Concrete slab - cracks along mesh

[Adam sarwar]

Hi I've had a concrete slab poured in my house 2 days ago by a company and levelled by some builders. I will be insulating further and screeding on top for a wet ufh. I don't think the job was done too great for as I have 3 issues

1) I had some A242 (6mm) mesh placed in the floor of my 100mm slab, and in 2 places it seems to have fallen off the spacers and is slightly sticking out the concrete slab. As pictured. I didn't see this as an issue however I have noticed slight cracks are starting to develop around the mesh as you can see in the pictures. I don't want the floor to fail, under the UFH screed, what would be the best course of action. I was thinking of angle grinding that section out and having bonded concrete poured in to fill the void. Thoughts?

2) in one room, some of the expansion strip managed to come out in 2 areas, the room perimited is about 20 metres, the expansion strip has come out for around 2 metres in total. Will it be fine or do I need to angle grind a new gap in

3) the concrete doesn't have a smooth finish, it's level throughout the floor however it's quite bumpy all over. I was told this isn't an issue as it's only a sub floor, the final finish will be a 75mm sand and cement screed. What are the thoughts on this?

 

[dontbelieveawordofit]

6mm mesh in a 100mm floor.
is this as per your buildings approval?

 

[Mr Chibs]

I'm curious to see the answers, as I'll be having a floor layed soon.

I'm not going with mesh, I too with be having 100mm PIR, UFH and screed on top.

I would guess if it's bumpy you'll either need to grind or choose to leave and compact the insulation to form around the bumps. Was much time spent troweling to floor flat? or at all?

 

[Adam sarwar]

6mm mesh in a 100mm floor.
is this as per your buildings approval?

Yes 6mm A242 mesh. I wasn't actually required to have mesh in my slab I done it as an extra precaution, how would you have done it?

 

[Mr Chibs]

I was under the impression that reinforcement was not needed for most residential slabs.

I’ve recently read of brushing in cement (dry) into the crack. The residual damp in the slab will wet the cement.
Never tried it, but I will if it happens.

my know it all neighbour Says add a contraction strip, (Wooden batten) to induce the crack, remove said batten Then fill in the channel it created, thought is the crack will form along thinnest section.

As you are screeding, don’t think I’d be worried about the cracks You have shown. Are you laying your own screed or buying it in?

 

[dontbelieveawordofit]

Yes 6mm A242 mesh. I wasn't actually required to have mesh in my slab I done it as an extra precaution, how would you have done it?

never used mesh in a house floor.