DIY screed - 5-6m2

[Moonshine]

I have a small area of floor that wasn't screeded at the same time as the liquid screed for a number of reasons.

Its about 5-6 m2 and want to take on screeding myself with a laser level, as no ufh going I'm this area

Probably looking at a sand and cement mix.

Any tips / min depths?

 

[Jenki]

I'd say a screed would be minimum 50mm to reduce cracking, grit / sharp sand and cement 4:1 / 3:1 ratio with some form of plasticiser, but surely your FFL will dictate the depth?  its not a massive area so may be Self leveller would be an option.   SBR bond the sub surface?  - what is the sub surface?

[markc]

You don’t need a laser level at 5-6m2 .. a spirit level on a tamping board is all you need

[PeterW]

Screed or concrete ..?? 
 

Screed gets laid semi-dry and tamped into place and smoothed, concrete is laid wet and then floated. You can walk on concrete the day after, screed needs 3-4 days ideally and then care needs to be taken for another week or so.

 

Depending on depth and how long you’ve got or can wait, then concrete with a thin SLC layer is usually the easiest to DIY. It flows a bit better and you don’t end up in the situation that you need to work on it to finish it unlike a screeded surface. 
 

I’d want 80mm min for concrete, little bit more for standard sand cement screed. At 80mm, you’re just less than half a cubic metre or around a tonne of concrete. A volumetric mixer would drop that in 10 mins, it’s about 8 wheel barrow loads and you’ll have it levelled off and tamped within an hour. All you need is a batten on each wall to run a level board down and it’s done.

[jayc89]

My first foray into screeding was a 9m2 room. 60mm deep. Ended up mixing the screed myself as ordering in such a small quantity was cost prohibitive, mixing it was an art in itself, needs to be dry-ish (snowball test) but too dry and it sets crumbly. It's DIYable but not something I fancy doing again in a hurry. Cider went down surprisingly well that night... 

[twice round the block]

Hardest part is trying to get the stuff out of the mixer drum. The more loads you do the worse it gets.

 

Good alloy straight edge and wooden float works wonders After putting down a row of screed around the edge of the room and one down the middle, fill in the voids to the level... easy for old school... non of this pump slurry. 

[saveasteading]

Lots of people can lay concrete to a decent standard, so you probably can too, using the advice above.

Very few can do a dry screed. I watched 1000m2 being laid over the course of a week. The  guy was on his knees all day. Amazing workmanship, but usually unnecessary.

Keep it on the dry side and it won't crack. I would add some fibres for the £5  investment but it isnt necessary.

[Nickfromwales]

15 minutes ago, saveasteading said:

Lots of people can lay concrete to a decent standard, so you probably can too, using the advice above.

Very few can do a dry screed. I watched 1000m2 being laid over the course of a week. The  guy was on his knees all day. Amazing workmanship, but usually unnecessary.

Keep it on the dry side and it won't crack. I would add some fibres for the £5  investment but it isnt necessary.

Fibres every single time. A no-brainer afaic.

 

Why not make this a pissy mix of 6mm aggregate concrete all-in? Lots of shouting at it and it'll practically lay itself.

[saveasteading]

2 hours ago, Nickfromwales said:

Lots of shouting at it and it'll practically lay itself.

Is that copyright?

 

2 hours ago, Nickfromwales said:

add some fibres for the £5  investment

Moonshine, it is available at Wickes or online.

For avoidance of doubt, these are tiny hair-like plastic fibres, not the steel variety used for runways.

They are simply sprinkled into your mixer, or into the concrete truck on a larger scale.

[Mr Punter]

I really like sand / cement screed laid by a pro.  I would not tackle this myself.  Get the plasterer to do it and you on the mixer / barrow.