How to Install Tie-downs for Manufactured Homes & Sheds

Why tie-downs?
Manufactured homes and sheds must have anchors and tie-downs to keep them in place during high winds. Compared to site-
built homes, manufactured homes and sheds are relatively lightweight. They have flat sides and ends, and they are built on
frames rather than foundations. Almost all manufactured homes and
sheds are elevated, situated on t
op of some sort of pier or
foundation system. Wind can get under the homes and lift them up. In addition, the wind passing over the top of your
manufactured home can create an uplift force.
To resist wind forces, you need two different types of tie-downs.
In older homes, a vertical or over-the-top tie-down is needed
to compensate for the uplift force. A diagonal or frame tie-down is needed to compensate for both lateral and uplift forces.
Singlewide manufactured homes need both types of tie-downs. Doublewide homes only need the diagonal ties
Tie Down Requirements for manufactured homes

• Singlewide manufactured homes require both diagonal and vertical ties.
• Doublewide manufactured homes require only diagonal ties.
• To determine the length, do not include the draw bar.
• Numbers based on minimum working load per anchor of
3,150 pounds, with a 50% overload of 4,725 pounds.
• Diagonal ties must deviate at least
40 degrees from a vertical direction.
• If your home has special site considerations, a registered professional engineer or architect can devise an alternate anchoring
system.
Anchoring system components
Types of tie-downs.
The type of tie-down you select usually depends
on when your manufactured home was built. Older homes
often have exposed over-the-top tie-downs. This is an effective syste
m, but it does detract from the appearance of your house.
The straps are placed over the siding and roof. Until recent
years, most manufactured homes
came equipped with concealed
over-the-top tie-downs. These straps are located just under the
exterior siding and metal roof. The end of the strap hangs out
under the manufactured home. Newer model
homes might not have any type of over-t
he-top tie-down. Because of increased
structural strength of manufactured homes, these models are secured with anchoring straps attached to the home’s steel frame
rails, called frame anchors. Doublewides
are also secured with frame anchors.
Types of anchors.
You’ll find anchors available for different types of soil
conditions, including concrete slab. Auger anchors have been designed for both hardsoil and soft soil. Rock anchors or drive anchors allow attachment to a rock or coral base. This type of anchor is also pinned to
the ground with crossing steel stakes. If you will be pouring a concrete base, you can install a concrete anchor first.
You need to know your soil type to select the right
anchor.
Soil classifications
usually include: rock/hard pan, heavy, sandy gravel,
heavy sand, silty gravel,
clayey gravel, clay, silty clay, clayey
silt, uncommitted
fill or peat/organic
clay.
(ll)
Whatever type of anchors you select, care fully follow the installation instructions.
Auger anchors (screw-in anchors) can be installed
manually by inserting a metal bar through the top of the anchor for added leverage or with a machine designed for this purpose. It’s important to screw this type of anchor in. Do not dig a hole to instal Hook-up and tension device:
The tie-down must be connected to the anchor with a system that allows for adjusting the tension. It must also be weather resistant and strong enough to support as much weight as the anchor and tie-down. If the tie-down is fastened to a ground anchor with a drop-forged turnbuckle, the turnbuckle should be ½ inch or larger galvanized steel. The turnbuckle should have forged or welded eyes, not hook ends.The roof protector. If you have exposed over-the-top tie-downs, you must have some sort
of roof protectors placed under the strap or cable at the edge of the roof. Roof protectors are also called roof brackets, buffers or thimbles. These prevent the tie-down strap or cable from damaging the roof and will prevent the edge of the roof from cutting through the tie-down. Wood blocks
will work, and are better than nothing, but commercial protectors
will do a better job of distributing the pressure of the cable.
