How to make a stunning worktop from concrete!

What an interesting post, James; I don't know how you find the time...

I once did a course at Boscastle with Carole Vincent, a well known sculptor of concrete public installations:

http://www.carolevincent.org/majorworks.html and I'd like to add a couple of tips that I learned to your blog that may be helpful:

Carole kept very detailed records of mixes using many forms of "fines" and aggregates. We tend to make yer average, bog standard concrete with say: 1 of cement, 2 of sand and 3 of gravel - all depending, etc. Whereas Carole would list - from dust to, perhaps, 15mm stone, TEN different grades in certain relative quantities to ensure there were NO spaces whatsoever. A lot of it was marble. My point is that she wanted the final thing to have no air bubbles at all: it was just like marble. So, a bit of experimenting with those ratios from dust, through different sized particles, to lumps, plus use of stuff like white cement, can give interesting variations.

The other thing was a self-compacting additive that she liked to call "her secret ingredient" but, aha! I found out what it was - and will now share:

Advaflow 340 http://www.resapol.com/datasheets/data265.pdf brilliant stuff and next to no compacting needed if used correctly. There may be an upgrade to this now as that was a few years ago now.

Have fun!

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Thanks John :)

Hi James et al. the densifier does exactly what it says in the name it makes the concrete in the first 5mm or denser by causing a chemical reaction between the silica of the densifier and the lime of the cement. It also seals up the tiny pores in the concrete making it harder and therefore easier to polish. It was a while back I did this and I had to look to the USA for the information and products apart from one company I found later in Earls Court. A great resource is this lot: http://www.concretenetwork.com/densifiers/

It looks like things have moved on a bit now as they have nano particle densifier as apposed to the ordinary lithium silicate based product I used.

As Mrs Mop, I can vouch for the bathroom floor. It is v easy to clean, doesn't show the dirt and looks fab. Everyone loves it!

ps John and Tracey - any chance of a photo of you lovely people please? Thank you!

John, can you post a link to the densifier product please? What does it do?

Yes Tracy, you can do polished concrete floors too, here's one I did earlier :) http://www.survivefrance.com/profiles/blogs/polishing-a-concrete-floor

Bryan I would prefer not to bugger you but please people send off for a densifier or you will not enjoy these. Yes Tracy it is frequently used as a floor. Specialist companies with large floor polishers though not a little hand one.

Could you do a floor with this finish too?

You're welcome Bryan! The tricky part for kitchen worktops is what to seal it with, without it costing a fortune. There is a guy on SFN that supplies such products, I've discussed it before with him. I can't remember his name for the moment though :(

Well bugger me what a great idea,and it looks great,for me as i am about to start installing a kitchen and worktops are on the shopping list,now i think it will be ballast,cement and colouring.thank you james

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Actually this is one of the things I love about living here. The time and space to create the home you really want.

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Well I have been looking into how to polish concrete - so a v timely post!

Thanks James - loving the DIY projects - keep 'em coming.

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What they call Beton Cire here is actually a liquid cement based product that you pour/trowel on to a suitable substrate. it actually has nothing to do with wax (cire). And it's really expensive! I just priced up using some from Leroy Merlin and it worked out at 40 euros per square meter, it's very popular now which is probably why it's so expensive. I bought a really lovely tile instead for 30 per sq meter, and I'm pretty sure that will be more durable too.

I thought you made it look easy! I had to make one some years back for a customer and obtained said densifier by mail order which produced a much harder denser surface. We finished that with beeswax to seal and polish. In france I believe it's called beton cirre?

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HI John, it's not my first attempt! I haven't tried adding a densifier, I think the concrete would still be prone to acid attack from citrus fruits and wine etc. For kitchen use where spills of that kind are likely, I would use a topical or penetrating sealer. The topical products are extremely hard wearing, the downside being the price and the loss of the tactile nature of the surface. The penetrating sealers will need to be applied regularly.

James

Nice first attempt but I didn't see you mention the addition of a densifier to the mix/or afterwards so the concrete will be too soft and porus for a kitchen worktop.

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@James - as interesting as this topic is - is it correct that this topic has the highest number of views at over 32,000 on SF?

(I have to admit having a background in Civil Engineering from many years ago - concrete is very exciting stuff!)

It does have the highest number of views yes! It’s actually closer to 250k as the view count was reset when we moved to new software last year.

I think this shows that there’s not enough really helpful, relevant, step-by-step DIY stuff on SF, and that people on SF find value in this topic. We need more DIY discussions, and please, more on what you and others have done with concrete… And wood… And stone… And everything else.

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