Gravel Foundation Recommended for the Storage Sheds
Alan's Factory Outlet Recommends a Gravel Foundation for the Storage Sheds
10x20 a-frame wood storage sheds delivered on a gravel base that was recessed on the one end. The customer framed timbers around the base to help keep the gravel inside. We recommend making the gravel base 2' wider and 2' longer than the size of the shed you get giving you 1' on both sides and ends to help prevent dirt from splashing up on the sidewalls of the building. We recommend a 4" to 6" gravel base of either 3/4" stone also called 57's by some or crusher run. If I had a choice I would go with the 6" deep gravel pad. The recessed pad is not necessary but optional. You could place 6" of gravel down and get 6"x6" and frame out around the perimeter of the shed.
Which stone should I use 3/4" or crusher run?
This kind of depends on whether or not the shed will be located in a wet area if so you may want to consider going with the 3/4" blue stone as it will provide additional drainage benefits over the crusher run. One advantage of the crusher is that it tends to really pact while and kind of turns it to concrete so to speak, but if the area holds water again that advantage now turns into a disadvantage. In most cases the crusher run will be slightly less money which all things being equal if your shed will be resting in a dry location would work fine, but this will kind of depend on your personal preference if moisture isn't a factor.
Wouldn't concrete be a better foundation for a shed?
This is a question we get asked occasionally. And yes, there are certain circumstances where you would be better off with a concrete pad but most of the time this would be when your buying a garage to store a vehicle and not a shed for storage of mowers, garden supplies or house hold items which would not need to be placed on a concrete pad. A concrete slab is going to be way more expensive than a gravel pad, but this is not why we would say get a gravel pad. Water will just rest on a concrete pad vs a gravel pad and especially the 3/4" gravel pad which will let water drain right through the foundation helping protect your building. Now all of the Amish built sheds and Amish built garages at Alan's Factory Outlet come with a 40 year pressure treated foundation and that is if you get it with a floor or without a floor. With a floor comes with 4"x4" pressure treated skids and if you go without a floor it will have pressure treated 6"x6" around the outside of the structure. So water in the short run will not be a problem however if the building is sitting in water most of the time I doubt very seriously you will get 40 years you'll be lucky if you get 20 years and that may be a little too optimistic depending how often it is resting in water.
If your planing on getting a garage we would recommend going with a cement slab in those cases.
Another option to help the gravel pad and this is more so for larger storage buildings would be to add concrete pier below the frost line which varies from location to location depending on the county codes and than fill it in with gravel between and flush up to the top of the pier. If your going to place the piers in the ground please contact us and let us know what size shed or garage your getting so we can let you know the exact location of the pressure treated 4"x4" foundation skids.
What if it is not level?
The foundation needs to be level for the doors to open and shut properly. We do not level the sheds or garages so you will need to make sure that you either check to see that it is level with a bubble string level or with a transit level. You will want to make sure it is level from front to back, side to side and from corner to corner. This is probably the most overlooked issue as many people will just kind of look it over with the eye and think looks pretty level without checking to see and true some people are really blessed with the gift of having a eye for that kind of stuff and some people have a good feel for seeing that it is level because they have a lot of experience with grading and leveling, but there are some me included that eye ball level it and just visit my display lot and you will see first hand I have a couple of display sheds that I didn't plan on it but I now can first hand use as a bad pad example from the stand point of not being level and when you open or shut them the doors kind of rub either the top or bottom a little.
What if I want to save money and just put the shed down on blocks?
We do not recommend putting the sheds on blocks due to setting issues and lack of support the full length of the structure on all of the foundation skids. Also we do not carry blocks on the delivery trailer so from that stand point we do not block the sheds. However if you insist that you want your shed on blocks and if your shed is 10x20 size or smaller and if you provide the blocks and have them laid out prior to our arrival. (You will need to request a sketch of the location of the runners depending on the size shed you get.) We will place the shed on the blocks however they will need to be placed level so the doors open and shut properly.
It is also worth noting that the storage sheds are built with pressure treated 4"x4" runners and than on top of that are 2"x4" floor joist upright and on top of that is a 5/8" plywood floor so the top of the floor is over 7" off of the ground which provides plenty of air flow under the shed so there is really no need to place it on blocks especially if you have down 6" of gravel than the floor is technically over 1' off of the water/dirt ground.
The most important thing for a storage shed or garage just like a house is make sure it is built on a strong foundation.