Hi Screwfix, I’m fitting my own kitchen and for the worktop am considering a DIY cast-in-place concrete slab using products from these guys (edge forms, suspended mesh, concrete additive, sealers): https://www.concretecountertopsolutions.com/ The concrete gets mixed with an additive to make it easily pourable. For the concrete the manufacturers (based in the USA) have told me I need: “Sand Mix which does not have pea gravel in it but if you cannot get something similar, a regular mix is fine” Anyone suggest some brand names / products of concrete here in UK which best fits that description? Cheers
You started a thread on this elsewhere on this forum. http://community.screwfix.com/threa...aking-a-concrete-worktop.184310/#post-1485270
My question about concrete above did form a part of a more general post on creating a concrete worktop, yes. However no answer on that specific question and realised more suited to this forum / audience. Thanks, D
We just don't use concrete worktops here in the UK much, compared to the states, where it's usually the preferred first option, & when polished & sealed they do look pretty impressive.
Presumably the aggregate used depends on the finish you want, the possibilities are endless. I've never tried this, but I know that getting the mix right, especially water content is crucial, as well as timing of floating/finishing. A friend has just had a bad experience with a polished concrete floor - the guy didn't get it right, and I think she's stuck with it now! I would probably do a trial run first, as you'd really want to get this right first time!
I'm going to use the products (including admix) from Countertop Solutions. They aren't able to advise on concrete brands as a USA company, I'm just trying to ascertain what they advise means for here in Blightly. “Sand Mix which does not have pea gravel in it but if you cannot get something similar, a regular mix is fine” Sand Mix, is that a thing over here?
Concrete is just a mixture of aggregates cement and water. For everyday concrete normally use ballast - 20mm stones down to sand, pea gravel is 10mm, sharp sand say 4mm or less, builders sand is pretty fine, and you can get finer sand as well. I would guess they're talking of something like sharp sand. But you can use any aggregate, just depends on the texture you want to get. Sand tends to vary from place to place, what is sold as sharp sand where you live might be a different colour/texture to what is sold in my neck of the woods.
Cheers for reply. Yes apparently aggregate needs to be under 3mm. I'm looking for ready mix I can buy in bags, any ideas as to any products that fit this bill?
Under 3mm is not far off a dense screed mix. How thick are you aiming for? Any reinforcement? Are you aiming for a floated finish or are you going to grind the surface to expose some aggregate? You could do worse than use grano
Thanks Stevie. Will be 30mm thick but with the system I'm using you suspend fibreglass messing within for strength. What's grano?
Grano is a fine 6mm - dust used for granolithic screed only used bonded to hard concrete slabs & fine granolithic concrete, can be polished. http://www.pavingexpert.com/grano_01.htm
Thank you all for your replies. Still not started as need to be 100% before going ahead. It would be great to have the manufactuer of the forms and admix (www.concretecountertopsolutions.com) reccomend a specific concrete brand / product to use, however understand that being based in the USA they won't be familiar for what we have here. As such I asked them about mixing my own from raw materials, here's what they said: "If you do want to make your own mix, you can combine 15 lbs of portland type I cement, 45 lbs of clean dry masonry sand, and one of our Liqui-Crete boxes. You do not need any larger stone as this does not give concrete strength. Some of the strongest mixes in the world only contain fine sand. The stone is a cheap and efficient way to help reduce shrinkage and increse compression strength slightly. If you do add stone or pea gravel there is nothing wrong with this but I would stay around 3 mm and I would have about 30 lbs of sand and 15 lbs of stone" Feel like I'm getting there! Last question then would be what is masonary sand? I have seen reference to 'sharp sand' and 'builders sand' and believe the former is used for screeding and the latter bricklaying. Therefore I assume sharp sand is what I require? Then do I need course sharp sand or fine sharp sand. Oh the confusion ATM here's what I'm thinking of going for: http://www.builderdepot.co.uk/fine-sharp-sand-40kg-bag-leighton-buzzard.html http://www.builderdepot.co.uk/hanson-castle-portland-general-purpose-cement-25kg.html Then the admix they refer to: http://en.diyconcreteworktops.com/product/43/z-liqui-crete-add-mix And presumably water (thought in what quantity the next question!) What does everyone think on my sand selection?
Masonry/ Mason sand is usually use in fine concrete,laying pavers,etc like a fine wash sand. Why not make a test worktop & see how it all comes together. http://www.braenstone.com/2013/07/concrete-sand-vs-mason-sand-vs-white-sand/
Thanks for reply Kiab, Yeah I definitely will but as ordering materials in bulk want to be sure I'm on the right track. So is 'Masonary Sand' what we would call 'Sharp Sand' over here, or do you get Masonary Sand over here? If so what is it? Cheers
A more of a fine wash sand, & we have many sands,a lot are regional. https://shbark.com/shop-g/mason-sand/ See this linky: https://www.cardigansand.co.uk/
Put another way do you have any reccomedations for what I should be buying here in the UK? I'd be especially grateful for weblinks/ "45 lbs of clean dry masonry sand" Cheers
For specialist sands I tend to us. http://www.aggregate.com/products-a...nd/specialist-sand-quarries/leighton-buzzard/
I see Lazenby use a C28/35 or C50 concrete which use a percentage of large aggregate in their worktop mixes. https://www.ribaproductselector.com...azenby-InsituConcreteWorksurfacesandFurniture
What is the look you are trying to achieve with a concrete top ? By the time you have bought all the concrete, form work, sealers etc. it may be the same price as a conventional or stone top. You are going to have to deal with the sharp, jagged and broken edges on both the top and bottom of the front edge and remove any bubbles or air pockets from the mix once it is in the formwork. Casting in place is very risky as any spills or leaks will be very messy and difficult to clean up
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