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Posted: Wed Jul 11, 2012 10:26 am
by Cptstrathdee
I’m planning my first paving project and hopefully next week weather permitting (ha!) I will be laying a 2.16 diameter sandstone circle.
Having read the great advice on this website I just want to check a couple of things. To reduce the risk of staining I’m thinking of using snowcrete but I don’t want a white join so will it be okay to mix this with sharp sand to get a buff colour? Is there a cheaper alternative?
If I use a 3:1 ratio sand to cement does 10 bags of sand and 4 bags of cement at 25kg each sound about right (I’ve not done this before and it sounds a lot!).
Posted: Wed Jul 11, 2012 5:57 pm
by Pablo
Are you asking about the pointing or the bedding I don't fully understand the question.
Posted: Wed Jul 11, 2012 6:50 pm
by local patios and driveway
Sounds a lot to me, imagine putting down 2-3 bags of sand and brushing it in to the circle, you'll have some left over. 3 sand 1 bag cement should do the trick easy.
Also if you have a tidy technique and dont point up wet you should be fine. I like mine just damp enough that it holds together when compressed. Dont mess about with snowcrete etc.
Posted: Wed Jul 11, 2012 11:15 pm
by Thepinkpavingco
If you don't want white pointing don't use white cement and I personally would spend £20 on a pointing gun and use a wetter mix.
Posted: Thu Jul 12, 2012 12:36 am
by Carberry
Don't understand the question either, but if you are worried about the colour of the pointing then buy one of the premixed products like easypoint. If you try and dye it yourself it will fade within a year
Posted: Thu Jul 12, 2012 9:01 am
by Cptstrathdee
Thanks for the advice - I think I'll use something like Easipoint for the pointing but what I really want to know is how much mortar should I use to lay the paving and whether I should use a light coloured mortar as the paving is sandstone - if I use something like FlexibleSlab Fix would there be a risk of discolouring?
Posted: Thu Jul 12, 2012 10:51 am
by r896neo
Don't use flexible slab fix you need a rigid bed. 3:1 is OTT
Use 4 or 5:1 grit sand/ plastering sand : Cement.
No need for white cement under it, Standard Portland is fine.
Use the mortar calculator here to figure out quantities although you don't sound way off.
http://www.pavingexpert.com/calcall.htm#focus15
Posted: Fri Jul 20, 2012 11:14 am
by mnlad743
Carberry wrote:Don't understand the question either, but if you are worried about the colour of the pointing then buy one of the premixed products like easypoint. If you try and dye it yourself it will fade within a year
I'm afraid I've got to disagree with your statement "If you try and dye it yourself it will fade within a year" if you are referring to powdered cement pigments that are mixed into a wet mortar, concrete or render. If on the other hand you actually mean a liquid (acid or polymer-based) concrete dye - you could well be right, I've got no experience with those.
There is no reason at all that powdered pigment, when used properly, should 'fade with a year'. Not unless they are an extremely poor quality pigment or the wrong type for use in cement-based materials.
For instance, some people will try to use carbon black pigments in concrete because they are a much cheaper pigment than an iron oxide type. Carbon black will wash out of the surface and yes their effect will disappear with time.
Likewise, most types of blue pigment cannot be used outdoors or in interior locations where they may be exposed to direct sunlight because they are not only UV sensitive but also because the various acids present will attack the pigment (this problem can only be avoided by using cobalt blue pigment, but you had better be sitting down when you see the price).
Posted: Fri Jul 20, 2012 12:24 pm
by local patios and driveway
Ive tried black powdered dye for pointing. It looked dull after 6months. Was a pig to cut out and replace.
Posted: Fri Jul 20, 2012 10:06 pm
by lutonlagerlout
mnlad743 wrote:Carberry wrote:Don't understand the question either, but if you are worried about the colour of the pointing then buy one of the premixed products like easypoint. If you try and dye it yourself it will fade within a year
I'm afraid I've got to disagree with your statement "If you try and dye it yourself it will fade within a year" if you are referring to powdered cement pigments that are mixed into a wet mortar, concrete or render. If on the other hand you actually mean a liquid (acid or polymer-based) concrete dye - you could well be right, I've got no experience with those.
