobile home.

A suitable ground cover such as concrete, polyethylene, or type 'S" roll roofing should be placed

on top of the fill and extending to a minimum of 6" past the perimeter of the mobile home. Where polyethylene or type 'S" roil roofing are used, overlaps must be a minimum of .4". This cover prevents the upward migration of moisture end allows the crawlspace to remain dry. The distance between the top of the ground cover and the underside of the mobile (bottom from floor joists) must be a minimum of 24". in mobile homes designed with a sunken portion (example: sunken living room). the clearance between the bottom of the joists in the sunken portion and the ground cover shall be a minimum of 12".

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FOUNDATIONS

All mobile homes must be supported off their running gear (wheels apply to older homes - new homes no longer come with running gear (Canada). This may be accomplished through the use of piles, piers, or cribbing (blocking). All manufacturers provide instructions for the spacing of these foundation methods, however, if manufacturers instructions are not available, a spacing of 8 feet is recommended and in no case should spacing exceed 10 feet

Pile Foundations

Piles used to support mobile homes are required to be designed for existing soil conditions. See Table A below

Recommended footing size

Table A                                                                    Pier Spacing

Type of Soil                                                   [6']            [8']            [10']

Soft Clay, loose sand, loose gravel                 22"²         25"²           30"²

Firm clay, compact silt                                   16"²          18"²           20"²

Compact sand, compact gravel, stiff clay        12"²         14"²            15"²

Shale, rock                                                    10"²         10"²            12"²

Pier Foundations

When using a pier foundation, the footing of the pier should be built below the frost depth and in no case shall the top of the footing be closer than 4ft. to grade. To determine the size of footings to be used refer to Table A above. When footings are installed in soil not identified in Table A, the design must be in conformance with accepted. engineering practices. The concrete piers supported by the footing shall be a minimum of 8' diameter if circular, or 8" X 8" if square. A minimum of four ½ inch-reinforcing bars must be used in the construction of the pier extending from the footing into the column.

Wood Crib Foundations

Wood cribs shall be placed on a concrete or pressure treated wood footing as detailed on the wood crib detail Materials used to build a wood crib must consist of good quality lumber arranged in such a manner that each layer rests at a right angle to the layer below. Each layer must be securely nailed. A wood crib must at reach a height of more than 1 and 1/2 times its width.
(Diagram)

SCREW IN AUGER FOOTING
Screw in AUGER footings are becoming popular. Augers are screwed in where you would normally put your foundation. The center of the Auger stem is hollow; a sleeve is inserted into this and adjusted accordingly and once the home is level the sleeve is welded to the Auger stem and to the home's frame. Price for installation vary but runs anywhere from $100 to $150 per Auger.

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ANCHORING

Mobile homes are required to be anchored to the ground through the use of ground anchors or the foundation unless it can be demonstrated by calculation or local experience that ground anchorage is not required. Information for calculation purposes can be found In Part 4 of the National Building Code of Canada. The use of anchors greatly reduces the cost of the insurance and therefore should be considered even if you do not fall into the above mention parameters. Read article " wind force on mobile homes"

(Diagram)

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SKIRTING

Skirting should be installed to prevent debris and cold air from accumulating under the home. The skirting must be installed in a manner which allows for movement caused by setting and frost action. When skirting is used, allowance for ventilation must also be made. Accordingly, screened louvers or grills must be installed allowing one square foot of open area for each 500 sq. ft. of floor area. Ventilation grills shall be uniformly spaced on apposing ends of the home. A minimum of one access panel must be provided in the skirting to allow for inspection and maintenance of the underside of the home. The access panel must be a minimum of 24" x 24" and it is recommended that this panel be located as close as practical to the sewer and water connection.

(Diagram)

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