Shed sinking, help to prop it up!

[Maxw42]

Hello forum! First time post here.

I am a fairly handy amateur carpenter and had a builder come around to replace the floor in my shed, which was very rotted with wood worm (it was the removal that I couldn't do, as the rot creaped me out).

While his construction method was good, he made a very very bad mistake. The previous beams under the floor extended under the walls. He removed these, but the new beams ended about half a cm before the walls, creating a floating floor, so that he could wrap waterproof lining all the way around the edges.

So, obviously, the shed is now slowly sinking, as there's nothing holding up the walls except the facia. There's about a 5cm drop so far.

Underneath the new floor he installed is a basic concrete slab under the whole shed, which appears very level.

I intend to take the new floor out, fix the walls, and put the floor back in, and here's where I need the advice:

I need some hind of technique or tool to prop the walls up a bit at a time and then something to rest the walls back down. Presumably I can just stack bricks?

Anyone have any advise as to:
A. If bricks are the best thing to use or
B. How on earth I can prop the shed up to begin with, to fit something underneath it?

Thanks so much in advance for your help!

Kindest,
Max

 

[JohnD]

you can probably attach temporary posts or legs to the shed, probably in the corners or wherever the shed has its frame supports. You can then jack them up, which will raise the shed. Then fix some kind of new support or internal post or brick plinth, the lower it and remove the temporary ones.

you might not have to remove the floor.

I find 70mm fenceposts quite useful for this.

some photos would help.

 

[Maxw42]

Hi John,
That makes sense; will definitely try the posts

What I can't figure out is what to use to prop it up to get the post attached at the right height. Just a car jack? Is there a better way?

Kindest,
Max

 

[JohnD]

fix the post to the shed, then jack up the post and it will lift (that corner of) the shed.

then you can wedge something under the bottom of the first post, and jack up one of the others

unless, say, you can buy a few jacks cheap at a car scrapyard or something

I used a Peugeot scissor jack recently on a comparable job when repairing a fence

you need a baulk of timber under it to prevent it sinking into the ground.

sections cut off another fence post are sturdy for propping.

you can buy bzp steel studding (M8 is suitable) very cheaply, to bolt the post to the shed. Large bolts are much more expensive.

 

[Maxw42]

Wonderful; thank you. No place to put the jack until I take the floor out. Will get the jack ready and then do it all in one.

 

[^woody^]

Winbag and some timber or suchlike packers.