Render options

[Alexphd1]

We are doing a Icf house and have started to look at renders. We like the roughcast finish. We are amongst a lot of trees. What's the options traditional, acrylic.  Anything to avoid?  

[ProDave]

We are using the Baumit.com render system, marketed in the UK under the "lime green" name (which I think is a very confusing name as peiople expect that to describe the colour)

I know from talking to the plasterer today that it can be applied to EPS so should be okay for an ICF build.

Here's some pictures of it on my blog

http://ardross.altervista.org/Wilowburn/let-the-rendering-commence/

 

[Alexphd1]

I presume that's a lime based render?

[reddal]

Hi,

I think we used the same stuff for our house. The exact type was K39 I remember if that helps?

I wasn't very involved in that part of the build - but what I remember is :

• we used a LOT more of the stuff than the original estimate (more than three times as much if I remember correctly)
• it was a bit fiddly to apply. It was a learning experience for the guys doing it - took a while
• there were all kinds of constraints on the temperature / humidity and how to protect it whilst drying
• There was some complexity about the build up of metal mesh / cavities etc that were needed (I can try to look up the details of that if its useful)

However - its been up a few years now and its worked pretty well - with very little maintenance. The finish does look nicer (to my eyes at least) than some of the alternatives.

- reddal

[ProDave]

Yes it's a lime based render system.

No problems at all so far. We have used LESS materials than estimated so far.

Base coat is called MC55W and is mixed from a powder.  As it starts to go off, a fibreglass mesh from a roll is pushed into the wet render.

Next day a primer called DG27 is painted on, it's a bit like PVA.

Then the top coat called Silikon top is applied, that comes pre mixed in tubs. You can get different colours and different textures.

Temperature has to be above 5 degrees for 3 days after application. No problem at this time of year, even up here.

[Alexphd1]

Thank you for your reply.  I will have a look more into this product. 

[Ferdinand]

8 hours ago, Alexphd1 said:

We are doing a Icf house and have started to look at renders. We like the roughcast finish. We are amongst a lot of trees. What's the options traditional, acrylic.  Anything to avoid?  

In my view avoid white render around trees like the plague.

Or you may:

1 - Spend your lives cleaning it.

2 - Become "the people with the dirty house".

A house near here have managed to remove / pollard 10 large TPO Trees around their house after a decade of trying (mainly removed as a risk to the public), and it is now clear how encrusted their drainpipes and windowframes have become; many currently remark that it looks uncared for. 

This one will be cleaned OK, but I would suggest a darker shade, bearing in mind your type of trees and what they will drop on your house.

Others may disagree or have ideas of dirt-resistant renders.

Ferdinand

 

Edited June 15, 2016 by Ferdinand

[JamieM]

Do you know if there is much of a price difference in the Baumit.com render system and the likes of weber?

thanks

[ProDave]

I didn't compare. I went for the recommendation of what was best and proven to work with the wood fibre cladding. For my entire house the render materials, that's all the render and all the corner beads, bottom beads, window beads etc has cost £3662 excluding VAT (I have paid the VAT and will reclaim it at the end of the build) That was sourced through a local low energy house builder so some big bulk discounting there. I looked at buying the materials myself and the best price I could find was £5K

I don't like to say bad things about other render systems but my plasterer has used another well known render system and says it has big problems with cracking. He has never had that problem with the Baumit stuff.

[JamieM]

cheers. Yes, I've heard issues with cracking with other renders.  I'm still at the 'type of render' decision stage but I'll have to look into it to see if it works with block and to check if its available in NI.

thanks again

 

 

[Stones]

As you know, we are building with ICF as well.  We've decided to go with what the builder specs on all his houses, a spray on self cleaning silicone based render.  I'll try and find out the manufacturer / product name.  Best described as a fairly smooth finish with a bit of grit and texture (1 - 2 mm sized) in it.  

The other ICF contractor up here finishes houses with dry dash, and by chance I saw the render going on.  As Dave describes, base coat goes on an a fibre glass mesh pressed into it, followed by primer then a top coat which is dry dashed. The chap doing the render said that although expensive (compared to sand / cement render) it was far more flexible and therefore robust in the long term.

I think you can achieve any finish you want, but I think ultimately it will be a render system you need rather than sand / cement based.

[Trw144]

Does anyone have any £/m2 prices for render systems such as Weber, Krend, Baumit?

 

I used Krend on the last place and have to say I had no issues. My render guy has quoted me for aquapanel with Krend and I thought it was a lot at around £70/m2 (all materials including cement board and labour)?

[ProDave]

The Baumit render system worked out about £20 per square metre for the render, and about £25 per square meter for the labour to apply it.  I used 100mm thick wood fibre board that is a lot more expensive than cement board, but the whole point being it's another 100mm of insulation on the outside of the building.
 

[Trw144]

Ok, so £70 per m2 is probably about right by the time the render board is added into the mix. Small world but I have a contact in Austria who recently joined Baumit as a sales director - time for an email I think.

 

Presumably it can be applied to render board as well as wood fibre board?