Weight on new slab - how long?

[James Davis]

How long after pouring are you supposed to wait before putting weight on it.

My builder has put fibolites on there in seven stacks of ten blocks in a line across the slab on boards. Pour was five days ago.

 

[Notch7]

24 hours would be my guess

the important bit is that the type 1 is properly compacted

 

[Dereekoo]

well 10 blocks laid flat on each other is 1m high which is equivalent to a load of 1000kg/m2 which equates to 0.1N/mm2
Assuming 20N/mm2 concrete (1-2-4 mix) crushing strength at 5 days will be about 50% i.e. 10N/mm2. As Notch says if sub base is OK no issue

 

[^woody^]

Perhaps that's why the [unnecessary] reinforcement went in after all?

 

[James Davis]

Perhaps that's why the [unnecessary] reinforcement went in after all?

I blame the building inspector for recommending it. Not that they actually examined the ground in their 25 second visit, which I'm paying hundreds of pounds for. Oh well.

Based on what you've seen, would that reinforcement do any harm based on how it ended up being a tad uneven with some crushed plastic feet? 150mm slab altogether.

 

[Deluks]

I blame the building inspector for recommending it. Not that they actually examined the ground in their 25 second visit, which I'm paying hundreds of pounds for. Oh well.

Based on what you've seen, would that reinforcement do any harm based on how it ended up being a tad uneven with some crushed plastic feet? 150mm slab altogether.

Whilst the feet are crushed, the steel is not touching the membrane. You can stop worrying about that bit now.

 

[James Davis]

Whilst the feet are crushed, the steel is not touching the membrane. You can stop worrying about that bit now.

Yes, but don't the crushed feet basically mean holes in the slab which will be points of weakness? Or are the bars amd slab as a whole going to work together to outweigh that?

 

[Deluks]

The 'holes' are too small and too far apart to cause any weakness.
It's got membrane beneath so it's all protected from moisture. It will more than likely outlast you.

 

[noseall]

Pour was five days ago.

No problem.