Marmox Thermoblock - sealant needed?

[Dunc]

Specifying a course of marmox thermoblock to break a thermal bridge in my foundation blockwork. Is there any value in using the sealant?

Tech data from Marmox says "Marmox sealant should be used to seal the ends of the Thermoblocks together to prevent moisture creeping up between blocks and to ensure air tightness of the building."

I don't need the air tighntess as that's dealt with at the timber frame/slab junction and the blocks are below this.

It's outside the DPM so I don't need the blocks to be sealed to keep water out of the rest of the structure, just wondering if there's concern with water ending up bewen the blocks?

[Nickfromwales]

1 hour ago, Dunc said:

Specifying a course of marmox thermoblock to break a thermal bridge in my foundation blockwork. Is there any value in using the sealant?

Tech data from Marmox says "Marmox sealant should be used to seal the ends of the Thermoblocks together to prevent moisture creeping up between blocks and to ensure air tightness of the building."

I don't need the air tightness as that's dealt with at the timber frame/slab junction and the blocks are below this.

It's outside the DPM so I don't need the blocks to be sealed to keep water out of the rest of the structure, just wondering if there's concern with water ending up between the blocks?

It's down to the manufacturers installation instructions (MI's), recommendations and guidelines, eg is the moisture thing mentioned in respect of their longevity, and therefore may affect the warranty of the product if you 'stray' away from the MI's?

 

What if the water gets in and then freezes etc?

[Dunc]

Just to feed back on this in case someone else has this question:

Marmox tech support (yes, I should have phoned them first!) confirmed that the sealant is only recommended where airtighess or DPM function is needed; there is no problem using the blocks without the sealant.