Concrete fence posts for shed base?

[JP_]

Got a 7x9 foot shed. Just removed a 4x6 ft shed that was on this old base. Base is about 7 ft square. The shed was testing on 3 9ft 5x2s, which rotted a bit.

So, thinking of putting 3 9ft concrete fence posts down to support the base. Will over hang old concrete base, but i can support end a bit, although doubt they'd need it?
Obviously will clean base up more.

 

[foxhole]

Fine as long as the new shed base is substantial .

 

[JP_]

maybe overkill? Just use normal wood?

 

[JohnD]

You say your old shed was smaller than the base. So rainwater will have fallen on it, and possibly pooled, accelerating rot in damp timbers. Especially if you did not have gutters to remove water falling on the roof.

If the new shed is big enough to overhang the base, and you scrape away surrounding soil so it is lower, water will not run onto the base and you will only have dampness rising from the ground, which DPC under the bearers will block.

 

[JP_]

Good point. Have cleared more of the base - I guess there was once a larger building on it. There are lots of grooves which were full of soil, leaves, woodlice, ants, worms etc. Think it might make sense to have a new layer of concrete over the whole lot.

The previous shed had no bearers, just a chipboard base on the ground. With a carpet in it to help reduce air flow!

The base is just over 7 foot wide, and the strip of concrete by the fence is a bit higher too.

Some of the shed and base:

 

[JP_]

Posted the job trade site, see if I get a sensible quote.
How much would this sort of job be, £200?
Could do myself, but would have the hassle of getting materials, finding a mixer, etc.

 

[JP_]

First quote back ... £380.
£65 per square metre to lay an inch of concrete? Might as well get it tarmaced!

 

[Deleted member 174758]

First quote back ... £380.
£65 per square metre to lay an inch of concrete? Might as well get it tarmaced!

Yes, but plus shuttering and maybe two guys for half a day and £65 to £85 for a cubic metre of concrete (the minimum you seem to be able to get delivered), so maybe not too far wide of the mark?

 

[JohnD]

First quote back ... £380.
£65 per square metre to lay an inch of concrete? Might as well get it tarmaced!

if it's so easy, hire a mixer, buy a barrow and a shovel.

It gets heavy, mind.

 

[JP_]

yeah, might have to DIY it.

 

[JP_]

For the amount of concrete I need, I should be able to hand mix it....

 

[JP_]

OK, if I decide to mix.... can I just work out about how much I'll need, and mix it on the existing slab and spread it out, then smooth it off with a bit of wood?
Or is it best to mix in a wheelbarrow and pour on, then spread?

 

[cwhaley]

Concrete fence posts are a totally feasible idea. I helped my dad put together a 10 x 12 workshop and the floor for that sits on lengths of fence posts which are on top of a concrete base we poured.

As long as the concrete slab they sit on is sound, they will last a long time. Might just need some packing to stop the base from wobbling.

 

[JP_]

After struggling to find somebody interested in doing a base, maybe a few posts is the best option now.

 

[cwhaley]

Sorry the pictures didn't load for me originally, just seen them now -- leveling and extending that base is the best method. You can hire a mixer by the day relatively cheaply (£12 a day here) and get a half-tonne bag of ballast and a few bags of cement. It is a small job for a tradesman so that's probably why you're struggling.

It's hard work shifting it all but worth it.

If you were to just use posts, you'd have to do put a lot of packing underneath the posts to secure them with weight on the top.