Garage floor question- thickness of screed

[Emsman]

Dead simple-a friend is about to build a garage.

What thickness of screed should he be looking at?

Would 300mm of crushed rubble, covered with a 200mm screed be sufficient for normal cars etc??

Anyone who has built one that can offer a solution??

Greatly appreciated

[Busamav]

He doesnt want screed , he wants concrete

[Spudler]

As above.

Tell him to compact the hardcore in layers, not all at once. 200mm is more than enough, just thicken it up at the door opening.

[Emsman]

Sorry chaps- concrete slab, powerfloat finish.

[Spudler]

Emsman said:

Sorry chaps- concrete slab, powerfloat finish.

Must pour it first thing in the morning or he'll still be floating up at 2 o'clock the the following morning. Pour wet and use a poker. Hire this: http://www.brandontoolhire.co.uk/directory/prodvie...

[Busamav]

I would also throw in a damp proof membrane under the slab for what it costs .

Is he digging a pit ?

[Emsman]

Already got 1000 Gauge for the Dpm thanks.
He aims to dig down 800 mm to work levels off an existing floor

Eta no pit though, just a solid floor

Edited by Emsman on Saturday 11th September 12:33

[Emsman]

Already got 1000 Gauge for the Dpm thanks.
He aims to dig down 800 mm to work levels off an existing floor

Edited by Emsman on Saturday 11th September 13:07

[Zip106]

If he's power floating it and wants to paint it afterwards he'll have problems unless he acid etches it or scabbles it when it's dry.

To me, power floating is THE worst thing on concrete when people want it painting!

Just worth noting.

Edited by Zip106 on Saturday 11th September 15:21

[normalbloke]

I thought garage floor paint was sooooo yesterday and tiles were the way forward!

[dave_s13]

Zip106 said:

If he's power floating it and wants to paint it afterwards he'll have problems unless he acid etches it or scabbles it when it's dry.

To me, power floating is THE worst thing on concrete when people want it painting!

Just worth noting.

Edited by Zip106 on Saturday 11th September 15:21

Can you expand on this as my neighbour has recently poured and powerfloated his garage floor only to be told he can't paint it for circa 5 months. Needs to allow 1 month of drying out per inch of concrete or something? The paint will fail/peel if put on now apparently.

[caziques]

dave_s13 said:

Zip106 said:

If he's power floating it and wants to paint it afterwards he'll have problems unless he acid etches it or scabbles it when it's dry.

To me, power floating is THE worst thing on concrete when people want it painting!

Just worth noting.

Edited by Zip106 on Saturday 11th September 15:21

Can you expand on this as my neighbour has recently poured and powerfloated his garage floor only to be told he can't paint it for circa 5 months. Needs to allow 1 month of drying out per inch of concrete or something? The paint will fail/peel if put on now apparently.

An inch a month is about right, in metric countries it's 1mm a day, to let all the water dry out. Only paint after this.

[Zip106]

The drying times noted above are correct, but this isn't so much the problem.

The problem with power floated floors is that when they're floated all the laitence (weak, dusty cement particles) rise to the top.

If paint is applied to this, even a very thin 1st 'mist' coat, then it won't adhere.
The laitence eventually wears off along with the paint and you're left with a very ste looking floor that needs the paint removing before making good to re-paint.

Okay, you can get a very nice finish with power floating but once dry you must either acid etch it or mechanically scabble it - that is, to remove the top surface prior to painting.

This is a very informative site - http://www.icipaints.co.uk/support/specifications/...

Acid etch - http://www.decoratingdirect.co.uk/viewprod/t/TORAE...

I've had problem floors where I've had them scabbled AND etched and still the painted finish, to me, wasn't really acceptable.


Have you thought about DynoTiles?

[Spudler]

Maybe im missing something here, if the powerfloating is done correct why would you want to paint the floor?
BTW, 1mm/day drying time is based on screed which is semi dry. If your powerfloating it needs to be wet, which should be taken into account.

[MATTP77]

Spudler said:

Maybe im missing something here, if the powerfloating is done correct why would you want to paint the floor?
BTW, 1mm/day drying time is based on screed which is semi dry. If your powerfloating it needs to be wet, which should be taken into account.

agreed.