How to Build a Great Shed, Base Upwards




Introduction: How to Build a Great Shed, Base Upwards

About: Very simply we are a young couple who are trying to make a mark on the world.

This is going to be a nice easy guide on how to build a shed/workshop, including how to lay a solid base for it. Any calculations that I do, simply substitute in your own numbers.

I am not going to beat around the bush with this, many people have done in-depth guides on every part that I will mention, but I assure you if all you want is to build a great shed then follow this guide and with a bit of common sense, it will be yours.

When I was doing this project myself, I did not plan on making an instruction guide, so I did not take anywhere near enough photos of my project so I will include what I have, in the hope that they give you some idea of what I am talking about. But please excuse me if some of the photos do not make chronological sense.

Without any further ado, lets get to it.

Step 1: Planning

Planning is something that I wish I had done more of before beginning the project. I had however created CAD designs of my shed which came in extremely handy when measuring out materials. Obviously, not everyone will be able to do that so I would suggest that you should at the least draw out rough sketches of a design for your shed. Modify your sketches or my CAD design to suit your needs, including the measurements. Go to the Frames step to see the detailed drawing of each frame to get the measurements.

Be aware that no matter how hard you try, the plans you originally make will somewhat change. This is not a bad thing, just be prepared to modify your designs as you go or if you see a better style that you want to go for, do not be afraid to completely change it.

Primarily, if you are laying a base as I will show you in Step 2, you need to take into account the height you want the shed to be. This is the second decision to make after choosing your location for the shed. The height is crucial to the overall look, too big and it overshadows your garden and sticks out like a sore thumb, too small and you are going to be constantly banging your head and have no room for storage. I opted for the shed at its highest point to be 7ft tall and at the low points 6ft 6. This way I did not have a risk of banging my head and also had the option of more storage.

Make sure that you do lots of research into the materials that you need. Depending on your location, the sizing of wood may vary so be careful to take this into account. At each stage I will list the materials needed, instead of presenting you with a long list of all the things you have to buy and it becoming a daunting task. This will also help break up the project into different sections so if like me your work load is heavy, it is at least manageable.

Step 2: Digging and Boxing

Materials Needed:

30cm Stakes x 20 ( 5 per side plank)

Four lengths of shutter board (length dependent on calculated size below)

Assortment of screws

This step is not too material heavy. The aim is to create a box that is supported on every side, in order to contain the concrete that we will pour in during the next step.

Once you have made your mind up on the height of the shed, you need to take into account the base height which could alter the overall height of the shed. Many people have different ideas on how a shed base should be made. I believe a concrete base is the best way, others choose to do slabs, compacted gravel or even wooden beams. All of these options have merit depending on your needs but I prefer the strength and look of a concrete base and this is what the next step will be about, so if you have found or know of another way of doing the base then skip this step and the next.

To make the shutter box its very simple, first mark out the base area of the shed. This can be calculated depending on your style. My area was very easy as I already had three of the sides done by the gravel boards of the garden; as can be seen in my photos, my shed was positioned at the bottom of my garden making this possible.

If you have all four sides exposed, this is when the shutter boards come in. What you need to do after marking out the area is to make sure it is first square by measuring diagonally from corner to corner and ensuring they equal the same amount; alter the corner positions as needed to make them equal.

(I would advise adding about 5cm of extra base on every side to account for mistakes and tolerances).

Once they are accurate and you are happy with the positioning add the planks along the edges, supported on the outside by the stakes.

When adding the planks, I would advise driving five stakes to support each plank. You DO NOT want them to slip or move under the weight of the concrete. The total height of the planks and the stakes should come to the height of the base that you decided earlier. Make sure the stakes are either lower or the same level as the planks as this may cause an issue when levelling the concrete. It is very important to have it all level or at least slightly slopped in one direction.

You should aim on the depth of the base being around 5cm or greater.

Once you have this securely in place and you are happy with it, you are ready for the next step. If there is a slight problem with this box, do not settle for "it will be alright" as this will lead to many problems later.

Step 3: Concrete Base Making!

Materials Needed:

Cement x Calculated amount below

Ballast x Calculated amount below


Cement x Calculated amount below

Sand x Calculated amount below

Gravel x Calculated amount below

as well as Water and a Cement Mixer!

So now for the messiest part of the project, well it was for me.

Again many people have different ideas on the ratio for concrete, I have made a nice little info-graphic that is available on our website, instagram or pinterest accounts, that show three different ratios that are used for different types of cement mixing.

In all honesty the ratio used to make cement is very dependent on your opinion and the environments its exposed to, if you're interested many people have done more detailed explanations on it.

