A firm, level base is important to the longevity of your storage shed. In our storage shed buyers guide we discuss site preparation but I am going to go a little more in depth here.

If you don’t feel you can tackle the site preparation you can opt to hire a local landscape contractor.

Crushed Stone Base

The crushed stone base is now the most widely accepted site preparation for sheds under 400 square feet. For over 18 years we have been recommending this type of site preparation and within the past 2 years more and more towns and municipalities have begun to catch on and recommend this type of base to those applying for shed permits.

What you’ll need(for do it yourselfers)

• Roll of string
• Tape measure
• Spade shovel
• Wheelbarrow
• Grading rake or iron rake
• Line level
• 4 stakes
• Eight foot long 2″x4″
• Four foot level
• Crushed stone (amount based on size of shed – chart below)
• Optional – Landscape fabric/weed cloth

Step 1

Add 2 feet to the length of the shed as well as the width.

Next measure the area and place a stake in each corner. Remember to add the 2 feet to the length and width.

To be sure that your layout is square measure diagonally from corner to corner and be sure these distances are equal.

Square your area

Step 2

Starting at the highest corner wrap the string around the bottom of the stake and run it to the lowest stake. Place a line level on the string and pull the string taut. Move the string up and down until the string is level. Wrap the string around the stake at this height. At the lowest point measure from the string to the ground. Add 4 inches to this distance and beginning at the high point dig down to the depth. Excavate the entire area.

Remove the grass and top soil

Step 3

Once the grass and topsoil are removed rake out the area.

Rake out the site

Step 4

Back fill the area with the crushed stone then rake it out so it is level. use the 2″x4″ to check for level. Be sure to check it from front to back as well as side to side. Check for level in several different spots as you rake out the crushed stone.

Completed stone site prep.

Step 5

This is an optional step but watering the stone can help it to compact a little better. The water will wash the finer particles through the stone allowing the crushed rock to settle.

Crushed Stone Base w/Timber frame

What you’ll Need

• Circular saw, chain saw or cutoff saw
• Timbers – I recommend 6″ x 6″ timbers however 4″ x 6″ will work as well. Make sure they are ground contact rated pressure treated. The timbers must be equal to the sum of the four sides of your site. For instance if you are creating a elevated stone pad for a 10′x16′ shed you would first add 2′ to the length and width then add the four sides together. So you would need 60 linear feet of timber (12 +12 + 18 + 18 = 60).
• Depending on how high you will be building your base you will need additional timbers to be used as “dead men”.
• #5 Rebar or similar cut to 4′ lengths. You will need 1 piece of rebar for every 4 feet of your frame.
• Drill (hammer drill recommended) and a 5/8″ drill bit which can reach a depth of 6″ minimum
• Sledge hammer
• Roll of string
• Tape measure
• Spade shovel
• Wheelbarrow
• Grading rake or iron rake
• Line level
• 4 stakes
• Eight foot long 2″x4″
• Four foot level
• Crushed stone (to calculate the amount needed use this chart)

Step 1

Follow steps 1-3 used for the “Crushed Stone base”

Step 2

Place the landscape timbers around the perimeter of the site. Be sure the timbers are level. Drill holes through the timbers every 4 feet and rebar the timbers into place using the 4′ lengths of rebar. For larger bases you may want to add “dead men” which are timbers which run perpendicular to the outer timbers to help keep the from moving however since the outer timbers are set in the ground the dead men are not entirely necessary.

Step 3

With the timbers in place you can now backfill your site with the crushed stone.

A cheap, effective way to create a base for your small storage shed

We recommend a crushed stone base to most of our customers however sometimes it just isn’t worth the time and money. In cases where the shed is very small (under 80 square feet) although a good idea a stone base isn’t always necessary.

If you are thinking of building or buying a shed around this size here is a simple yet effective way to prepare your shed site.

The first and most important thing is to find a level spot in your yard. be sure it is an area that is relatively dry throughout the year.

Second, purchase patio blocks 2″x8″x16″. These can be purchased at most masonry supply stores or garden centers. Most Home Depots also carry them. The number of blocks needed will vary depending on the shed construction (more info below).

Depending on the base of the shed the next steps will vary. If your shed comes fitted with 4″x4″s running perpendicular to the floor joists which will keep it off the ground the blocks are not necessary other than for leveling your shed in which case you should only need 6-8 blocks if your shed is a couple of inches out of level and more if your grade is more than a few inches.

If your shed has 2″x6″ floor joists without any 4″x4″s keeping it off the ground then you need to use the patio blocks to elevate the entire shed. In the event your site is perfectly level then 1 -2 stacked blocks will raise it enough to allow ventilation. In this case I would suggest purchasing about 12 blocks unless the grade is more than 4-6″ out of level in which case I would buy more and return those which you don’t use.

This type of storage shed base can be done AFTER the shed is built or delivered. In most cases, if the shed is being delivered fully assembled or being erected on site by the company you purchased it from the delivery person or installation crew will place your shed on the blocks for you. If you are building it yourself then once you have completed the floor place a 4′ level on it and find the high point. Place 1 patio block on the highest corner then place blocks in the rest of the corners adding blocks as necessary to level the floor.

Once the floor is level add blocks and shims every 3′-4′ in order to support the building. You should also support the center of the shed.

Once your base is level and supported finish your shed build.

Once you have completed the shed or the delivery/installation crew is done and gone it is time for some more site work.

In order to protect your shed from splatter from rain run off as well as from weeds and grass growing against it we are going to excavate and area of about 1′ all the way around the shed. Dig down about 6″ in depth and back fill with the crushed stone of your choice. Pea stone is not recommended as it doesn’t compact well and may end up in your lawn. 1″ or under crushed stone or gravel tends to work best as it compacts well. You may also add weed cloth under the stone for added protection.

On sheds with overhangs be sure and measure a foot out from the overhang and not from the floor itself.

That’s it! Your site is complete!