ᐅ Gap in the Poroton T9 block

Hello everyone,
a brief introduction about myself...

I am a nurse and had absolutely no experience with building.

Currently, I am building a single-family house using Wieneberger Poroton T9 blocks. I do not have a general contractor by my side, and although my architect is knowledgeable about planning, he has less experience with the actual construction. So far, everything has gone very well, but since I am not a professional, quite a few questions have come up, which I have fortunately been able to handle so far. However, I am now hearing different opinions...

Anyone familiar with the T9 block, which is 36.5 cm (14.4 inches) thick, knows that cutting it often causes corners to break off because the inside is quite fragile. Now I have some areas in the masonry with gaps of about 3-4 cm (1.2-1.6 inches). How should I fill these gaps? My architect suggests filling them with thin-bed mortar because they contain "Styrofoam" and also provide insulation (which I find hard to believe).

I was thinking of filling the gaps on the inside with foam and then applying mortar on both the inside and outside. If that is correct, should I apply the insulating foam as far to the outside or the inside as possible? And which type of foam would be best to use? Are there better alternatives?

The roof is already installed, and the windows are coming next week. Now I want to fully close up the house...

Thank you very much for your upcoming help.

Could you upload a few photos? That would be very helpful.

Respect! I would listen to the architect. In the past, when I was still building in a more hands-on way, I would probably have filled the 3 to 4 cm (1 to 1.5 inch) wide gaps with a suitable brick fragment. But it’s best to leave that decision to the architect (especially if no bricklayer is involved).

Photos would still be very interesting, of course!

Expanding foam inside the wall is not ideal; it should be applied either completely on the exterior or completely on the interior. If used inside at all, possibly use well foam.

The problem is that the moisture absorption and release of regular expanding foam (e.g., through capillary action) is different from that of the masonry.

Depending on your wall construction, the dew point may be close to the foam, which can lead to condensation issues.

Thin-bed mortar is too fluid and will just run out immediately.

Simply mix mortar (mortar powder) in small amounts and seal the openings from both outside and inside. If the openings are too large, incorporate leftover pieces of other bricks. Air inside the wall is not a problem; on the contrary, air is a poor conductor of heat.

There is special insulation mortar available. Wouldn't that be the best option? That's how I would do it, anyway.

The file is unfortunately too large to upload as a photo... But thanks in advance for the answers.