Algae in the new pointing - Algae pointing

[trixsimtb]

Having recently (May 08) had a new patio laid, in a South West aspect so it gets any sun thats going, the pointing just never seems to dry out and now its green with algae and a brown rust colour to half of the pointing (some has dried out) but is this to be expected from a new laid patio 3months old and sits in the direct sunlight from 11am till dusk? and if so how am I to remove it and I still don't understand why 90% of hte pointing doesn't dry out? this was an expensive patio not a cheap job, a Marshall registered job

[Rich H]

Pointing often looks like that in the first year - damper than the slabs it's jointed to. This is while the cement is approaching fully cured. While cement hardens quite rapidly, it can take months to set fully.

As for the algae, we've had the wettest year I can remember. I don't care what the meteorologists say, I know how many days I've lost! It's more than previous last five years put together. The damp & warm conditions are perfect for algae.

If the pointing is still sound, i.e. not crumbling, then the chances are that it is fine. Clean off the algae with a brush and hose and look forward to that consistent and evenly dry look next summer!

[trixsimtb]

This great you have made me feel a whole lot better especially as it cost me a lot. The slabs dry out as soon as the sun is on them its the cement. i'm curious I understand the Algae as its green coloured but its strange that some of the pointing looks like a deep rust coloured, guess its a different type of algae? Hot water and soap it is then, though I did try this on a small sample and didn't make too much difference, guess scrub harder. Is it worth trying to seal the pointing or is sealant just for for the block paving driveways?, sorry to ask soo much, but very pleased I got a prompt reply

[Rich H]

You can seal most types of paving, although it alters the appearance quite a lot. If you look on the main website you'll find a good deal of info about sealing and sealants.

In my opinion, I'd rather keep the natural look but maintain it regularly with a good clean.

The deep rust colour you describe in the pointing; do you have a photo you could post.

Just one more thought. Patios under mossy roofs will go greener, quicker. Moss, lichen and algae spores, etc., will migrate from a roof to new paving very quickly.

[trixsimtb]

I will get a photo to you tomorrow (if I can work out how to attach one!) the patio is in direct sunlight from 11am, there are no trees, no mossy garages etc, that was the reason I thought it strange. I really do appreciate your advice on this, I was only thinking of sealing the pointing not the slabs don't think that would work, they are Saxon Buff and it would probably chip off (okay chip might be the wrong word but if you know the slabs I'm sure you know what i mean) until tomorrow

[trixsimtb]

Hi Rich, I now have a photo but can't see a way of attaching it to this discussion?

[lutonlagerlout]

i had my patio cleaned in February,
its an off shade of green again, although it is north west facing and surrounded by tall trees

its just maintenance

LLL

[dig dug dan]

if they are saxon buff (marshalls) then i would have laid the but jointed.
Just a thought. no reason why you can't point them in though

[Rich H]

How to upload photos

[trixsimtb]

heres the link for the phhotos
http://www.flickr.com/photos/30064917@N08/2807449743/

http://www.flickr.com/photos/30064917@N08/2807449745/

http://www.flickr.com/photos/30064917@N08/2807449751/

Let me know what you think

[Rich H]

Nothing to worry about there, but I'd get it cleaned up to stop it from getting worse.

http://www.pavingexpert.com/maintain_02.htm#aml

[trixsimtb]

Thanks for you input, its great to know it should look good again next year, I'll get it cleaned up as per the instructions and fingers x'd for a long hot summer next year.