Help with shed base dilemma

[nomy]

Right, time for another shed base question! I have searched a lot and gained a lot of helpful answers. But I am still stuck. And a bit of a construction noob

I intend to buy a standard 8 x 10 shed to house a few tools etc and my motorbike, so I need a fairly strong base. The problem I have is that I live in a rented house, so no concrete base for me. The only stable enough area has a smaller area of concrete than the shed base ( about 6 x 6), and it is slightly unlevel. My intention is to sink into the soil some reinforced concrete gravel boards along the full length of two sides ( one length, one width), and use the existing concrete along the other two edges. I would then sit some some 3 x 2 bearers, but this would mean that two of them (along one end and one side) would have to be raised by about 1" as they sit on the gravel boards.

My questions are: is there anything I could use as packing to support the bearers? How many bearers would you suggest I run along the length of a 10 x 8 base? And should I have a few cross beams?

I know this is not ideal, but it really is the only site I have.

Many thanks.

 

[Burnerman]

Is it possible to extend your base by laying some paving flags down?
They can come up again when you move on.
John

 

[nomy]

Thanks for the reply burnerman.

Yes, I could extend, but this wouldn't cure the main issue of unlevel existing concrete. I probably didn't explain very well, so I will add a pic:

Untitled

• nomy
• 11 Oct 2012
• 1

As you look at the image, the far left corner of concrete is slightly lower than everywhere else. Along the front where the metal bar is, I will sink in the concrete gravel board. But as I level it up to match the far left corner, there will be an increasing gap from 0" to 1.5" when I place the length of 2x3 along the side and onto the gravel board. The same is true for the width. Along the width from far left to right as the level rises, I will have to go onto the grass and sink in another gravel board along the length. This will also have top be raised about 1" on the far right hand side. Again, this will mean having to pack again along the width of the frame to support it. And the same goes for all other cross beams.

The long and short is that the right hand length of 2x3 will sit flush onto the gravle board, and so will the width at the bottom of the picture. The left hand beam will need to be packed as it runs from top left to bottom left, as will the top wicth beam as it runs left to right.

So really, my question is: Is it feasible for me to use some packing to support where necessary? And what material would be best..I was thinking just pieces of ply. Or maybe slate?

I know this is not ideal at all. But short of fresh concrete which is a no go, I just can't think of any alternative.

I hope that makes better sense of my problem

 

[Burnerman]

I'd still be wanting to attack that old concrete really (you seem to have permission to sink gravel boards in?)
No matter - if you want to pack your boards up to get them level, only stone or slate aggregate will do - even WBP ply will rot away in a short time.
John

 

[nomy]

I've had a rethink, and a chat with the landlord. As the concrete is a mess anyway, I've convinced him that having paving down will give him a patio when we leave, and anything is better than the mess already there! So my intention now is to pave over the concrete and onto the grass. Since I will be paving over a hard base AND soil, should I put down some hardcore and sand over the grass, or will a dry mix of sand be enough do you think?

Thanks.

 

[Burnerman]

Dig the grass out, compound the earth beneath, add some hardcore and then bed the flags down on sand, or better still a concrete dry mix.
John

 

[nomy]

Hardcore, and dry mix it is then. Thanks a lot for your advice John.