How to repair alfresco concrete slab gap?

[Sam12]

How can i align the bricks and concrete floor on this alfresco and whats the best idea to close the vertical gap as well

 

 

[MitchellMc]

Hi @Sam12,

A form structure will certainly be beneficial and help establish a neat edge. However, it will make it difficult to fill the area, so I suggest you do so in a couple of applications. For the first, fill inside and under the slab out to almost the front edge of the slab. Wait for this to cure before adding your formwork. You can then fill behind it, ensuring that the mix is pushed down into any gaps. Vibrating the formwork with an orbital sander can help the mix settle. Once the mix has set, you can remove the formwork and fill any voids or air pockets you missed.

Please let me know if you have any questions.

Mitchell

[EricL]

Hello @Sam12 

I would follow @Dave-1's suggestion and mix the grout firm. This means that you don't add too much water that it turns slurry. It would be like the consistency of peanut butter or very thick toothpaste. This will prevent it from slumping, and it will hold its shape. But if you feel that building formwork will help you with your project, I suggest doing a test build first to make sure that it does not fall or slide off when supporting the grout. 

If you need further assistance, please let me know.

Eric

[Sam12]

@Dave-1 do you reckon inserting an expansion foam rod or sika foam filler might help before adding the cement slurry to fill gap so it wont fall behind? Thanks

[Dave-1]

Evening @Sam12 

Going back through the question and answers I would try and head towards a firmer mix then a slurry. As you are concerned about it running down the back of the brickwork. Think of a pile of the wet concrete and how fast it would "slump" if poured in a pile. You really dont want it to slump too much so the mix will have less water in it. This way it should give a best way to push it into that gap and now flow through and down.

With teh expansion foam, If you think that the rear of the gap is fillable, you could try it but I suspect that its got a air drop behind the bricks. Thats a LOT of expansion foam  

Dave

[Nailbag]

Hi @Sam12 if you haven't used foam filler before, it does expand considerably and varies from brand to brand. A trick to help stop it from falling behind is to roll up some newspaper and press that towards the back first. Then apply a small row of foam across the paper and give it a few minutes then apply another row, this time you can apply more as required. Then as @Dave-1 suggests use a thicker slurry to a toothpaste consistency.

regards, Nailbag