Parex or Lime Render?

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spunky said:
yes cpi of course you can mix sand with cement and lime
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Ok, but ALL plasterers I know and have used in the past site mix their S/c render. I've never been asked to supply cpi or any other similar product. It might be the go for larger sites where time is premium, that's not necessary in this case.

I've just come back from a builders merchants where there are as many NHL render products (with mix specifications) as there are prebagged, Why? If everyone used prebagged why is NHL instructed specifically for rendering available?
 
alot of monocouch renders contain silicon seriously i doubt nhl contains it i reckon if it did it wouldnt breathe aswell for a start
nhl is used for refurbishment on older properties where the walls are single skin and need to breath or over old lathe work
monorex is used in modern builds with certain blocks or over tricky backgrounds you use a suitable primer/basecoat
when youve finished with monorex you leave it with nhl you need to nurture it keeping it wet etc do you not understand there two entirely different products?
 
spunky said:
alot of monocouch renders contain silicon seriously i doubt nhl contains it i reckon if it did it wouldnt breathe aswell for a start
nhl is used for refurbishment on older properties where the walls are single skin and need to breath or over old lathe work
monorex is used in modern builds with certain blocks or over tricky backgrounds you use a suitable primer/basecoat
when youve finished with monorex you leave it with nhl you need to nurture it keeping it wet etc do you not understand there two entirely different products?
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No I don't understand the difference. The CoSH sheet for Monorex doesn't state it contains much other than NHL3.5 and sand aggregates. It mentions other minerals but nothing specific, and as far as I can see, not in any significant quanities otherwise it would have to be listed for CoSH.

I've used a single skin walling product called Porotherm (Wienerberger), It's what I would call a lightweight terracotta block made porus by firing it with impurities that flash-off leaving micro-pores. It needs to breath. I've been quoted Monorex as a render finish. How breathable is Monorex as it contains silicon?
 
spunky said:
not sure bought i heard on here all parex renders are breathable
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Here spunky, I've been sat here going over some CAD drawings for a planning application and enjoying the crack. I'm pretty sure it's worth going with the bagged products (Monorex) just for the peace-of-mind and the finish. Hope I can find good trade to do it justice.

However, I'm still not convinced that they contain a great deal more other than NHL and washed sands. It would be nice to have someone from Parex (or similar) to comment.
 
spunky said:
alot of monocouch renders contain silicon seriously i doubt nhl contains it i reckon if it did it wouldnt breathe aswell for a start
nhl is used for refurbishment on older properties where the walls are single skin and need to breath or over old lathe work
monorex is used in modern builds with certain blocks or over tricky backgrounds you use a suitable primer/basecoat
when youve finished with monorex you leave it with nhl you need to nurture it keeping it wet etc do you not understand there two entirely different products?
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What do you mean by 'leave it with nhl'? Just so I know.
 
I'm not quite ready for render yet anyway, just doing the homework. I should be ready for about September/October this year.

I've been talking to some others that have used the nhl/sand hand mix, to what success, I'm not sure. I think you've got to really know what you're doing with it, especially in this case as the Porotherm block sucks like nothing I've seen before. The majority of properties that I've seen rendered here are done in Monorex or similar and are machine applied.
 
id let them know at parex there high suction are they smooth clay? you might need a base coat if you do you want to make sure that breathes too
 
spunky said:
id let them know at parex there high suction are they smooth clay? you might need a base coat if you do you want to make sure that breathes too
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Good call, I'll email them. They must have come across Porotherm before as it's very common for this type of build. I've been in touch with Wienerberger but they won't be specific about product naming, just types of render.
 
Plasteringrooky said:
No, neither are you expected to have aggregrates, limestone and gypsum quarries, but you still use sand/cement renders mixed on site. Do you buy sand/cement prebagged?
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CPI Euromix supply 6-1-1 mix premixed, we use it all the time as you get quality control in the mixing rather than having some brain dead labourer messing up the mixes because his mate texted him. if you need the number of there rep just ask mate and i will pm it over to you.
 
simplybesty said:
CPI Euromix supply 6-1-1 mix premixed, we use it all the time as you get quality control in the mixing rather than having some brain dead labourer messing up the mixes because his mate texted him. if you need the number of there rep just ask mate and i will pm it over to you.
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Hi besty,

Thanks for the offer, but I rarely get involved with the plastering/rendering side of things. When I do I just usally let the guys get on with it, that's what they're good at and I trust them. Unfortunately my usual guys aren't availavle for this project due to location. I don't think they would have ever used the likes of Monorex anyway.