The first step is to calculate the amount of materials you need, this is not too complicated if you substitute your numbers in for mine.

Step 1:

First calculate the volume of the box you have made:

Volume = Length x Width x Depth (meters)

Volume = 5 x 4 x 0.2

Volume = 4 m^3

If you do not understand those numbers they are the measured amount from the box but converted into meters.

The ( m^3 ) is the unit for it and says meters cubed.

I got 0.2m for my depth from my measurement of 20cm.

Step 2:

Now we have the volume of our box we need to bring in the ratio we will use for the cement mixing and use this to calculate the amount of each material needed.

For this, the mix ratio is 5:1, ballast to cement, respectively. Or if you have sand and gravel instead of ballast (the same thing really), the ratio of 3:2:1, sand, gravel and cement, can be used.

We will solve the ballast and cement ratio as this my recommended method to use and from it you can calculate the sand and gravel quantities.


Volume of box = 4m^3

Add ratio amount together = 5 +1

Ratio = 6 total parts


4m^3 / 6 = volume per 1 part

Volume per 1 part = 0.67m^3

This means the volume of each material can be found:

Ballast = 0.67m^3 x 5 (parts in ballast)

So the total volume of ballast needed is: 3.33m^3

Cement = 0.67m^3 x 1 (parts in cement)

So the total volume of cement needed is: 0.67m^3

These are the volumes of each material you will need, once you sub in your values. When buying the materials each one will tell you the volume it has, use this to calculate the amount needed for your base.

Now the horrible maths is out of the way, lets get to the actual mixing and pouring. To do this, put in the materials in the correct ratio as above into the mixer. Add water to the mixture whilst it is spinning in the cement mixture until it reaches the consistency that is capable of holding its own shape in the form of a flat topped cone.

Once this is achieved, pour it into the box and repeat until you reach the top of the box in this case you need a length of wood. Whilst making a sawing motion over the box, resting the ends of the wood on the shutter boards, pull the wood towards one side from the opposite side, leaving a nice smooth cement level behind it. If you do not understand what I mean by that, do a quick Youtube or Google search and this will explain it better.

Now that you have a nice levelled base you can move onto the fun shed part. Which is a lot less messy!!

Step 4: The Frames!

So this becomes the part where I cannot give you exact maths and wood length calculations. That my friends, if you have got this far, you can do by yourself. Hint: Use your designs or mine.

With that in mind:

Materials Needed:

Wood for frame (typically 2" x 2")

Assortment of Screws

Damp Proof Coursing

So after that in depth guide on materials that you should buy for this step, I am now going to attempt to guide you through building the shed. Now each of you will be doing something different so this will not perfectly apply to everyone, but because my easiest frame to build was the back we will start with that and you can pick and choose parts from each section to help you make the rest.

Back Frame

So for the back frame use my drawings for the layout of the planks of wood and where to join them together and use your own drawings and measurements to cut the wood to the correct lengths. Make the down beams the same distance apart to enable the strength to remain in the frame whatever the overall distance of the back is. I would advise on the top and bottom of each length of wood for two screws to be added to secure the wood in place without allowing them to move.

Side Frames

The side frames are exactly the same as the back frame, just smaller.(Depending on your design) For me, building these frames was the easiest part of the whole build.

Front Frames

These are the hardest frames to build as they contain the two windows for my shed, meaning I had to alter the frame design to be able to hold the window and the weight of the roof. To do this, follow my plans and again alter the dimensions to suit your desired window frame. This method of adding a window can be used on any side of the frame. The way to calculate the space needed for the window frame is to work it backwards from the glass/perspex size that is desired.

It is at this point I would advise adding the damp proof coursing, something which I did not do until much later on in the build, which wasted so much time and energy. Just hold it in place with small tacks and overlap the edges around the base of the wood to help protect it.

Step 5: Cladding

This next step can be done now or after the frame is attached depending on your preference, but I chose to clad the frames bottom up as high as I could whilst they were laying flat to reduce the difficulty of cladding with it standing up. As long as you get your measurements right and the cladding level, there is no problem with this method.

Materials Needed


Nails ( 40mm or greater)

The choice of cladding that you use is up to you, I went with ship-lap as I prefer this style.

Before cladding begins, you must first look ahead at how you plan on joining the walls together. I used nuts and bolts. For this I drilled the holes in the frame and put the bolt in position before cladding over them to hide and protect them. If however you simply want to screw it together this will also work fine.

