How to Build a Gravel Shed Foundation

[Music] [Music] hi this is James with site preparations LLC today we're going to talk about how to install a gravel shed foundation for your new shed garage or portable building before we get into talking about how to install gravel cheb foundation let's talk a little bit about why you would want to install gravel versus some of the other options that are available for shed foundations so first off gravel is one of the best supporting foundations first yet so compared to shed foundation blocks or concrete blocks which a lot of folks use a gravel foundation provides an even support underneath all parts of your shed so that over time one part or one corner of your shed doesn't begin to sink compared to the rest another reason that gravel is such a good option is that compared to concrete it drains a lot better so with concrete you tend to see water puddles form at times and that can be hard on the on the runners underneath your shed and potentially cause rot and other forms of decay if it's properly installed a gravel foundation will let water drain away much much more quickly and preserve the body of your shed second is the ease of installation with the gravel foundation unlike concrete which is a little higher demand in terms of skill the gravel foundation can be installed by anyone with even intermediate construction experience and you can install it start to finish pretty much using hand tools the final reason that gravel is such a great option is cost compared to concrete a gravel is much more cost effective and it'll still provide an excellent foundation excellent base for your shed for years to come one other thing to think about before we get to installing a gravel shed foundation is where we're gonna put the shed you might already have a spot picked out but if not here's a couple considerations to keep in mind first off you want to think about topography so wearing your property will be a well-drained area that's not gonna collect moisture around your shed where is gonna be a pretty level area because it's too sloped you're gonna have to do a lot more prep work before you can start installing your chef's foundation you don't want to think about an area with undisturbed ground because if the ground has recently been backfilled due to construction or something else there's a chance of your shed settling overtime you also want to think about obstructions that might be in the way so obviously the less stumps or bushes you need to remove the simpler it's gonna be and finally when thinking about topography you want to think about lighting and this is especially important if you're gonna want to be working inside your shed you want to think about natural light and you also want to think about the fact that sunlight will help protect your building from mold from algae from mildew and keep it in good shape for years to come in addition to topography another thing to consider when choosing a shed site is where our utility lines if you cut through a gas line or an electric line while you're installing your shed foundation things are gonna get a lot more complicated you can call 8 1 1 anywhere in the United States to find out exactly where your utility lines are located it's a free service that's available to homeowners so definitely take advantage of it third you want to find out what requirements your local municipality has regarding shed location these could include things like setback how far your shed needs to be from the perimeter of your property footprint how much of your property a shed can cover this is obviously gonna be extra important if you have a smaller size property frost protection if you're in a northern area your local Township or municipality might have requirements as far as the type of footers your shed needs to have so you want to check this before you make a final decision on the type shed foundation that you're installing because it may require a concrete footer under the shed corners in addition to the gravel foundation itself obviously this varies depending on the township so check with your local municipality to see what their requirements are there's also sometimes requirements about anchoring your shut down so make sure that the foundation you choose and the site you choose allows you properly anchor your building down once it's completed the fourth thing to consider is accessibility obviously you don't want to have to go far to your shed to get the things that are stored inside so think through where it's going to be the most convenient when you choose a location for it final thing to consider when choosing a shed location is appearance if you're putting a lot of work into the exterior of your shed or you're paying a lot of money for someone else to build a beautiful shed you want to make sure you get the most value you can so think about the curbside appeal of your property and where the shed will add the most value in that regard now that you're ready to get started on construction it's time to gather the tools that you'll need first off you'll need a tape measure because you can't do construction without a tape measure right second you need marking paint for marking the exact location of the foundation and marking the corners out in preparation for starting digging you want to level a straight level Carpenters level works the best at least four feet long so that you can get a good feeling of the exact level of foundation as you install it you'll need a drill with a half inch auger bit and that bit should be at least 18 inches long so you can drill through all the perimeter and down to the ground so you can stake the foundation perimeter to the ground you'll need a sledgehammer for pounding States you'll need a circular saw for cutting lumber for the perimeter a screw gun can be helpful in addition to the drill but you can also use your drill as a screw gun as well if you need a staple gun will be useful for fastening the weed barrier to the perimeter before you put the gravel in place and of course you need a shovel for moving dirt around you want a rake for smoothing gravel a concrete rate works the best has a flat bottom that lets you spread gravel and smooth it out much easier and then a hand tamper will let you Pat gravel in place you can also really use a wheelbarrow because moving gravel around is gonna be much simpler if you have a good way to transport it finally don't forget to think about personal protective equipment like hearing protection safety glasses and gloves these will help keep you safe as you work in addition to the hand tools that I just mentioned there's also several power tools that if you have access to or it can rent will really speed the process up a laser level will make it much simpler to level the area for your foundation especially if it's on the slope a mini skid steer will help you transport stuff and smooth the dirt and really do the excavation much quicker than if you're only using a hand shell and then finally a power plate compactor