Rendering foundation blockwork below SIPS sole plate

[Longjock]

Hi guys,

 

I've got to crack on with making the decision on what to use for the area of blockwork below the sole plate. The drawings show to use EPS and Stolit K up to the dpc level but after speaking further to the architect, he has suggested in carrying the eps up over the sole plate to aid with the thermal bridging in that area.

 

The external walls will be vertical timber clad down to this level so the top surface will be hidden and the lower edge of the rendered area will have shingle up to it in the 'drip area'.

 

My dilemma is that everything I look at online about rendering on EPS is based on full walls, rather than this area. Do I have to follow this process (starter beads/adhesive AND mechanical fixing etc.) or is there a more cost effective/simpler way of getting the job done. 

 

All the local 'trades' round here, only ever talk about sand and cement but I know this won't work with EPS.

 

Any help given will be appreciated. 

Edited August 1, 2020 by Longjock

[Temp]

I cant really help answer your question but I know that not all renders are approved by the manufacture for use below DPC so I would contact them to ask about that.

[Temp]

I guess you may have looked here already but looks like they have their own EPS system...

 

http://www.sto.co.uk/en/products/external-wall-insulation/downloads.html

 

 

[Longjock]

Yep, been looking there. 

 

I’m giving them a call on Monday for advice. 

 

The only other info i’ve picked up is using mosaic render but that stuff is so expensive. 

 

 

[nod]

If your asking can you render under the dpc onto the eps 

The answer is yes I am often asked to do this I normally say put stones or shingle against the render Or if you decide to flag 

run dpc against the render to flag to leaving about 10 mil sticking up 

 

[Russell griffiths]

What product would you recommend @nod to go on to eps, but under dpc down to the ground. 

[nod]

I always use HP 12 

Its a bit more Water resistant 

[Longjock]

Cheers @nod , the shingle up to the render is the plan.

 

I’ve just looked at the HP12 and it says it’s good for fixing the eps to the substrate, but are you saying to then use this as the following basecoats (with mesh)? Do you then put a top coat on or just paint? 

 

I’ve never had to look at any rendering before, hence the understanding of this process.

Edited August 1, 2020 by Longjock

[nod]

1 hour ago, Longjock said:

Cheers @nod , the shingle up to the render is the plan.

 

I’ve just looked at the HP12 and it says it’s good for fixing the eps to the substrate, but are you saying to then use this as the following basecoats (with mesh)? Do you then put a top coat on or just paint? 

 

I’ve never had to look at any rendering before, hence the understanding of this process.

Yes no problem 

Yes you would apply the HP12  directly to the EPS About 3 mil thick Then press the fibre mesh on to the base coat Run a trowel I’ve it  then give it a light skim coat of HP12  ( Backing coat) 

Then after about an hour give it a ver light scratch 

You can apply a 10-15 top coat  any time after 24 hours 

 

  Hope this helps 

 

[Longjock]

Hi guys, finally getting round to starting on this. I’ve primed the blockwork ready to stick the eps on to, but I’m not sure about the dpc sticking out from under my sole plate. Do I tuck this down behind the eps board or do I trim it off or what? 

[Lynsey]

Hi. We’re building a sips house and are wondering what to do here too. What did you end up doing? Thanks Lynsey