Visible gaps between breeze blocks in an external wall.

[AskingQ]

Our builders have left quite a lot of thin gaps between the breeze block in the external walls of a house we are having built.
Clearly they laid some blocks the wrong way round so they don't kiss-closed properly.
They say this doesn't matter and once the wall are covered inside and outside with plaster/coating we won't notice.

Should we believe them?
Are such gaps likely to lead to cracks in the plaster in the passage of years?
Wouldn't it be better to fill these gaps with a setting liquid cement mix now?

Any advice would be great.

 

[Deluks]

Probably not uncommon on the continent where weather may be less severe. Breeze blocks don't have a 'wrong way round'
Are these are the hollow red clay blocks?

 

[^woody^]

Mortar joints should be completely full - to properly bond the blocks to spread loads, to prevent water seepage into the voids (and frost attack here in the UK), and to prevent air leakage and increase thermal insulation properties (again UK/cold climates specific)

Either way the builders have not built the wall properly, and any gaps should be filled

 

[Nige F]

Hey, Doana diss da builder - he gotta mates

 

[AskingQ]

Mortar joints should be completely full - to properly bond the blocks to spread loads, to prevent water seepage into the voids (and frost attack here in the UK), and to prevent air leakage and increase thermal insulation properties (again UK/cold climates specific)

Either way the builders have not built the wall properly, and any gaps should be filled

Many thanks woody

What would be the right way to fill the gaps?
It's difficult to think how to get mortar into them now the wall's built.
Someone suggested polyurethane foam.