This is a personal project and straight from the pocket, so I'm just making sure that my final choice is one I'm happy with having done some research. I'm learning a little on the way too, which can't be a bad thing.

I must say aswell, I've used a few forums in the past and this has to been one of the best. Friendly. I imagine you can have your patiencs stretched at times on here.
 
Allow me to introduce myself I am a lime for over 15 years working in Ireland. Before that I was a cement/gypsum plasterer.

The usual external lime plasters are mixed on site. For example St Astair, Roundtower and Autobein NHLs are mixed with sand on site. Some of the pre bagged plasters are not breathable and if you do not need breathability it is cheaper to use sand and cement.
 
spunky said:
Can you scrape NHL to leave a pitted finish?
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If I was to render it myself in nhl I would spray apply and taloshe (wooden float) the tops back, or talosh and sponge a smooth finish. The reason for the pitted finish with Monorex is that it works out cheaper and would still be a nice contrast against the sponged raised bands around the windows, if done properly.
 
brendankelly said:
Allow me to introduce myself I am a lime for over 15 years working in Ireland. Before that I was a cement/gypsum plasterer.

The usual external lime plasters are mixed on site. For example St Astair, Roundtower and Autobein NHLs are mixed with sand on site. Some of the pre bagged plasters are not breathable and if you do not need breathability it is cheaper to use sand and cement.
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Hi Brendan,

Thanks for the reply. Are the Brendan Kelly on Youtube giving lime rendering leasons?

Have you used both lime renders by blending lime (NHL3.5 or 5) and sand on site and used prebagged products like Monorex to give a comparison?
 
Plasteringrooky said:
Hi Brendan,

Thanks for the reply. Are the Brendan Kelly on Youtube giving lime rendering leasons?

Have you used both lime renders by blending lime (NHL3.5 or 5) and sand on site and used prebagged products like Monorex to give a comparison?
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That is me on u tube. I was working with a company called Hempire and that is the promotional video. Hempire is a premixed hemp and lime render that is good but only if used properly. The guy that owns the company started selling it as a DIY product and idiots that did not know a float from a trowel did a high profile job with it and the rest is history. We now always mix our own render on site.
Premixed renders will not last more than a few years. Here I see monocuse renders failing after about 6 years (this is probably due to bad workmanship) and also monocuse is not breathable and it contains a lot more than NHL and sand. There are a lot of systems been tried out here at present i.e. Parex, Sto, Guetex etc but as far as I can see none of them are breathable. Parex is been used a lot over polystyrene as an insulation here but the polystyrene reacts with the temperature and therefore you will have cracks.
We have looked at nearly all renders and tried many but my first choice would be St Astair for every place and Gutex or lime putty for skimming.
 
brendankelly said:
That is me on u tube. I was working with a company called Hempire and that is the promotional video. Hempire is a premixed hemp and lime render that is good but only if used properly. The guy that owns the company started selling it as a DIY product and idiots that did not know a float from a trowel did a high profile job with it and the rest is history. We now always mix our own render on site.
Premixed renders will not last more than a few years. Here I see monocuse renders failing after about 6 years (this is probably due to bad workmanship) and also monocuse is not breathable and it contains a lot more than NHL and sand. There are a lot of systems been tried out here at present i.e. Parex, Sto, Guetex etc but as far as I can see none of them are breathable. Parex is been used a lot over polystyrene as an insulation here but the polystyrene reacts with the temperature and therefore you will have cracks.
We have looked at nearly all renders and tried many but my first choice would be St Astair for every place and Gutex or lime putty for skimming.
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Thanks Brendan, that all kind-of makes sense. I'm not completely convinced by the prebagged renders being breathable enough for the Porotherm block background. These blocks are very porus, which gives them their insulating quality, howerver they are used here a lot and the monocouche seems to be the norm. I'm on pretty good terms with the manager of a large builders merchants who has a long history when dealing with these types of blocks and render finishes. I'll take a trip to see him, see what he saids. That'll cost me a lunch I suppose!

Many thanks for the well informed (experienced) advice.
 
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