Commercial protectors will last longer, too.
Specifications.
Make sure all your anchoring equipment (anchors, turnbuckles, straps, hookups) is capable of resisting an allowable working load of at least 3,150 pounds. The equipment must also be capable of withstanding a 50 percent overload,
4,725 pounds. This also applies to the attachment point on t
he manufactured home. Only use anchoring equipment that is
weather and corrosion resistant. YOU MUST ALIGN EXPOSED OVER-THE-TOP
TIE-DOWNS WITH A ROOF RAFTER TO PREVENT DAMAGING THE ROOF.
Tie-downs can be either cable or strap. If cable is used, it
should be galvanized steel or stainless steel. Minimum diameter size is
3/8 inches for 7 x 7, or ¼ inch for “aircraft” cable, 7 x 19.
If flat steel strapping is used, it must be a minimum of 1-¼ inches wide x
.035 inches thick.
Tie-down and anchor installation
Installing a tie-down and anchoring system is not too complicated for most do-it-yourselfers. It’s wise, however, to seek
experienced help to make sure you are using the proper anchor
for your soil conditions, enough anchors for your wind conditions,
the correct tension on your tie-down, and proper angle for your
frame tie-downs. At the very least you should have a building
inspector or a trained installer check over your finished work.
STEP 1: Level house
Make sure your home is level before anchoring it to the ground.
STEP 2: Check chartsCheck
the wind zone chart
for your location and determine the required number of anchors recommended for your zone. You
should regard this number as the minimum needed for your home.
STEP 3: Determine soil type
Merely looking at the ground under your home isn’t enough. Some
types of anchors need to be installed five feet deep. Talk to a
building inspector to determine your soil type. If you will be attaching your tie-downs to a concrete foundation, make sure it is at least 4 inches thick.
STEP 4: Select anchors
Talk to a supplier or installer for advice.Your soil type will determine the type of anchor.
STEP 5: Select hook-up
Depending on your tie-down system, over-the-top or frame, select the appropriate hook-up and tensioning device. Make sure the
entire system is certified to a 4,725 pound capacity.
STEP 6: Locate wires/cables Mark the location of your electric, cable, gas, water, sewer and phone lines on the ground before you install anchors. Make sure you have located everything prior to digging.
STEP 7: Position over-the-top tie-downs
If you are installing an exposed over-the-top
tie-down, the strap or cable should be positioned over a roof rafter. Protect the edges of your roof with a roof protector of some type. Make
sure the strap or cable does not cover a window or door.
STEP 8: Install anchor
You’ll find specific installation instructions with your
anchor. Follow them carefully.
For a vertical tie-down, the anchor is installed vertically.
For a frame/diagonal tie-down, the anchor can be installed to the same angle as the tie-down. This angle should be at least 40 degrees.
The anchor can be installed vertically
if you also install a stabilization device to keep the anchor from moving sideways. A metal stabilization device can be attached to the t
op of the anchor and buried in the ground.
Another option is to pour a concrete collar around the top
of the anchor. The collar should be at least 10 inches in diameter and 18 inches deep.
STEP 9: Adjust tension
Alternating from side to side,
adjust your tie-downs to the appropriate tension. Don’t do one side of your house and then the other.
REMEMBER:
Anchoring and tie-down systems vary greatly. It’s important for you to contact the local building inspector for regulations regarding
anchoring and blocking installation in your community. Regulations
vary considerably from one community to the next. In some
states, tie-downs aren’t required.
In other states, tie-downs are stringently regulated and inspected.
To be tied down safely, find out from your local manufactured
home association or building inspector how many tie-downs and
anchors you need for your wind and soil conditions. The cost of installing additional tie-downs and anchors is small compared to
the potential cost of wind damage to a manufactured home that was not properly tied down.

