What adhesive for loose stone cladding to block wall?

[Hemmas]

I’m looking to apply dry stack loose stone (20-40mm thick) cladding to a new core filled block work wall. The rear of the wall has been water proofed before backfill.

if I’m stone cladding the front face of the wall:

*Do I need to water proof

the wall before stone cladding?

*Do I need to render the wall before applying the Adhesive? If so I assume it would only be a single scratch coat?

*Can I avoid rendering by using a primer instead?

*Is the Davco SMP EVO the best adhesive for loose stone cladding?

*Is there a recommended sealer for once the stone cladding is complete?

 

[EricL]

Hello @Hemmas 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about what adhesive loose for loose stone.

Please allow us to double check with our supplier in regards to your intent to use the adhesive to anchor stone to your masonry wall. Although the website does mention stone, I think it refers more to stone tiles. As soon as we have more information, we'll get back to you.

In regards to your other questions, I don't believe there is a need to render the surface of the masonry wall. I propose looking at the Crommelin 1L Natural Finish Penetrating Sealer And Water Repellent to seal the stone surface.

Thank you for your patience.

Eric

[JacobZ]

Hi @Hemmas,

I'm just confirming that our suppliers have confirmed Davco SMP Evo Tile Adhesive is a suitable adhesive for this purpose.

Jacob

[Hemmas]

Thanks Jacob,

Would you recommend a water proofing application, primer or scratch coat render for this job?

[JacobZ]

Hi @Hemmas,

I'm just in communication with the Sika team, who are sending me a specification for stacked stone cladding.

So, I can give you the most relevant information possible, can you advise what kind of stone you were using? The moisture sensitivity of the stone can sometimes be a factor.

They have recommended using Sikalastic 1-K as a negative side waterproofing membrane, which should be standard regardless of the type of stone used.

I just need to confirm whether a specific primer would be needed, and that the SMP Evo is the best choice for your specific stone.

Jacob

[Hemmas]

Hi Jacob,

thanks once again for your help.

I'm looking to use the below stacked stone

https://nuway.com.au/free-form-clouds-random-cladding-20-40mm

could you confirm the negative side waterproofing is applied before the adhesive (including primer if required) and that no scratch coat render or similar is needed?

[JacobZ]

Hi @Hemmas,

The specification I received from the Sika technical team says that the wall should be rendered according to the following recommendation.

"A splash coat must initially be applied to the face, which consists of:

1 Part Lankolatex 751, 1 part water and 2 parts neat cement.

The splash coat should be applied with a brush or broom and must not exceed 2mm in thickness. Whilst the splash coat is still moist and tacky, the render must be laid. 

It is required that 1 part Lanko 751, 3 parts water be used as an added mixture in the render mix in place of water. This enhances adhesion, flexibility, tensile strength, impact/water resistance in the rendered wall. The use of plasticisers in the render mix is not permitted.
 

The render mixture should be:

1 part cement, 3 - 4 parts clean, washed sand

Renders shall be allowed to dry for 5-7 days prior to applications of waterproofing membrane or stone adhesives."

Once the render has dried for 5-7 days, apply a minimum of 2 coats of Sikalastic Sikalastic 1K, allowing it to fully dry between coats.

You should then apply your Davco SMP Evo over the waterproofing membrane and install your stacked stones.

I have forwarded a copy of this specification to your email address for your perusal.

If you had further questions, please don't hesitate to reach out. You could also contact Sika's technical team on 1300 223 348 for further guidance.

Jacob

[JacobZ]

Hi @Hemmas,

Just to add a point that I missed, Sika's technical team recommended using Davelastic Additive mixed 50/50 with clean water to mix your SMP Evo.

This adds flexibility, strength and water resistance to cement-based products such as SMP Evo.

Jacob