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How to Lift a Sunken Shed Foundation?

Actually, when leveling a shed, most of the time you won’t be lifting the actual foundation, but lifting the shed off the foundation. The most popular shed foundation is gravel. Once your shed is lifted, more gravel can be added to make the shed level again. Of course, trying to lift a concrete pad can turn into a nightmare trying to keep the concrete from cracking, and raising concrete piers poured into the ground is out.

What you will usually do is lift the shed on the low side and use something to keep it raised so that the foundation is leveled, or the shed is propped up with something. This could be extra gravel, blocks or shims, depending on the type of foundation and how far the shed needs to be leveled.

How Do You Level a Sunken Shed?

You’ll have to assess the size of the shed and the foundation type in order to find out what tools you will need. First, take everything out of the shed. You don’t want any extra weight in the shed or anything sliding around or falling off shelves. Using scrap lumber as cross bracing across window and door frames will help keep the frames square. If they get off-kilter during the raising, it may affect how the window and door work.

Using jacks is the usual method for leveling a sunken shed. Make sure your jacks have a rather large, solid base underneath them or the jacks will sink when you start trying to raise the shed. You’ll probably have to dig under the places you want to place the jacks to get underneath the frame. With a small shed, you can use a car jack.

For larger sheds, hydraulic jacks or moving jacks are useful. Using long sections of 2×6 lumber as temporary bracing can keep your shed raised enough for you to work on a more permanent foundation lift. You can use concrete blocks under the low side to level it out. If you have your shed set on a gravel foundation, you can just add gravel and tamp it down before lowering the shed. You may find my article How Do I Keep My Shed from Sinking? while your repairing your shed.

How Do You Straighten a Leaning Shed?

You can use a pair of ratcheting cable hoists or a winch system to straighten out a shed. Pound a couple of stakes into the ground parallel with each corner on the side that is leaning away from you. You can also use a tree or utility pole as an anchor. Drill a pilot hole into both corner posts at the same height on both.

These holes can be put into the siding if it is solid enough to hold the strain. Thread a half-inch diameter screw eye into the hole. Use these to attach the cable hoists to the stakes. Ratchet in the cable hoists a little at the time, alternating sides until the shed straightens. Take it slow – if you ratchet it in too quickly or too much on one side, you risk having things coming loose.

Use a level to find out when the shed is straight. While the shed is still held by the cables, go inside and install some corner braces. Use 2x4s or 2x6s. These braces should go from the top plate to the bottom frame and cross at least four studs. Once the braces are installed, you can remove the cable hoists.

A winch can also be used. Pulling an inch at a time and pause between pulls. When level, install your cross bracing. Cross bracing is important, as it will keep the shed from leaning again and add stability. Read my article How High Should a Shed Be Off the Ground? to find out how to keep your shed off the ground.

Can You Use a Car Jack to Lift a Shed?

Many people use a car jack to lift a shed. It all depends on the size of the shed and its weight. For instance, a shed with wood siding will weigh more than a plastic prefab shed of the same size. For most sheds, you’ll need two jacks, one for each end of the low side. Jack stands will help add stability once you raise up each side.

Once you start, if it looks as though there may be doubts as to whether the car jack is enough for the job, stop and get a hydraulic jack. You don’t want to risk the car jack suddenly letting go when someone’s hand is underneath the shed placing shims or blocks.

How Do You Lift a Shed by Hand?

If you don’t have jacks available, a strong rod for a lever and some concrete blocks can raise your shed. PVC or metal piping can be used as your lever. You’ll need someone to help by sliding the required shims or two-inch blocks of lumber for a higher lift underneath the side of the shed base once you lift it.

Depending on how far you need to lift one side, you may use multiple blocks to hold the shed in place until you can get something more stable and permanent underneath.

Do You Need a Foundation for a Shed?

A shed really needs some kind of foundation. While some argue that a shed can be placed right on the ground as long as pressure-treated lumber is used for the joists or skids, pressure-treated lumber is not waterproof. The treatment just delays and resists moisture damage but it will eventually deteriorate.

Besides this, the soil does shift from time to time with heavy rainfall or soil condition and type. If you just want a small shed and don’t want to invest in a lot of expense or work, a gravel foundation will provide drainage and keep your shed level.

Even all plastic sheds need some kind of foundation to keep everything level. If it isn’t level, you’ll have a tough time assembling the shed panels, as they may not fit together as easily as designed. In addition, strain will be added to connections as they would to the connections of any shed not on a level, stable base.