There is no reason at all that powdered pigment, when used properly, should 'fade with a year'. Not unless they are an extremely poor quality pigment or the wrong type for use in cement-based materials.
For instance, some people will try to use carbon black pigments in concrete because they are a much cheaper pigment than an iron oxide type. Carbon black will wash out of the surface and yes their effect will disappear with time.
Likewise, most types of blue pigment cannot be used outdoors or in interior locations where they may be exposed to direct sunlight because they are not only UV sensitive but also because the various acids present will attack the pigment (this problem can only be avoided by using cobalt blue pigment, but you had better be sitting down when you see the price).
you can disagree till the cows come home bruce
the one eyed man is king in the real world :;):
the only colour i ever saw that was fast is when we brought red sand off cemex and mixed it ourselves
show me proof off a dye working long term and i will convert
all the best
LLL 
Posted: Fri Jul 20, 2012 10:26 pm
by ilovesettsonmondays
pointed round some boxes last sunday using black dye ,today the colour is light charcoal.use easipoint but dont use natural dries too grey.
Posted: Fri Jul 20, 2012 10:55 pm
by r896neo
A lot of houses over here in NI are built with acheson glover fergustie and other coloured bricks. They are most commonly layed with a dark brown mortar and the powdered colouriser is very effective. I have mixed some up myself and its a completely different beast to normal crap.
Of course these are mainly vertical walls and will never get the same weathering but even on closer courses on top of garden walls where it is a horizontal surface it does not fade. 15 years on from building they are still the same colour.
It was an iron oxide based pigment fern....something and bloody dear, about 90 quid for a 25kg bag but that would most of a house.
Posted: Mon Jul 23, 2012 9:45 am
by mnlad743
lutonlagerlout wrote:
you can disagree till the cows come home bruce
the one eyed man is king in the real world :;):
the only colour i ever saw that was fast is when we brought red sand off cemex and mixed it ourselves
show me proof off a dye working long term and i will convert
all the best
LLL [/quote]
First I'd tell you to have a look at any Marshall's, Bradstone, etc paving slab. All of these are manufactured using powdered iron oxide pigments as are concrete roofing tiles and concrete block pavers - and that's the short list. There are pigments available for the low volume user which are identical in quality to those being used by the high-volume manufacturers.
My point, and I must admit that I may not have made it very well, is that most people who have had problems using pigments have self-inflicted those problems. Either they've bought a powdered pigment without knowing how to use it or they have purchased a poor quality product or a product not designed for the application in which they intend to use it.
Posted: Mon Jul 23, 2012 9:52 am
by mnlad743
ilovesettsonmondays wrote:pointed round some boxes last sunday using black dye ,today the colour is light charcoal.use easipoint but dont use natural dries too grey.
Pigments are not as easy to use as one might think and Black is one of the most difficult pigments to use of all of them. It requires a higher pigment concentration than most of the other colours (6-8% of cement weight vs 4-6%). Did you do any testing at different pigment concertrations prior to going ahead with the final stage to see what the colour was after the mortar reached a full cure?, you cannot rely on the colour of a 'wet' batch it always looks darker.
Posted: Mon Jul 23, 2012 9:57 am
by mnlad743
r896neo wrote:It was an iron oxide based pigment fern....something and bloody dear, about 90 quid for a 25kg bag but that would most of a house.
Actually 90 quid isn't bad as pigment prices go. Thay can vary from something like £60 for a York Buff to about £210 for a Strong White. Then you get into the more exotic colours, £1700 for a Cobalt Blue (the only blue you can use out of doors or in direct sunlight) and recently I've seen a Lilac that comes in at a whopping £2109.