Rendering polystyrene

[Highland build]

Hi I wanted to put this in the rendering plastering trades section but couldn't click on that topic title for some reason.

Has anyone rendered onto external polystyrene insulation?

Its actually the base of my founds an EPS insulated raft.

The two products i'm looking at are

Aquabase EWI 226 a silicone render system with a fiberglass mesh

or

a cement slurry aquamat elastic with either 10cm polyestewr fleece or fiberglass mesh

 

Anyone done this before and got any advice on either product or covered their EPS RAFT base in anything else that worked well?

 

Cheers

 

[Gone West]

  On 25/08/2022 at 09:47, Highland build said:

Anyone done this before and got any advice on either product or covered their EPS RAFT base in anything else that worked well?

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I stuck brick slips on mine, and five years later they were still there when I sold it.

[Highland build]

Have you got any photos @Gone West and what are brick slips?

[MikeGrahamT21]

ewistore.co.uk

 

P.S. thanks for the reminder that i'd actually done this, forgot to put it up

 

 

Edited August 25, 2022 by MikeGrahamT21

[Gone West]

  On 25/08/2022 at 12:20, Highland build said:

Have you got any photos @Gone West and what are brick slips?

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Brick slips are slices of brick 10mm to 15mm thick which can be stuck to various substrates to give the effect of a solid brick wall. It certainly works as everyone thought our brick slips were whole bricks.

 

https://www.wbs-ltd.co.uk/systems-solutions/system-finishes/15mm-brick-slips/

 

On the area under the porch glazing I stuck the brick slips directly to the EPS using gel PU glue. On the area under the front door you can see the EPS which was covered by the ramp up to the door. On the rest of the brick plinth the brick slips were attached using the Wetherby system on to BluClad board.

 

 

[Nick Laslett]

  On 25/08/2022 at 09:47, Highland build said:

Hi I wanted to put this in the rendering plastering trades section but couldn't click on that topic title for some reason.

Has anyone rendered onto external polystyrene insulation?

Its actually the base of my founds an EPS insulated raft.

The two products i'm looking at are

Aquabase EWI 226 a silicone render system with a fiberglass mesh

or

a cement slurry aquamat elastic with either 10cm polyestewr fleece or fiberglass mesh

 

Anyone done this before and got any advice on either product or covered their EPS RAFT base in anything else that worked well?

 

Cheers

 

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We had our Kore Insulated Foundation perimeter rendered with EWI-050 Mosaic, this is their below DPC product. This was about two months ago.
 

https://ewistore.co.uk/shop/external-wall-insulation/mosaic-render-ewi-050-25kg/

 

 

[Highland build]

hi @Nick Laslett So did you do the basecoat and the mesh and then the mosaic render over the top as a second coat?

@Gone Westthose brick slips look amazing was yours isoquick base?

[Nick Laslett]

  On 03/09/2022 at 19:11, Highland build said:

hi @Nick Laslett So did you do the basecoat and the mesh and then the mosaic render over the top as a second coat?

@Gone Westthose brick slips look amazing was yours isoquick base?

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Yes. Base coat, mesh, acrylic primer then mosaic.

 

EWI-225 Premium Basecoat

Orange Fibreglass Mesh

EWI-330 Acrylic Primer

EWI-050 Mosaic Render

Here is the EWIPro technical drawing for the below ground build up. 
 

https://ewipro.com/wp-content/uploads/2022/02/4-Base-profile-with-an-insulated-plinth-and-insulation-system-installed-below-ground-level-1.pdf

 

They spec EWI-226 Aquabase in this drawing. 
 

Our renderers specified the EWI-225 Premium basecoat for the walls and the below DPC foundation surround. I never questioned if we needed something different for the foundation. Looking at the spec sheets, EWI-225 is also frost resistant and water resistant. Not sure if the Aquabase is cheaper?

 

Edited September 3, 2022 by Nick Laslett

[Nick Laslett]

I think EWI-226 Aquabase is preferred for XPS and EWI-225 Premium is preferred for EPS. The Aquabase is more expensive. 

I also found the NSAI certificate, which I find a better read than the BBA equivalent. 
 

https://www.nsai.ie/images/uploads/certification-agrement/21_0428_EWI_Pro_External_Insulation_Systems.pdf

 

*Edit timeout, or I would have added this to the earlier post. 

Edited September 3, 2022 by Nick Laslett

[Gone West]

  On 03/09/2022 at 19:11, Highland build said:

@Gone Westthose brick slips look amazing was yours isoquick base?

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Yes, it was the first Isoquick installation in England in 2010.

[Highland build]

@Nick Laslett this is amazingly helpful thank you so much had a gur round last night to look at it and i think were gonna go with the render.

Have you got any photos?

[Nick Laslett]

  On 06/09/2022 at 08:42, Highland build said:

@Nick Laslett this is amazingly helpful thank you so much had a gur round last night to look at it and i think were gonna go with the render.

Have you got any photos?

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First photo is garage, this shows EW-330 acrylic primer on the left and the Mosaic on the right. 

 

 

[Nick Laslett]

Second photo, corner of house with wall render and mosaic. 
 

 

[Nick Laslett]

Another photo from much earlier in the build, showing the ICF blocks on the EPS foundation. 

[Highland build]

@Nick Laslett

Brilliant I've got ten bags of the aquabase 226 and the mesh and corner beads delivered so I'm gonna just go for a coat of that and see what it looks like if the colours too dark for me apparently you can paint it with silicone based paint.

I'll get some before and after pics and see for the group.

Cheers

Maddie

 

[Russell griffiths]

  On 13/09/2022 at 10:38, Highland build said:

@Nick Laslett

Brilliant I've got ten bags of the aquabase 226 and the mesh and corner beads delivered so I'm gonna just go for a coat of that and see what it looks like if the colours too dark for me apparently you can paint it with silicone based paint.

I'll get some before and after pics and see for the group.

Cheers

Maddie

 

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It won’t be dark, it dries a very light grey colour. 

You really need the mosaic on top as the base is not very attractive, unless you can get a sponge finish on it.