Help with blocked off cavity

[akist]

I blocked off a cavity around a door opening using 100mm blocks in between existing 100mm blocks forming the cavity wall.

There are many vertical gaps between the blocks on the sides, some very small, some larger, and a significant gap over and above where I placed a concrete lintel on its thin edge (65mm) as I could not fit it on its flat side.

I would like to close all those gaps, and would like help and suggestions. Use a mortar gun maybe? I have read they clog up really easily. Use 5 star grout or just sand and cement? And how do I close the gaps on the lintel above?

 

[thomp1983]

If your just closing gaps use expanding foam in a gun so you can control it

 

[noseall]

I blocked off a cavity around a door opening using 100mm blocks in between existing 100mm blocks forming the cavity wall.

There are many vertical gaps between the blocks on the sides, some very small, some larger, and a significant gap over and above where I placed a concrete lintel on its thin edge (65mm) as I could not fit it on its flat side.

I would like to close all those gaps, and would like help and suggestions. Use a mortar gun maybe? I have read they clog up really easily. Use 5 star grout or just sand and cement? And how do I close the gaps on the lintel above?

As said - Ex-foam is brilliant at filling slender gaps. Get a spray bottle and damp any of the holes first, especially those that have gravity working against them. If you have over-head gaps to fill, do these whilst the foam can is at its fullest.

 

[akist]

Thanks guys. I have used expanding foam extensively in other situations, but in this case I wanted something more structural to close the gaps.

I recently bought a mortar gun (https://www.amazon.co.uk/gp/product/B01AX08IWS), If I mix 1:2 or 1:3 muck and make it runny and try to see how it goes. Not sure how to handle the overhead gap.