How, When and Why to Anchor a Shed
I’ve been building sheds for a long time, and one of the most overlooked aspects is anchoring it well. Anchoring a shed is viewed by some as going above-and-beyond, but I think it is important for nearly every shed.
Why should you anchor a shed?
Simply said, anchoring a shed in place increases the stability of the structure. When your shed is anchored the structure and the contents are less likely to be damaged during storms or extreme climate changes.
I have seen sheds that nobody thought would move an inch get repositioned by a strong storm or shifting ground. In the worst case scenario, a lightweight shed can become flying debris in a tornado. It can be bad, but the good news is just a few anchors will make it safer.
The main reasons to anchor your shed are:
- Increased safety for the structure and the contents during high winds.
- Increased safety for the structure and the contents during thunderstorms.
- Anchors ensure that your shed stays where you want it.
- You can lower your property insurance by installing anchors.
- Many manufacturers require sheds to be anchored under their warranty terms and conditions.
- Sheds that are financed through banks or financial institutions may be required to be anchored in place.
- Cable anchors can be used on a variety of shed types and placed on the structure in several different configurations.
What size sheds need to be anchored?
Manufacturers recommend that ALL sheds be anchored. Larger sheds are typically placed on poured concrete foundations and the framework of the sheds is anchored during construction. These larger structures and foundations are considered to be permanent.
Smaller garden sheds and backyard storage sheds are often built as portable buildings and moved onto the property after construction, or they may come as a kit and be installed as a DIY project. Anchoring is a security measure that all shed owners should take.
The bottom line, in my opinion, all sheds should be anchored. It is just that larger ones are typically anchored as a natural part of the building process.
What materials are best for anchoring a shed?
There are several different methods of anchoring a shed. The foundation the shed is placed on, and the materials and size of the shed will play a big role in determining what type of anchors you will need to use to secure your shed.
The most commonly used anchors are:
- Metal – great if you go deep enough into the ground.
- Concrete – which can be used with other materials such as a cable.
The most common styles of anchors are:
- Ground or penetrating anchors – these can be auger-style that are relatively easy for DIY
- A combination of ground anchors and cables or straps
- Mobile home tie-downs.
What steps are involved in anchoring a shed?
The steps involved in anchoring a shed are going to be slightly different according to the type of shed you have and the foundation you are anchoring it to.
Anchoring sheds without concrete foundations
There is more than one method of establishing a secure anchor system on a shed that is not being placed on a concrete foundation.
You have the options of:
- Using a cable that is wrapped around the ground frame and then attaching the cable to a penetrating anchor.
- Putting a cable over a structure member and then attaching the ends of the cable to a penetrating anchor.
- Choose extra large penetrating anchors and use them in place of footings under the structure.
- Attaching an L bracket to the shed exterior and then attaching the other part of the bracket to a ground anchor.
Ground anchors look like they are oversized screws. You have to screw the anchor into the ground using a drill or you can go old school and manually twist the anchor into the ground using a stiff rod inserted in the top portion of the anchor. I highly suggest the drill method for less labor and less time.
Once the ground anchor is in place it has to be attached to the building using brackets, cables, or straps.
If you are using steel cables you need to measure the length of cable that you will need, make sure you leave ample amounts of cable so you can crimp the ends once they are attached to the top of the ground anchor.
Anchoring sheds with concrete slabs
Anchoring a shed to a concrete slab as your shed floor is far easier than anchoring one to other types of foundations. All you need to complete this project is anchor bolts and lag screws or carriage bolts.
- Drill a hole into the concrete to insert the bolts or screws into.
- Drill a hole into the bottom slots on your bracket.
- Place the bolts through the bracket holes and into the holes drilled in the concrete.
- Use a ratchet or crescent wrench and tighten the bolts in place.
- Use a screw to attach the upper section of the bracket to the framing structure of your building.
- Use a hacksaw to trim off the bolts if they protrude too far out of the concrete.
Do’s and Dont’s to Remember When Anchoring Sheds
There are a few things I have learned from experience that you should or should not do when anchoring your shed. Remember not to skimp on this step. Anchoring might be what keeps that expensive shed from toppling over!
- Check the rules and restrictions for the city, county or subdivision you live in before you choose which anchoring system to use on your shed.
- Do not skip anchoring if you live in an area that is threatened by high winds, high water, frequent thunderstorms, hurricanes, or extreme freezing temperatures.
- When deciding how many anchors you need to use the typical formula is to space the anchors as far apart as they are deep in the ground. If your anchor penetrates 18” then space them 18” apart.
- To get the most secure hold it is best to use an anchor that penetrates the ground a minimum of two feet
- Do not anchor a shed to pavers if the shed is in an area that is prone to high wind situations.
You can take the steel cable that you are going to use to attach a shed to a ground anchor and toss the cable over the entire building, then attach each end to an anchor. This is considered to be one of the most secure methods of anchoring a small garden shed.
Check Your Codes
The method and materials you use for anchoring your shed might vary from city to city, so be sure to check your local codes and anchor to those specifications. I’ve had experiences where the exact same shed needs to be anchored in different ways (or doesn’t need to be anchored at all, but I still did) based on the municipal codes for sheds. It should be a very quick check now that virtually all city codes are online.