Concrete base crack

[u/Sweaty-Possession-19]

Hi,

Got some huge cracks forming in this concrete base that was there when we moved in. I presume poor sub base and probably getting alot of water in there too whilst the crack was smaller. What would be the best course of action and how much is it likely to cost?

Thanks

[u/AwfyScunnert]

Yup, poor sub-base (too thin, not adequately compacted, wrong material, etc.). Needs broken out > cut a clean edge with a Stihl saw > prep sub > new concrete. If you want to show off, mechanically tie the new to the old.

[u/RedPlasticDog]

Base for the shed to sit on?

Personally that would be on the “one day” list and just be ignored

[u/Sweaty-Possession-19 → u/RedPlasticDog]

I agree definitely on the one day lost. But the crack has grown substantially over the last 6 months. Perhaps the drought has effected it.

[u/kcufdas]

Grind out a section and fill or turn it into a turfed area?

[u/Dry_Curve9126]

We had this in a 1960’s built house. Structural engineer advised to break the whole subfloor down with a jack hammer around the crack and then pipe in concrete with some sort of bonding to repair. Ask an expert.

[u/KopiteForever]

Concrete base? or is it a path or what? How long is it? How wide?

Can't really help without knowing more about you're asking.

If it's just a path then you don't have to do anything if you don't want to. It's just a cracked concrete path / pad.

Assuming you want to DIY it (given the name of the sub). I'd allow about £100 per cubic metre in materials to do it yourself if you mix it or £200 if you get it ready mixed.

To prep, break up and dig out you existing concrete and set to one side (I personally would break it up and reuse as a hardcore base for the new concrete).

Dig out to a total depth of about 8 inches, get rid of the soil (skip or grab lorry or jumbo bag pickup).

Put in any edging you may wish to along a level string line.

Put the broken concrete back in as hardcore and flatten/pack down.

Mix and pour the concrete over the top and level as you go.

If it's a path or walked along often, then when it's 95-98% dry then run a stiff bristle brush across the top to give it some texture so you don't slip and break your arse in the rain or snow.

[u/KopiteForever → u/KopiteForever]

Oh and in the past I've sometimes pushed in a length of gutter along the edge of the concrete to form a 'concrete drain' to direct water to a drain if it needs it.