4 inch concrete slab for garage

[Mikeyken]

Hi
Im building a steel rsj garage, and I'm planning on putting in a 4 inch concrete slab with compacted stone base and reinforcement mesh. I will need to drive a 5 ton teleporter on the slab to lift the steel into place. Will the 4 inch slab hold up without cracking? Or should I go for a thicker slab?? Any help would be great.

 

[ree]

OP,
Six inches is the typical slab thickness - blind the stone with sand - and then lay a DPM membrane - then sit the mesh on some kind of chairs/spacers.

 

[Notch7]

4” is a bit thin for a telehandler

 

[robinbanks]

Those must be some steels if you "need" to use a 5 ton TH to lift them in..

 

[Mikeyken]

Those must be some steels if you "need" to use a 5 ton TH to lift them in..

They are 16ft lengths of 180mm H iron and need to be lifted 18ft high.

 

[Ivor Windybottom]

You might as well put some rebar mesh in while you're at it, give some safety margin for your telehandler and good insurance for the future too.

I put some in a 6" floor slab, I just put one layer resting it on concrete common half-bricks to put it mid-way in depth. Vastly better than nothing, I really didn't need it so it was just a bonus feature really. But the proper way is two layers, one near the bottom and another near the top. The theory is that if a slab bends then it puts tension across the top or bottom depending whether the load is in the centre or edges, so the rebar takes it instead of the concrete cracking. I guess with it in the centre it will allow some stretching but will stop it snapping, definitely much better than just concrete which has almost no strength in tension.

 

[Ivor Windybottom]

You should leave it a number of weeks before driving on it. Possibly a month or two for your telehandler. There will be concrete strength percentages somewhere online, it takes a long time to react and develop its strength.

I'd put some OSB or similar board down too, spread the load by stopping those hefty ridges in the tyres digging in and creating point loads.

I had one on our (very old) concrete driveway from a farm contractor to move some soil and deliver bricks. Smashed it to bits all over the place.

 

[Mikeyken]

You should leave it a number of weeks before driving on it. Possibly a month or two for your telehandler. There will be concrete strength percentages somewhere online, it takes a long time to react and develop its strength.

I'd put some OSB or similar board down too, spread the load by stopping those hefty ridges in the tyres digging in and creating point loads.

I had one on our (very old) concrete driveway from a farm contractor to move some soil and deliver bricks. Smashed it to bits all over the place.

Thanks I would not of thought of that. I'll give it at least a month anyway, last thing I want to do is destroy it.

 

[scbk]

Out of interest, how big is the garage, are you building it yourself, is it going to be like a mini portal frame building?

 

[Mikeyken]

Out of interest, how big is the garage, are you building it yourself, is it going to be like a mini portal frame building?

It's 47ft x 30ft x 16ft high steel frame with blocks 8ft high and box profile sheeting on roof and down the sides to meet blockwork. I got the frame made up and will put it up myself.

 

[carmanmemoranda]

Thanks I would not of thought of that. I'll give it at least a month anyway, last thing I want to do is destroy it.

New garage floors for putting ramps onto, always get told allow at least a week per inch of depth plus a week extra before even attaempting to drive on it.

6 inches is the minimum for 2 poster and 4 poster standard ramps, and installers always say at least 8 weeks before they will even come and look

 

[scbk]

It's 47ft x 30ft x 16ft high steel frame with blocks 8ft high and box profile sheeting on roof and down the sides to meet blockwork. I got the frame made up and will put it up myself.

Sounds a good shed, I'm nosey, put up some pics when you do it!

There was a guy I met through in Aberdeenshire, he put a slightly bigger shed up himself, he had the frame made in Northern Ireland, said it was cheaper than any supplier in Scotland.
The shed was 19m x 13m (62ft x 42ft)
He built the shed first then once it was clad did the concrete floor in sections. Gave him a roof over his head, and no worries about machines on the new concrete.

 

[Mikeyken]

Sounds a good shed, I'm nosey, put up some pics when you do it!

There was a guy I met through in Aberdeenshire, he put a slightly bigger shed up himself, he had the frame made in Northern Ireland, said it was cheaper than any supplier in Scotland.
The shed was 19m x 13m (62ft x 42ft)
He built the shed first then once it was clad did the concrete floor in sections. Gave him a roof over his head, and no worries about machines on the new concrete.

Will do.

 

[ree]

OP,
I dont know your design or the weight involved - but the thing is you could have perimeter footings deeper than the slab. You might also have point loads where the post are, and they will transfer the load deeper than the slab down to the footings.
Your perimeter footings, & the slab should all be poured in one go - dont attempt to do it in sections.

How long you wait is your call but I've worked on factory and gym floor pours that had machines on them in no time at all so to speak - thats commercial urgency which you presumably dont have? So your month looks good.

FWIW: I'm sure your a very competent person & everything will go fine but any doubts about what you intend then maybe get a concrete guy in for a day?