Rendering concrete blockwork

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neb

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#275868 14-Sep-2020 14:55

As part of the Casa de Cowboy rebuild, we're going to render the basement blockwork both for weatherproofing and to get away from that concrete-block-basement look and feel. However there's a ton of different finishes ranging from fairly standard mortar (Resene) to fancy composite/polymer/acrylic-based systems that claim to provide better flexibilty and weathertightness (Sto, Rockcote, Rockbond), and in the spirit of Motörhead everyone's system is better than everyone else's. It's in a vaguely coastal area so will get wind-blown dirt and a minor amount of salt spray, we're going for a smooth finish to provide less for the dirt to stick to and ease cleaning.

Does anyone have any recommendations for/against any of these?

neb

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#2563814 14-Sep-2020 15:12

Following up, from some poking around it looks like Resene is rebranded Rockcote, they just pass you on to a Rockcote contractor. This one also looks like the most labour-intensive option, multiple layers of coating and paint, but also the most rigorous, with precise details, flashing, and so on as opposed to some others' "mix it up and slap it on". So I'm leaning towards Rockcote at the moment...

MikeAqua

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#2563823 14-Sep-2020 15:33

I suggest you compare the warranty requirements for each system.

We had the Resene system on our last house and it required a 7 yearly repaint to maintain warranty.

The paint didn't even look slightly degraded at that point.

Mike

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#2563841 14-Sep-2020 16:15

neb: Following up, from some poking around it looks like Resene is rebranded Rockcote, they just pass you on to a Rockcote contractor

FYI, Rockcote = Resene in NZ.

Rockcote did start in Australia. But since 2002 Rockcote in NZ has been owned by Resene, now as Rockcote Resene Limited and previously as Rockcote Architectural Coatings (N.Z.) Limited. AFAIK, Resene's still manufactures it in NZ.

Edited to add 2002 news release link: https://www.resene.co.nz/comn/whtsnew/rockcote.htm
(Finally, a use for some arcane local knowledge. 😀 Not that this is of any real interest. 🙃)

neb

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#2563997 14-Sep-2020 18:32

MikeAqua:
I suggest you compare the warranty requirements for each system.

We had the Resene system on our last house and it required a 7 yearly repaint to maintain warranty.

The paint didn't even look slightly degraded at that point.

I haven't been able to find any reference to that, just a 15 year materials warranty and a 5 year workmanship warranty. The only thing I could find on repainting was:

Repainting the exterior should be undertaken by a professional painter every 7 – 10 years to ensure the integrity of the entire system is kept good.

which is Resene's standard advice for exterior painted surfaces.

MikeAqua

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#2564203 15-Sep-2020 09:35

neb: I haven't been able to find any reference to that, just a 15 year materials warranty and a 5 year workmanship warranty. The only thing I could find on repainting was:
Repainting the exterior should be undertaken by a professional painter every 7 – 10 years to ensure the integrity of the entire system is kept good.
which is Resene's standard advice for exterior painted surfaces.

It was in the warranty documentation that the previous owners left for us and Resen actually sent a reminder letter addressed "to the householder" after 7 years. I'm sure it specified recoat in 7 years, but it's possible it was inspect and recoat if required.

However, if you get a painter to inspect, what are the chances they are going to say it doesn't need a recoat?

Mike

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#2564213 15-Sep-2020 09:51

My BiL repaints about every 7-8 years. Only takes a couple of days with a good clean being the only prep needed. If you push it out it only takes something to distract you and the finish is shot needing lots of work. I can remember when 10 year paint life was a big deal "40 Seasons" etc. Before then quite a few used to do 1 side a year on a 4-5yr cycle.

MikeAqua

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#2564250 15-Sep-2020 10:39

Bung: My BiL repaints about every 7-8 years. Only takes a couple of days with a good clean being the only prep needed.

With the Resene system, DIY doesn't cut it. Has to be an approved/qualified painter.

Mike

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Bung

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#2564343 15-Sep-2020 13:38

It gets worse. I see that unless you kept tight control on your designer you could have areas needing frequent inspection and 2-5 year painting cycle.

neb

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#2566245 16-Sep-2020 21:19

Bung: It gets worse. I see that unless you kept tight control on your designer you could have areas needing frequent inspection and 2-5 year painting cycle.

Could be a quality-control thing. If you look at their docs they have specific requirements for use for flashing, the way it's applied, etc, while others don't go much beyond "mix it up and slap it on". That's one of the things that drew me to it, that there's actually a rigorous procedure for working with it. So the warranty thing you mention could be because people have ignored the installation instructions and then complained when it went wrong.

neb

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#2700579 2-May-2021 00:37

We're now at the stage where we're ready to get this done but the guy we had lined up is booked solid for ages, can anyone recommend someone in Auckland to do this? The Resene/Rockcote site lists a huge number of companies, any kind of recco would be useful.

Edited to add: The fact that Resene's list mostly seem to have copied each other's cover letters doesn't inspire too much confidence, which is why I'm looking for recommendations: Sample 1 Sample 2 Sample 3.