Advice required on slab

[joe90]

I am going to build a timber (log type) garage 5m x 6m at my new house under permitted development and I need a slab for it, I propose 100mm hardcore or MOT whacked down, sand blinding, dpm membrane then 100mm of concrete with steel mesh embedded. Is this reasonable?, only a kit car and motorbike using it so no real heavy loads. 

[TonyT]

 

what kind of logs? sufficient weight  in these to have a deeper perimeter foundation?

 

I’ve been using c35 a lot for work foundations for special columns with fibre additives to save climbing down a 1 m hole and placing mesh on chairs

[joe90]

 

It’s only 44mm log “effect” construction so minimal weight in the garage itself .

Edited May 25, 2023 by joe90

[TonyT]

https://nhbc-standards.co.uk/10-external-works/10-1-garages/10-1-4-garage-floors/

[TonyT]

Make sure the concrete is pokered. 
I can’t find the info, but sure it increases concrete strength significantly.

 

concrete like smooth chocolate or 

aero bar chocolate I know which I would prefer for strength 

[Chanmenie]

33 minutes ago, joe90 said:

I am going to build a timber (log type) garage 5m x 6m at my new house under permitted development and I need a slab for it, I propose 100mm hardcore or MOT whacked down, sand blinding, dpm membrane then 100mm of concrete with steel mesh embedded. Is this reasonable?, only a kit car and motorbike using it so no real heavy loads. 

Have you looked at fibre reinforced concrete, it’s cheaper and easier than rebar mesh and very strong.

The company that did my slab used the same stuff in their yard at 150mm and they park artics on it, 100mm is ok for fork lifts so should be plenty for your car

[JohnMo]

11 hours ago, Chanmenie said:

Have you looked at fibre reinforced concrete, it’s cheaper and easier than rebar mesh and very strong.

The company that did my slab used the same stuff in their yard at 150mm and they park artics on it, 100mm is ok for fork lifts so should be plenty for your car

I've done a couple of garages over the years, each time with fibre reinforced instead of steel.  First was about 8 (6x4) years ago, no cracks or issues. Both of ours were 100mm, the current is bigger 6 x 10m. That was pour a year ago, no issues.

[SteamyTea]

Why not put a bit of insulation in as well, you know it makes sense.

[PeterW]

Dig down 250mm and shutter the edges to the correct size with OSB then put 150mm of EPS in the middle of it up to 250mm from the edges, DPM over the lot and then pour fibre reinforced concrete - you’ve got a pretty well insulated slab along with a ring beam that is never going anywhere ..!

 

Just remember to duct in for the power and water !

[joe90]

Right, thanks guys for your suggestions, finally found local builder to lay the slab( for a resonable  price ), thanks to 

@Gus Potter for his suggestions (he is an S.E.), steel ordered and  boarding  for shuttering, hoping to lay in a couple of weeks (I work very slowly now I am ancient 🙄). On another note, i downsized the garage,  I was being greedy and left it tight to park my car alongside it so now 6m long by 4m wide, big enough for my toys!., pics to follow.

Edited June 7, 2023 by joe90

[SteamyTea]

14 minutes ago, joe90 said:

6m long by 4m wide, big enough for my toys!.,

Almost as big as my house footprint.

[Big Jimbo]

Good stuff Joe. Now get it done.

[Big Jimbo]

6 x4 will be a nice side for toys. Just don't fill it with junk. (like i would)

[Pocster]

I would have dug it down another 3 metres - but that’s me ….. 😎

[joe90]

1 hour ago, Big Jimbo said:

6 x4 will be a nice side for toys. Just don't fill it with junk. (like i would)

I already got rid of my junk when I moved house (but I know what you mean 😱) I gave my old cement mixer away and now had to rent one for a week 🤷‍♂️.