How to make a concrete countertop larger?

[beemerx65]

hi I’m wondering if I’m able to make my current top about 2 inches wider on the front & side edges for more overhang maybe another 1/2 inch thicker all over to seal & polish better as bbq stains or would it be easier to remake ?? 🙄👍👍

[Dave-1]

Evening @beemerx65 

Mmmmm finding it hard to picture your current concrete countertop Any chance of a few pics, an overall one, some side profiles and maybe one showing where you want the overhang to be extended? 

Dave

[beemerx65]

 

 

 

 

[Dave-1]

Evening @beemerx65 

Love that countertop Not sure how thick it is. I am starting to think that it may be easier to construct a new one then modify this one. Mostly because I dont know how you could bond the new part to the old part with enough strength to support the weight. And that just raised anther question, what supports the current concrete bench top?

Thinking outside the square, I wonder if you could give the whole bench a hardwood timber edge? That way you could expand it out without having to concrete it.  I am thinking of something like this 135 x 19mm L/M Decking Ironbark KD Standard Maybe not all four sides, but the front three sides. I went for a lighter hardwood comparedto the usual Merabau as I think it would look great next to your concrete. How bad are the stains on the concrete?

Dave

[JacobZ]

Hi @beemerx65,

Thank you for your question about extending a concrete countertop.

As @Dave-1 has said, it would be very difficult to attach concrete to the side of your countertop in a way that would bond well, be supported and look nice.

Unfortunately, if you wanted an extended countertop made entirely of concrete, you'd need to start again.

If you want to attempt to pour your own, you might like to check out How I poured my concrete kitchen countertops from @mcscc for some inspiration.

If you weren't confident pouring your own countertops, I like Dave-1's idea of attaching some hardwood as an edge band. This would give you that little bit extra space, while still maintaining a nice look to the countertop.

Let me know if you have any further questions.

Jacob

[beemerx65]

Thanks for your help. I’m ok with pouring another slab as in mcssc  page. I noticed that dingo high strength concrete was used with an extra cup of cement. Unfortunately dingo concrete is not available in WA ?? 
cheers 

[EricL]

Hello @beemerx65 

If the Dingo brand is not available in your area, you can also try Easy Mix 20kg 55MPa Super Strength Concrete or the Westbuild 20kg 40MPa Concrete40 High Strength Dry Mix Concrete. But I don't recommend getting anything lower in MPa strength. 

I suggest speaking to your local store’s trade specialist, as they will be familiar with high-strength concrete and might be able to offer other alternatives.

If you need further assistance, please let us know.

Eric

[beemerx65]

Hi. I’m ok with pouring my own as I did originally. Am I able to add a bit more water to the concrete mix to make it more easier to pour into the mould whilst maintaining strength & ability to remove air bubbles?? 
thanks 

[JacobZ]

Hi @beemerx65,

I wouldn't suggest adding extra water to the mix as it dilutes the cement which reduces the bond between the cement and aggregate. In turn, this will reduce the strength of the concrete.

It's best to follow the manufacturer's guidelines for mixing ratios as this will ensure you are getting the strength they have advertised on their product.

My suggestion is to set your forms on a nice level surface and grab a rubber mallet to tap the side of your forms. The vibration this will cause will help to settle the mix, remove any air bubbles and ensure there are no voids.

Let me know if you have any questions.

Jacob