Nails can start to pull out of the framing or studs, and eventually, small spaces can be formed in the siding. A foundation will also keep your shed and its frame farther away from any insects that might be able to damage your wood framing and make it harder for mice and rats to get in.

There are many types of foundation materials you can use for a shed. The most popular is the gravel base. It is also one of the most economical and easiest to install. Measure off the space of your shed and add a foot all the way around. This will allow for extra drainage around the shed, especially water running off the roof.

Dig down around the perimeter to start setting your foundation boards. Usually, 4x6s set on edge work well. They should be pressure-treated and rated as GC for ground contact. Make sure they are all level. You can build up the foundation boards in more board layers. This is a good way to even out a slope. Use 4″ exterior screws to fasten.

Once you get that done, landscape fabric or vapor barrier will go down next to prevent any weeds from poking up into the gravel. Vapor or moisture barriers also help with drainage. Choosing the gravel is important. Crushed, clean stone 3/4-inch size is the desired type, as it has angular edges rather than smooth or rounded edges and will tamp down more firmly.

Fill your frame a couple of inches at a time and tamp down, making sure to keep the gravel surface level. Waiting until you fill the space with six inches of gravel to tamp it down is a lot harder than tamping at intervals.

There are plastic bases for sheds that are made in various grid patterns. They can support a surprising amount of weight. They usually come in squares that are assembled together to create the desired shape and size. Installing one over a gravel base will keep drainage good under the shed and help prevent erosion.

Concrete paving stones make a good base, especially the larger ones. Start by digging out an inch or two of soil. Make sure the area is level and the soil is tamped down firmly throughout. Fill your space with gravel and tamp it down also. Then you can lay in your pavers and make them level.

Pier or deck blocks are concrete blocks that are a good foundation, and are especially helpful in places that get a lot of rainfall, as they allow you to keep your shed raised above the ground and above running water. The blocks are smaller than the traditional concrete blocks and are made to have lumber attached to them.

Pier blocks come with brackets that attach to various lumber thicknesses. You can attach your shed bottom frame to them with screws. Deck blocks have channels in them for the framing lumber to fit into.

A good idea is to set these blocks on gravel to facilitate drainage. Dig holes where you will fit your blocks and fill them to ground level with the gravel. Both kinds of blocks should be spaced around three to four feet apart. Check with your local building authority as to frost conditions in your area, as frost heave may make your blocks shift. If you need some help in deciding what foundation to use read my article What’s The Best Shed Foundation Option For You?

How to Level a Shed on a Concrete Slab?

If your shed is built on an existing slab and becomes off level, straightening it out usually involves lifting the lower side of the shed and inserting shims between your skids or shed base and the concrete slab. Shims can be made of pressure-treated lumber or plastic.

If the slab is causing the problem, lifting the shed and using shims is much easier than trying to level the slab itself. In fact, if the slab is large or is thin, it’s almost impossible to raise one without something cracking, even if there was rebar or a metal grid inserted into the concrete when it was poured.

If you do want to try raising the slab, the repair needed to level the concrete would be to spread gravel under the low side to level the slab. However, it would be really tough to get that gravel spread out level and tamped down solidly under a slab raised on one side.

How to Lift the Corner of a Sinking Shed?

Even if just one corner seems to become lower due to water pooling or flowing at that particular spot, you don’t want to try raising a shed diagonally so that it rests on one corner. Use your jack or lever system near the corner you want to raise. You’ll actually be raising up one whole side.

How to Lift a Sunken Shed Foundation?

The foundation isn’t actually what you want to raise in most cases. Whether the foundation is a slab, gravel or concrete piers, what you really will be doing is lifting the shed from the foundation to permit putting props under the low side. The exceptions are when the foundation is made of pier or deck blocks or a plastic shed base. These can be lifted once the shed is raised on the low side and gravel filled in underneath to level the foundation.

How Do I Know If My Shed is Not Level?

You can use a carpenter’s level inside the shed if you bought a property that already has an existing shed to check on its level condition. If you built the shed or bought a prefab shed, you would have made sure that it was level to start with, but you should check it periodically to make sure it stays level. Watch what happens when you have heavy rain.

If water flows around one corner every time or water tends to pool near one corner or side, the water may cause changes in the soil beneath and eventually affect the level of the shed.


Sometimes conditions under the topsoil can change or shift, causing sinking in an area. Keeping an eye on these conditions will let you know that the level needs to be checked. The sooner you discover a problem with your shed’s level condition, the sooner you can address it and the less work there will be.