will get the gravel much tighter and make that tamping process much quicker than only using a hand tamper once you have the tools together it's time to get the materials for actually building the foundation first off you'll need a lumber to build a perimeter around the foundation here at site preparations LLC we recommend four by six pressure treated ground contact longer you could also use four by four or six by six but we find that four by sixes work the best make sure that it's rated for ground contacts because you don't want it deteriorating as it sits in the ground it's gonna be in constant contact with moisture and so you have to make sure that it's rated for that half inch rebar is what we use to stake down the perimeter of our sheykh foundations and that's what we recommend for you as well you can either buy it cut in two foot pieces out of place like Home Depot or you can cut it yourself with a grinder or a hacksaw 4-inch exterior screws are what we use to fasten the perimeter corners together yes something that's hot dipped galvanized or better in its exterior coating because you don't want the screws rusting out and the perimeter starting to weaken at the corners here at site preparations LLC we use a woven stabilization fabric underneath every shed foundation that we install the fabric that we use is a class three fabric as rated by the American Association of State Highway and Transportation officials so the characteristics of a class three fabric are a tensile strength of 200 pounds and a puncture strength of 90 pounds so we put this in place underneath the foundation over the dirt before we put the gravel in place because it provides a lot more stability underneath the gravel and prevents it from sinking into the dirt and moving around over time this is the same type of fabric that's used in road construction so it's going underneath asphalt on highways so it's very highly rated in addition it helps keeps weeds down around your shed so there's multiple benefits and we highly recommend using some type of stabilization fabric in your shed foundation finally the main material gravel now it's important to keep in mind that when we refer to gravel we're not referring to actual gravel which is round River stone if you use River stone for your shed foundation it's not going to pack down tight the way that you needed to to support your shed it's gonna shift it's gonna move around so make sure that when you get stone you actually buy crushed stone when you're choosing crushed stone make sure that you choose the correct type so there's a variety of sizes and types of crushed stone the best type of crushed stone for gravel shed foundation is 3/4 inch clean stone it's also known as number 57 or 3/4 inch washed and it's called that because it's screened through a 3/4 inch screen and then it's watched in addition to get the dust and the small stone flakes off of it now some people recommend using crusher run or it's also referred to as number 411 or number 21 a but that's a crushed stone with the fines still included so it still has the stone dust in it the reason we don't recommend using that is it packs down too tight and it actually prevents water from draining through the foundation the way it should so you want to think of your foundation not only as supporting your shed but it's also providing a drainage bed so that's why it's important that you use 3/4 inch clean stone so that it can pack tight and the pieces can lock together and support your shed while still allowing water to drain through and keeping moisture away from your shed to calculate how much crush stone you're going to need for your foundation multiply the length width and depth of gravel in your foundation and you'll be able to calculate the total cubic feet divide the total number of cubic feet needed by 27 and that will give you the number of cubic yards and that's generally how crushed stone is sold we find that it takes usually three to four cubic yards of crushed stone for a gravel shed foundation but that varies depending on the slope of the foundation and also on how large it is in total the first step in actually installing your shed foundation is going to be the mark two corners off now if you're putting it next to a fence line or your driveway you can use that as a straight line and put the shed foundation and place parallel to that once you have two corners marked you can square off of them to mark the third and fourth quarters so you can either use Pythagoras theorem to do that or you can simply use diagonal lines and make sure that the diagonals are equal you can mark the corners either sticking small flags into the ground or you can tap in some of your rebar stakes and string a Mason's line between them for a little bit more permanent marking while you work now if you do go that route make sure you keep the stakes back far enough from the actual corners that they don't get loose and fall over while you dig you're going to want to measure out the dimensions of your foundation at least three feet longer and wider than the actual dimensions of your shed that will allow for 12 inches of gravel on each side of the shed for water drainage and then an additional six inches for the lumber perimeter once you have the cores marked and you're happy with it you can take your marking paint and draw straight lines down each edge of where the perimeter is going to go make sure you mark on the outside edge of the perimeter so that you can dig up inside of that once you have the corners marked for your shed foundation you're going to want to determine the exact level and slope of the location now to do that you can use a laser level if you have one and if you go that method you'll set the laser level up at the highest corner and then use a receiver on a transit rod to find the lower corners and exactly what the difference is in slow compared to the top corner another way to do that is to use a string and a string level tie one end at the highest corner and level the string to the next corner that you want to measure and once the string is level you can measure from the string down to the ground to find the difference in slope from the highest corner to the lowest corner another way to do it is to use a straightedge like a 2x4 and combine it with a carpenter's level to do essentially the same thing now that method works best on smaller shed foundations but if you do it that way you hold the straight edge you put it at the highest corner use the level to level it towards the lower corner and then again measure down to the ground to see what the difference in slope is [Music] once you have the corners marked in the slope measured you're ready to start excavating now it's going to depend a little whether you build up or dig down on your foundation that's exactly how you excavate if your door is gonna be on the uphill side of the location you're gonna want to build up to level if the door is on the downhill side you're gonna dig out the slope sometimes you use a combination of