Garage base - advice pls

[S47]

Contemplating demolishing my existing garage and enlarging it,which would mean I'd need to dig up existing slab and relay to the larger size.
What thickness of concrete will I need, and will it require reinforcing with steel, and if so what size mesh would I need.
New garage size will be 6x5.5M, built from concrete blocks, with a single pitch steel roof.
Thanks

[herbialfa]

150mm concrete slab with a layer of A134 mesh 50mm above the datum!

[Si 330]

I haven't A134 fabric haven't come across that size.

Edited by Si 330 on Thursday 14th October 12:01

[rovermorris999]

For the small extra expense consider bunging in a damp-proof membrane, it'll help keeping the condensation down.

[The Black Flash]

rovermorris999 said:

For the small extra expense consider bunging in a damp-proof membrane, it'll help keeping the condensation down.

^^^ Definately this ^^^

Definately. Otherwise you'll have trouble (read, more expense) painting it etc.

[S47]

Thanks for the replies
Yep forgot to mention the DPM I intended to use that.
What exactly does A134 mesh mean in sizes? My local builders only have A142, which is 6mm gauge 3.2x2m/sheet size - anyone know the differences?
THX
Mal

[Si 330]

There is no such thing as A134. A142 is 6mm bars at 200cts this will control cracking in the slab. I tend not to specify A142 as I don't like using 6mm steel so as a min I would spec A193.

[Fume troll]

Mine says:


But then the walls don't stand on it...

Cheers,

FT.

[Si 330]

100mm thick slab leaves you a little thin on cover to the reinforcement.

There is a house builder we have worked with for years he always moans that garage slabs are specified at 150mm thick. He thinks they should be 100mm, last year we designed his own house he requested that the garage slab be... 150mm thick.

[Spudler]

Ring your concrete supplier and ask if they do Fiber Reinforced Concrete (FRC), it saves messing about with sheets of reinforcing.
Thicken up in the doorway as mentioned in the text above.
Put a little thought as to where the door will sit when closed and you can form a raised lip behind the door to stop any rain working its way into the garage.
If your going to paint the floor you'll need to finish with a steel float by hand or power float.
When ordering the concrete ask for a "garage floor mix", smaller stones and much easier to float.
Personally i'd go 150mm thick.
Some of the below links may make life a bit easier.

http://www.brandontoolhire.co.uk/directory/prodvie...
http://www.brandontoolhire.co.uk/directory/prodLis...

[S47]

Si330
Thanks for the reply - whats the difference A193 to A142 mesh?
The whole floor area 5.5 X 6metres is large area is it better to put a leveling shutter accross the middle [sorry if its a dumb Q, but this'll be my first attempt at laying concrete;-)
so get the floor nice and flat in the centre
THX
Mal

[Si 330]

A193 is 7mm bars at 200mm centers in each direction, 193 refers to area per mm2.

Standard sheet size is 4.8m x 2.4m a 300mm over lap of each sheet will fine.

If you don't have some timber to use as formwork you can hire road formers.

[rovermorris999]

Have you thought about Onduline or similar instead of steel for the roof? It'll outlast steel, be quieter when it rains and cause less condensation.
Smells lovely too but you may get some odd looks if you sniff your garage roof.

Edited by rovermorris999 on Friday 15th October 12:29