Side Walls

Start from the bottom of the frame and cut the cladding to the length of the frame for both of the side walls, simply place the first length down against the frame, I would advise leaving a 1cm gap up from the bottom to stop the cladding absorbing water that may pool near it. It is of great importance to make sure the level of the first plank is correct as this will guide the rest into the correct position. If it is off, there is a big chance that you will end up with a slanted cladded wall, which does not look great.

With the side walls you can clad them almost all the way up leaving just one plank down from the top to help with joining the roof and the other walls.

Back Wall

The cladding for the back wall is made in exactly the same way as the side walls, with the exception of the cladding overlapping the end of the frame by 50mm on either side to account for the frame timber. Forming a nice corner with no frame being shown.

Front Walls

As you can see in the above photo, I made the front wall in two sections. This made it easier to build the overall structure and connect them together later. To clad these frames, use the same method as the other walls with a 50mm overlap where the side walls will be attached to the front frame, again to hide the frame. It gets a bit tricky when it comes to cladding around the windows, as one side of the window frame the door side needs to match the frame exactly; to allow the door to fit. On the other side of the window frame, for the window to fit, the cladding needs to match the frame exactly on the window side and overlap on the side where the other wall joins. (Get your head around that, or simply just look at the photo its easier.)

Step 6: Join the Walls!

This is the part where you really start to see all your hard work coming together.

Materials Needed

Nuts and bolts


Length of timber

Also if you have enough "man-power" this can be the easiest part, although being typical me I did it by myself. Which I strongly advise against, you do not know being stuck till you are holding two walls up at the same time that are bigger and heavier than you are, all whilst trying to align the bolts you previously put in. My back was not happy.

So with a friend, I suggest starting with the back wall and connecting one side wall to it, this is the difficult part as you have to support both frames equally and make small changes to them, for alignment. Once you align the bolts, you're golden. From this point, the shed walls should support each other and this makes it easier to attach the rest in whatever order you want. The same practice is done with the screwing but you will definitely need more than one person to do it and you can find out why for yourself.

Try to make the walls as square and level as possible, I did this by attaching a length of wood across the top with screws to hold it in place whilst I worked on the other walls. I ensured that this did not move, otherwise throwing the whole shed out of alignment.

Use the same method for the rest of the walls. When you're happy with the frames, shape cut and screw in the length of wood, that should be cut to the interior dimension between the two side walls and attach it across the two front panels to make it one front frame. At this point you should have all of the walls up like in the photos, if so well done!

Step 7: The Roof!

Well if you have made it this far well done for, first reading my long post and two for getting your shed to this point, trust me I know how much work you put in.

Materials Needed

More Timber 2"x4"

and of course more screws

Sheets of 10 - 20mm marine plywood

So using my designs, it's very easy to see how I made the roof triangle frames. Unfortunately, the measurements on it for you will be all but useless, depending on the sizing and shape of your shed. But it gives you an idea about how to make your own. I went for a shallow slanted roof similar to a summer house.

For this I created four identical triangles, two for the front of the shed and two for the back to form one big triangle. Before joining these to the frame I added two straight lengths of wood similar sizing to what is used on scaffolding. I turned it vertically as this adds a lot of strength to the centre of the shed and allows you to walk safely in the middle of the shed ( at your own risk).

This gave me a good place to attach the triangle to, on two sides. The bottom and vertical length of the triangle. With all four triangles securely in place as can be seen in my photos, you should add lengths going straight across between the front and back, as well as lengths of wood between the centre and the side walls, as shown in the photos. This adds strength to the roof and mounting points for the planks of wood being used for the roof. The photos show the best description of this, much better than I can write.

Once those cross-beams are attached, the roof panels can go on! My roof was made up of a mixture of recycled planks and plywood, as can be seen in the images. Make sure the plywood you use is treated, otherwise the weather can cause it to expand and warp, some people call this "blowing out".

Recycle where you can to save wood and money!

With the planks of wood down you can finish off cladding up to the roof and have fun cutting the cladding at the awkward angles at the top (Good Luck). Then with the felt added, which is covered by many people so I wont go into it, YOUR DONE!! Well at least with the worst of it.

Step 8: Door and Windows

Materials Needed

Wood (cladding or your choice for the door)

Timber 2 x 2


A door


Perspex or Glass

Well guys, if you are here you've made it to the last bit of instructions, that I am sure at times made no sense to you and felt vague but that's the beauty of making something yourself, it's not meant to be perfect and you're supposed to learn from it. So if you have made it this far, then be proud of yourself!

Last job, the doors and windows. For the windows, you have another choice, opening windows or permanently shut windows. I went with opening. But to explain that, I would need another tutorial. If you are going for permanently shut then its simple, just attach a small square beading of wood to the inside of the window frame. Apply a small amount of silicon to the side where you plan to put the perspex or glass, position the glass in place quickly and attach another frame of beading the opposite side of the glass to the first in order to hold it in place. If you are feeling adventurous try and come up with a way to do a opening window yourself.