Definitions and Scope of a Home Inspection

1.1.  A general home inspection is a non-invasive, visual examination of the accessible areas of a residential property (as delineated below), performed for a fee, which is designed to identify defects within specific systems and components defined by these Standards that are both observed and deemed material by the inspector.  The scope of work may be modified by the Client and Inspector prior to the inspection process.

  1.                                                        I.            The general home inspection is based on the observations made on the date of the inspection, and not a prediction of future conditions.
  2.                                                     II.            The general home inspection will not reveal every issue that exists or ever could exist, but only those material defects observed on the date of the inspection.

1.2.  A material defect is a specific issue with a system or component of a residential property that may have a significant, adverse impact on the value of the property, or that poses an unreasonable risk to people.  The fact that a system or component is near, at or beyond the end of its normal useful life is not, in itself, a material defect.

1.3.  A general home inspection report shall identify, in written format, defects within specific systems and components defined by these Standards that are both observed and deemed material by the inspector.  Inspection reports may include additional comments and recommendations.

 

2. Limitations, Exceptions & Exclusions

2.1. Limitations:

  1.                                                        I.            An inspection is not technically exhaustive.
  2.                                                     II.            An inspection will not identify concealed or latent defects.
  3.                                                  III.            An inspection will not deal with aesthetic concerns or what could be deemed matters of taste, cosmetic defects, etc.
  4.                                                  IV.            An inspection will not determine the suitability of the property for any use.
  5.                                                     V.            An inspection does not determine the market value of the property or its marketability.
  6.                                                  VI.            An inspection does not determine the insurability of the property.
  7.                                               VII.            An inspection does not determine the advisability or inadvisability of the purchase of the inspected property.
  8.                                            VIII.            An inspection does not determine the life expectancy of the property or any components or systems therein.
  9.                                                  IX.            An inspection does not include items not permanently installed.
  10.                                                     X.            These Standards of Practice apply only to properties with four or fewer residential units.

2.2. Exclusions:

I. The inspector is not required to determine:

  1. property boundary lines or encroachments.
  2. the condition of any component or system that is not readily accessible.
  3. the service life expectancy of any component or system.
  4. the size, capacity, BTU, performance or efficiency of any component or system.
  5. the cause or reason of any condition.
  6. the cause for the need of correction, repair or replacement of any system or component.
  7. future conditions.
  8. compliance with codes or regulations.
  9. the presence of evidence of rodents, birds, animals, insects, or other pests.
  10. the presence of mold, mildew or fungus.
  11. the presence of airborne hazards, including radon.
  12. the air quality.
  13. the existence of environmental hazards, including lead paint, asbestos or toxic drywall.
  14. the existence of electromagnetic fields.
  15. any hazardous waste conditions.
  16. any manufacturers’ recalls or conformance with manufacturer installation, or any information included for consumer protection purposes.
  17. acoustical properties.
  18. correction, replacement or repair cost estimates.
  19. estimates of the cost to operate any given system.

II. The inspector is not required to operate:

  1. any system that is shut down.
  2. any system that does not function properly.
  3. or evaluate low-voltage electrical systems such as, but not limited to:

    1. phone lines;
    2. cable lines;
    3. satellite dishes;
    4. antennae;
    5. lights; or
    6. remote controls.

  4. any system that does not turn on with the use of normal operating controls.
  5. any shut-off valves or manual stop valves.
  6. any electrical disconnect or over-current protection devices.
  7. any alarm systems.
  8. moisture meters, gas detectors or similar equipment.

III. The inspector is not required to:

  1. move any personal items or other obstructions, such as, but not limited to:  throw rugs, carpeting, wall coverings, furniture, ceiling tiles, window coverings, equipment, plants, ice, debris, snow, water, dirt, pets, or anything else that might restrict the visual inspection.
  2. dismantle, open or uncover any system or component.
  3. enter or access any area that may, in the opinion of the inspector, be unsafe.
  4. enter crawlspaces or other areas that may be unsafe or not readily accessible.
  5. inspect underground items, such as, but not limited to: lawn-irrigation systems, underground storage tanks or other indications of their presence, whether abandoned or actively used.
  6. do anything which may, in the inspector’s opinion, be unsafe or dangerous to the inspector or others, or damage property, such as, but not limited to:  walking on roof surfaces, climbing ladders, entering attic spaces, or negotiating with pets.
  7. inspect decorative items.
  8. inspect common elements or areas in multi-unit housing.
  9. inspect intercoms, speaker systems or security systems.
  10. offer guarantees or warranties.
  11. offer or perform any engineering services.
  12. offer or perform any trade or professional service other than general home inspection.
  13. research the history of the property, or report on its potential for alteration, modification, extendibility or suitability for a specific or proposed use for occupancy.
  14. determine the age of construction or installation of any system, structure or component of a building, or differentiate between original construction and subsequent additions, improvements, renovations or replacements.
  15. determine the insurability of a property.
  16. perform or offer Phase 1 or environmental audits.
  17. inspect any system or component that is not included in these Standards.
  18. (From the Internachi Home Inspectors Scope of Inspections)