Allotment Gardening Advice Help Chat

Chatting => Design and Construction => Topic started by: Francozeb on January 17, 2021, 14:28

Title: Shed base? (complete ameuteur)
Post by: Francozeb on January 17, 2021, 14:28
Looking for some advice on shed bases please...
Just taken on a half plot with no shed.
I really would like a shed, but honestly have no idea what I'm doing haha.
After a bit of research I moved away from the idea of laying slabs with pallets on top due the inevitable rotting.
My plot is on a floodplain so the base needs some careful consideration.
The next idea I thought of is to use the decking blocks and treated timber method. This is obviously not the cheapest method, which isn't ideal, but I would consider doing this.
Could I ask for thoughts and opinions on this please?
Or if anyone has other suggestions that would be muchly appreciated.
Thanks in advance  :)
Title: Re: Shed base? (complete ameuteur)
Post by: hasbeans on January 17, 2021, 15:35
You want a decent flow of air under the floor.  My shed is sat on breeze blocks and chunks of old brick wall that I found lying around the garden, with tanalised 3'x2' on top of that which the floor board sits on.  I used exterior osb for the floor and painted the underside and edges with bitumen paint but I'm sure pallet wood would probably do if you treated it, especially if you could get hold of hardwood pallets.  I also added some damp proof course, the type they put between bricks on a house, to the underside of the 3x2 to stop any moisture rising through the breeze.  May be overkill but so far so good.
It's also worth putting a strip of chicken wire around the perimeter of the base to discourage rats getting under the shed. 
Don't forget that if you cut exterior treated timber the ends need sealing or it will just rot from there.

Look at local timber and reclamation yards, often cheaper than the big retail diy stores.
Title: Re: Shed base? (complete ameuteur)
Post by: Francozeb on January 17, 2021, 15:48
That's great advice, thank you.  Ideally I want to  do it as cheap as possible.  I probably won't bother with any damp proof because it's going to get flooded at some point anyway. 
I think I'm going to have to secure the shed really well to whatever foundations I end up using too, to stop it floating away when it floods 🤦🏻‍♀️
Thanks for your response, muchly appreciated
Title: Re: Shed base? (complete ameuteur)
Post by: hasbeans on January 17, 2021, 16:26
If it's a few inches of standing water then just use bigger blocks (raised higher) to stand it on.  The weight of the shed should keep it in place. Of course if you get a few feet of standing water then sticking a shed on a boat hull might be the way forward!
Title: Re: Shed base? (complete ameuteur)
Post by: snowdrops on January 17, 2021, 19:03
From your introduction post it sounds like you might need to consider a shed on stilts! And Iím not joking. The last thing you need is a flooded shed. What do other plot holders do?
Title: Re: Shed base? (complete ameuteur)
Post by: Francozeb on January 18, 2021, 18:23
If it's a few inches of standing water then just use bigger blocks (raised higher) to stand it on.  The weight of the shed should keep it in place. Of course if you get a few feet of standing water then sticking a shed on a boat hull might be the way forward!

Haha, I did wonder if I could make a floating shed but it's beyond my skills  :D
Title: Re: Shed base? (complete ameuteur)
Post by: Francozeb on January 18, 2021, 18:27
From your introduction post it sounds like you might need to consider a shed on stilts! And Iím not joking. The last thing you need is a flooded shed. What do other plot holders do?

I have thought about this but have no idea how to do this  :wacko:
The other sheds on site are just raised slightly.  I've been advised to make sure there's areas for the water to flow through, and have shelves and hooks up high. 
Title: Re: Shed base? (complete ameuteur)
Post by: Dekzion on January 18, 2021, 21:37
Hammer in metal fencing post stakes? put a fence post in them and cut it off flush to the socket, then use them as posts to build your shed on. They'd be 4 inches off the ground, waterproof and secure. scrunched chicken mesh all around the gap to stop vermin?  That'd be my solution.
Title: Re: Shed base? (complete ameuteur)
Post by: hasbeans on January 19, 2021, 08:04
If you know a scaffolder I bet they could rig you up something or a french drain around it might help a bit.
Title: Re: Shed base? (complete ameuteur)
Post by: Welsh Merf on February 07, 2021, 21:17
On my last plot, I found three railway sleepers, levelled them out, and rested the 8' x 6' shed on top of them. It meant that air passed underneath to stop rot setting in. Never had trouble with vermin. I drove four wooden fence posts into the ground at each corner to stop it moving - we get a lot of wind on the Romney Marshes!
Title: Re: Shed base? (complete ameuteur)
Post by: grinling on February 09, 2021, 16:55
What size shed? simple small one can be moved by people and handles
My potting shed is on pallets due to the base getting damaged by water. Pallets are on paving cobbles.
Hubby shed is on concrete with hen house next door, allotments do not like concrete.
Sorting out drainage would help, I dug 2 downhill trenches to aid drainage on my site, luckily only a pond opposite.
Title: Re: Shed base? (complete ameuteur)
Post by: Subversive_plot on February 17, 2021, 09:08
Raising it up on stilts is the way to go if your allotment gets flooded.

1. Ask experienced allotment holders at your location, how deep is the worst flooding they have seen? If the worst version of the story is water 2 feet deep, plan for 4 feet deep.

2. How much shed do you need? If you are only planning on room for some hand tools, fertilizer and nursery pots, you need much less, there are sturdy lockable sheds made of plastic resin available for $150 and up (guessing that is roughly £100 and up). if you are keeping your own lawn mower and rotavator on site, you might need larger. There are metal sheds as well as resin sheds, buying one may cost less in the long run than building it yourself if you don't already have tools. Materials also cost a lot right now, under COVID. Estimate the size of shed needed, plan for a little bigger if possible.

3. CAVEAT: I don't know your local building codes, determine any local requirements before designing and building any structures, modify my instructions as needed to meet code. To create a platform on "stilts", determine the height from step 1 (above), horizontal "footprint" dimensions from step 2. All wood materials used for your platform should be exterior grade, pressure treated. Carefully measure where the corner posts need to be, dig narrow holes roughly 0.5 meter deep for each post, construct your platform with the posts in those holes. Dry fill concrete mix in the hole after the platform is built and is level. Pour water into the concrete, use a wood pole to push up and down through the concrete to mix in the water. Depending on height, you may also need to build steps or a ramp into your shed. The concrete provides a firm footing, also anchors what you have built during a flood.

4. If all this sounds like too much trouble and cost, consider just bringing tools from home in the boot of your car.