How to Protect Mobile Homes From High Winds
An unanchored mobile home can be turned over at wind speeds as low as 40 to 50 miles per hour. Mobile homes without proper tie-downs can be turned over in even a strong thunderstorm. If you are in an area vulnerable to hurricanes or tornadoes, tying down your mobile home is essential. Proper tie-downs can increase the wind resistance of the structure enough to allow it to survive wind gusts higher than 70 miles per hour.
Level the mobile home. Hire a foundation leveler to do it, or rent some house jacks and long spirit level and add or remove shims between the concrete support blocks and the frame of the house. Once the anchors are in place, leveling becomes a more complicated and expensive procedure.
Check the wind zone and tie-down charts and compare them with the size of your mobile home. See the Resources link on this page to compare the charts to determine the number of tie-downs you will need to safely secure your home.
Hire a building inspector or engineer to determine your soil type. Talk to the company that you buy your tie-down anchors from to determine what type of anchors you will need to install. You will need strong anchors because you will be attaching them to both the frame underneath the mobile home and to over-the-top straps. If attaching anchors to a concrete pad, make sure the pad is at least 4 inches thick.
Locate all buried pipes and lines so that you don't cut something when you install the anchors. Mark where the lines pass under the mobile home to help you place the anchors safely.
Buy the anchors, tie-down straps, hookups and tensioning devices. Make certain the system you select is certified to at least 4,725 pounds total capacity.
Place the top tie-down straps over the roof. Locate the roof rafters on top of the home. You will need to position the tie-down straps directly over the rafters for strength. Make sure the strap doesn't pass over doors and windows. Buy roof protectors from the tie-down supplier. Place the roof protectors over the edges of the roof where the straps pass over the top and position the tie-down straps. This prevents damage to the edge of the roof.
Install the tie-down anchors following the manufacturer's installation instructions. It's better to hire someone to do this work since a strong anchor point is critical to a correct installation. Follow instructions carefully to ensure the anchor has the manufacturer's rated pull down strength. Be sure the installer sets the anchor at the correct angle. If you have a metal stabilization device installed to keep the anchor from moving sideways, the anchor can be installed vertically. A 10-inch diameter concrete collar, 18 inches deep can also be poured around the top of the anchor to properly stabilize a vertical anchor. Diagonal frame tie-downs require an anchor set at an angle of at least 40 degrees.
Adjust the tension of the top tie-down straps. Work from side to side so the straps pull evenly. If you do all the straps on one side, you can damage the roof by creating an asymetrical pressure on the rafters and frame of the house.
Attach the frame tie-downs one at a time. Again, alternate tensioning the tie-downs from side to side so the pressure from the tie-downs is distributed evenly to avoid twisting the frame.
Things You Will Need
- House jack
- Shims and hammer
- Mobile home tie-down anchors
- Tie-down straps
- Tensioning device
- Roof protector