So last but not least, the door. I made mine very simply as a rectangle with one length of wood across the middle and two lengths of wood going diagonally from corner to corner, one for each half of the rectangle. This helps stop the door from slanting. I then attached the hinges, as shown in the images with two hinges, one at the top and one at the bottom. A general rule of thumb is a hinge should be a third of the width of the door, when it comes to heavy unsupported doors. After that it was a simple bolt and padlock latch that I attached to secure it and


Congratulations!! Now do whatever you want with it!!

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    12 Discussions


    2 years ago

    Hi, this is a nice shed. Do you roughly know how much you spent in raw materials (base excl.)? I'm thinking of building one of my own but I'm unsure wether i'd be saving much by building a custom shed.


    Reply 2 years ago

    In my experience, the cost of materials per sq ft of a custom shed will exceed that of the materials used in a 'ready made' shed because they typically use less material - in the US you find the ready made stuff is built on 24" centers and most folks who build their own build on 16" centers for (wooden Base), wall and roofing sections.

    Similarly, ready made sheds include a minimalist roof structure where you and I would build for a Snow Load or Hurricane.

    Door and window openings 'from the factory' are typically lite weight and (relative to those in our homes) rather flimsy. When individuals build, they trend to employ a higher grade window and door - in part to justify the labor involved.

    If you are simply attempting to protect a motorcycle or lawn mower from normal weather exposure, a cheap metal pre-fab shed on a foundation of large patio blocks over plastic should do the job as cheaply as it can be done and in the least amount of time with the least amount of effort.

    The result will not be as pleasing - esp as time goes on and the thing begins to rust and such. But your cycle will be protected.

    While building it yourself may cost as much as a ready made shed, yours will likely be larger, stronger, more appealing to the eye and even insulated and electrified with ventilation and such on a permanent slab - a valuable addition to your property in lieu of a tin eyesore in need of repairs!

    It is not always simply a matter of the money.


    Reply 2 years ago

    Hi, my rough costings came to about £800 - £900 excluding the base cost. Hope that helps!


    2 years ago

    That's exactly what I need and what I have in mind. I'll use this 'ible as a reference. You keep saying you used 2x2s but your pics show 2x4s, though. Anyway, awesome job!


    2 years ago

    Looks great. The roof pitch would need to be sharper for my region. I debated upon the flexibility I needed and time to build before winter arrives, and decided on a 8' x 8' x 8' Home Depot vinyl shed. My two motorcycles are now out of my garage which I am converting to a woodworking shop so that I can make wooden sheds like this one.


    2 years ago

    Trim around the door would finish it off nicely. Make the pitch on your roof the same as your house. The flat roof shown would be subject to collapse in our snowy country. You saved money using the cedar siding rather than using plywood with siding on the exterior. The cedar looks far better than vinyl siding. Thanks for sharing your information.


    2 years ago

    Good work! I debated in my mind for many months what I wanted, how much I wanted to pay, how much ongoing maintenance I wanted to contend with and how difficult a project I wanted. I ended up going with a packaged 8'x10' UV-resistant plastic kit (that had a full floor, 6 skylights and 4 windows for interior illumination, 2 full-depth shelves and a double door for over 3' opening and about 6' 3" minimum headroom with more in the center) from our local "big box" store, a used/never installed steel shed floor brace, 4 solid concrete blocks and a little over 2 sheets of pressure-treated 3/4" plywood. I set up the concrete blocks as a floating level foundation, assembled the steel bracing and sat that on the concrete blocks, fastened the plywood to the steel bracing with exterior wood screws and assembled the plastic kit on top of that. Worked out extremely well, looks much better than anything I could have come up with, absolutely NO periodic maintenance, and it could also be used as a playhouse for my grandchildren if I decide to clear out the 2 lawn mowers, fertilizer spreader, 2 bicycles, 1 motorcycle and a lot of sundry hand tools/pump sprayers. I think I spent less than $1100 total and it took me maybe a week total.


    2 years ago

    Nice shed! Looks about the size I want.


    2 years ago

    I like this instructable, I also have plans for a only suggestion would be incorporate different units of measurements for ease of understanding.I myself am a little intimidated by the metric system so I tend to stay away from these types of plans, although ,yours looks great. If you could have included inches and feet to meters it would have been easier to understand.Thanks, great project,look forward to trying this once I convert it over.


    2 years ago

    That came out really nice! Great work guys :)