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Tim JA
Tim JA, Construction Worker
Category: Home Improvement
Satisfied Customers: 2448
Experience:  Owner at Self-employed
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We have just had a concrete foundation poured and the slab

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We have just had a concrete foundation poured and the slab looks shiny, oily, lumpy and is cracking in places. Is this usual or unusual and is there anything in what I have said to be concerned about? Why would concrete footings look shiny / oily? And after two days, cracking in places. Thanks
JA: What specific appliance or part are you working with?
Customer: Not an appliance
JA: How long has this been going on? What have you tried so far?
Customer: Just noticed it. Haven't tried anything yet.
JA: Anything else we should know to help you best?
Customer: We need a professional to let us know what to do, if anything.

Good afternoon, and welcome to the Technical section in JustAnswer, an independent paid question and answer platform that matches customers' questions to experts in various skills. My name is ***** ***** I'll be happy to help you today.

I will need some detail from you before I can give any opinion, so I have lots of questions:

1. What depth of slab?
2. What area?
3. What quantity of concrete?
4. Readymix, or mixed on site?
5. If Readymix, what specfication?
6. What day & time was it poured?
7. Can you attach a photo of the part(s) that look wrong to you?

_____

There's no time pressure on this topic - it will stay open to you for many days, and you can reply at any time. I will be away from my desk sometimes, but will respond as soon as I can.

Customer: replied 16 days ago.
1. Depth: 300mm Strip foundation of 6m each x 450mm wide
2. UK
3. No idea, contractor arranged
4. Was poured by company on site
5. No idea
6. Couple of days, time 12:00 midday
7. Yes, how do I do that on here?Thanks

Please see the following guidance on attaching photos:

https://www.justanswer.com/help/how-do-i-send-photo-or-file-expert

It has been extremely hot this week, so it's possible that the mix became too hot, and/or set too quickly. Did the contractor use a retardant? Did they provide shade for the surface of the concrete, and/or arrange to keep the surface moist?

See the following web site which gives you some insight into the precautions needed when pouring concrete in hot weather.

https://www.totalconcrete.co.uk/news/guide-to-pouring-concrete-in-hot-weather/

Customer: replied 16 days ago.
No they didn't mention anything afterwards so we just assumed it was done. No idea about retardant or anything about it at all. Should we be concerned? Here are some pics.
Customer: replied 16 days ago.
Does it all need to be removed and redone? Or can we fill the cracks with dried cement?

Judging from these photos there's absolutely no problem. The crack in one of the photos is tiny and will have no consequence. I would not to anything to it - leave it to your contractor.

Is this building work being routinely inspected by your local BCO?

Tim JA and other Home Improvement Specialists are ready to help you
Customer: replied 16 days ago.
Many thanks for the info, it is peace of mind.
Have a lovely evening.

You're welcome; I'm happy to have been of help :-)

Thank you for your rating, and your kind bonus.  I'm glad that I could help.
I hope you enjoyed your experience with JustAnswer.
Have a wonderful week :-)