both where you build up a little on the downhill side and dig out a little on the uphill side and you can keep a level spot partway up the shed foundation for your door especially if the doors on the side once you have the corners marked and the slope determines you can start installing the perimeter for your shed foundation regardless of whether you do a build up or a dig out style of foundation you're gonna want to start digging at the lowest corner so move along the lowest corner and the lowest side of the foundation and dig away about two to four inches of topsoil about six inches wide this will allow you to lay down one piece of perimeter lumber and move around the the edge of the foundation as you work we recommend turning the four by six lumber on edge so four inch side down six inch side on the sides and building up that way so once you have the first piece down you just continue moving around the perimeter of the foundation and digging it out and keeping that wood level once you have the first perimeter down it's a good idea to measure the diagonals from corner to corner and make sure that it's still square before you continue building if your shed is going to be built up to level you're gonna start the second course at the lower end again you never lock the corners kind of like you would with a cabin or with Lincoln Logs and then you'll continue building that second course around the perimeter either until it goes completely around or until that course also moves below ground level at which point you'll start the third course and so on for however many you need that's gonna depend somewhat on how sloped your site is if you're digging out to level you're gonna start the second course also toward the lower end but you won't need to go the whole way to the bottom you just need to set the lumber in far enough that one end of it is above ground level and then continue digging out until that piece also either continues the full way around the perimeter or moves below ground level then you'll start your third course etc as you work you're gonna want to screw the pieces of your perimeter together so that's where you'll use the four exterior framing screws again make sure to use something that is hot-dip galvanized or has a better exterior coating so that it won't rust over time so you're gonna want to screw six to eight screws per corner as you fasten the four by sixes together it's also a good idea to run screws on the second course and above down into the course of lumber below so every two feet or so maybe put a four inch screw on each side and fasten it to the course below on shed foundations that are built on slopes more than 16 inches off level we recommend adding bracing to keep things from pushing out or moving around over time we use a style of bracing called a Deadman brace which is essentially a piece of lumber fastened perpendicular to the wall that's being braced on lower slopes you can simply screw the pieces of lumber perpendicular to the wall that's being braced and then attach another piece of lumber parallel to that wall from each side of the perimeter and use screws to tie everything together on higher braced walls we recommend actually building those perpendicular pieces of lumber into the wall to provide even greater stability on a build up foundation those pieces will point toward the inside of the foundation on a dig out they'll point outward into the bank that's dug out and so you'll essentially create somewhat of a retaining wall to keep your pad level and keep that perimeter in place [Music] once the perimeter is in place and screwed together you're gonna use your half inch drill bit and your drill to drill down through the perimeter every six to eight feet pounds two-foot rebar stakes through the perimeter and into the ground to fasten everything down now if the perimeter is more than three courses of lumber high at any point you're gonna start drilling again at every other course and use 16 inch rebar stakes to fasten those upper courses to the courses below now to provide extra side-to-side stability to keep it from pushing outward over time now once the perimeter is in place you can finish excavating any of the dirt that remains inside the perimeter you want to make sure that all the dirt is at least four inches below the top of your perimeter so that you can put four inches of gravel in place extra dirt can be spread around the outside of the perimeter to kind of slope the law and back up to the edge of the shed foundation in addition you can use it to create kind of a dirt ramp on the side towards your door if you wish make sure that all the dirt inside is very firmly packed if you're using a mini Skin sear you can drive back and forth on the dirt a couple times to make sure that everything is super firm before you add the gravel once the dirts excavated on the inside of the shed foundation rollout the stabilization fabric and pull it tight over the entire area you can run a few inches of it up the inside of the foundation perimeter and fasten it to the wood with a hammer tacker or with your staple gun [Music] with that stabilization fabric in place it's time to add the gravel use your wheelbarrow or whatever other method you use to haul it and spread the gravel around evenly on the inside now if your perimeter is leveled properly it should be pretty easy to spread it around using the edge of your perimeter as a leveling guide you don't want to make sure that again there's at least four inches of gravel on every part of the shed foundation so it can properly support a shed once the gravel is in place you're gonna tamp it to lock it in place and support your shed you can either use a hand tamper or if you have one a power plate compactor we usually start tamping from one or two feet inside the perimeter and work in a circular motion toward the center of the foundation once we get to the center we go back out and finish that one or two feet on the outside that helps keep the gravel from bunching up in the center if we started completely toward the perimeter it would start to push gravel inwards so because we leave that little space it helps keep everything level as we pack now if you're using 3/4 inch clean stone like we recommend even when the gravel is locked in place it'll still allow water to drain through and keep the moisture away from the bottom of your shed and that's it once that gravel is tamped in place you're ready for the shed whether you're building it on site or getting it delivered from a prefab manufacturer that foundation is going to support the shed as long as it's around if you need additional information on any of the points that we discussed here you'll find a link in the description that goes into more detail on each step of the process we put a lot of time into 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Channel: Site Prep

Views: 475,712

Keywords: gravel shed foundation, gravel shed pad, how to

Id: WpAc64Op7MA

Length: 23min 41sec (1421 seconds)

Published: Fri Jan 24 2020