Colour fading in concrete blocks - Which concrete blocks are colour fast ?

[georgeb]

Looking at existing driveways, I see that many have lost most of their colour even after a short time. Although the sun will tend to cause some fading over time it seems that some driveways are worst than others.

Are some block types or suppliers better than others ?

If so, which blocks / manufacturers are recommended and which should be avoided ?

Is block colour covered by any of the suppliers guarantees ?

[Tony McC]

have these driveways really lost their colour or have they just become dirty? The layer of crap and crud that always accumulates on paving can mask a lot of the colour, but, if the blocks are properly cleaned, they'll be as good as new (almost).

However, some blocks from certain manufacturers are less fade-resistant. It's purely subjective, and I'm sure other contractors will have their own thoughts, but for me the most fade-prone blocks I've ever used as Plasmor Widnes. Marshalls are, generally, pretty good, as are Tobermore, Brett and TopPave. Less sure about RMC, Eaton and Charcon.

And as you could probably have guessed, colour-fastness is not guaranteed by any British or Irish manufacturer, although one Belgian manufacturer does guarantee the colour of some of the products.

[mrcw]

I have durapave budget blocks 50 mill, south facing patio area, and still look good 4 yrs on

[georgeb]

Tony,

We were thinking of using Marshalls brindel excel block for our driveway as we liked the style and colour variations.

However, we have seen a brindle excel driveway which was installed about six months ago.

There are two brindle octants in the middle of the driveway. These still look good with interesting colour variations but the surrounding blocks look completely bland with very little colour or colour variations. You would not even know that the colour was brindle by looking at the surrounding blocks !!

I don't know if these blocks were pale when first installed or just faded quickly when exposed to the sun.

The octants in this case obviously come from a different batch, or factory, compared with the standard blocks.

Presumably some batches have been made to a different recipe or have got through poor quality control ?

Is there any way of ensuring that a good batch of blocks are obtained ? Are the 'Ramsbottom' blocks always of good quality, for example ?

George

[Tony McC]

The colour diff between the Excel Octagon and the 'standard' Excel blocks is most likely due to them being manufactured in different plants, just as you suspected. Marshalls have a number of plants dotted around the nations and each plant tries to use local aggregates as far as possible. Different aggs produce different concretes that respond differently to the cement dyes used to colour the blocks. This is part of the reason why the Ramsbottom plant, nestled in the Pennine Hills north of Manchester, makes such wonderful brindle blocks while those from, for example, Sandy are, to my eye, somewhat less appealling.

Unfortunately, blocks tend to stay in the area where they were manufactured, so Rammy blocks tend not to turn up in, say, Sussex. That's not to say they never turn up down there - if there was a surfeit of production at Rammy, or a dreadful shortage in the south, blocks will be transferred to meet demand. Also, as mentioned, 'specials', which includes the octagons, kerb and channel units, etc., tend to be made at one or maybe two factories and distributed nationwide: it makes economic sense to do so.

It's not just Marshalls that work this way - all the manufacturers with more than one site play the game in the same way, so RMC, Charcon, Plasmor, etc., also manufacture 'specials' at one plant, and standards at many.

So: your location is likely to detrmine which blocks you get. You can insist on blocks from a specific plant, but you will have to pay for haulage and admin, and you can guarantee the local BM will be totally unhelpful in the way only they can when asked to do even the slightest thing out of the ordinary.

Have a look at local drives: call in at local BMs and take a peek at the packs they have in stock; consider using an alternative to the Excel - use the more reliable octagons by all means, but think about using, say, Tegula Drivesett as the 'main' paver, or use a perimeter course of, say, Chapelgate clays or plain 200x100 blocks in a contrasting colour, to emphasise the delineation of the octagon(s) from the rest of the paving. such a strong delineation can help mask the fact that there's a difference in tone between the two areas.

[georgeb]

Thanks Tony

I'll try and see how difficult it is to get Rammy blocks in Edinburgh. As we did not plan to include any octants, we were faced with the prospect of having a completely bland driveway if the wrong blocks were used.

Incidentally, Marshalls have opened a new display site next to their plant in Falkirk which is probably the source for most local supplies. When we looked round, our first reaction was that most of the block colours were pale versions of those in the catalogues (with the possible exception of volcano). As you suggest, the local aggregates may not 'take' the dyes well.

George

[Tony McC]

I'm not sure what aggs are used at Falkirk. IIRC, it was a granite or whinstone and a granitic or river-dredged sand. These hard, igneous aggs seem to"resist" colouring more than some of the relatively softer sedimentary rocks, even though there shouldn't be much of a diff as it is supposed to be the cement that is coloured by the dye, rather than the aggs. However, concrete is such a complex and variable 'product' that we just have to accept that different aggs make for different colours.