Crack in concrete floor of first floor flat. How bad is this?

[sandblast]

Hi all

I’m in the process of redecorating my first floor flat in a block of two built in 1980.

Lifting the carpet revealed these two cracks by the kitchen doorway area. They were about 4cm apart. I removed some of the loose concrete. When I’ve removed the other loose piece, the cavity will measure around 30cm x 4cm x 4cm.

I have purchased some Concrete Repair Mortar and am ready to fill it, but before I do that, I just thought it might be an idea to know if this is more serious than it looks, and wondered if maybe I need some kind of professional opinion.

I don’t know how this happened, but I’m assuming it happened gradually. The building vibrates a little bit every time a heavy vehicle goes by on the main road, which has always bothered me. I don’t know if that’s related.

Any help or advice is appreciated!

 

[dazlight]

Ardex A45 would be ideal

 

[dazlight]

This would do though

Bostik General Purpose Mortar Grey 5kg - Screwfix

Order online at Screwfix.com. General purpose mortar. Ideal for bricklaying, rendering, pointing and masonry repairs. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

 

[sandblast]

Ardex is better sure, but it’s quite expensive. The mortar you linked there is near identical to the NN version I bought, albeit a bit more expensive...

I really just posted to see if anyone thought the crack presented a structural problem. But then, it is the flooring forum after all, so maybe I posted in the wrong bit if I was worried about integrity of the building!

 

[endecotp]

Any cracks in the outside wall, or anywhere else? Maybe downstairs?

 

[sandblast]

Any cracks in the outside wall, or anywhere else? Maybe downstairs?

hiya, none at all as far as i'm aware, i checked thoroughly when i bought the place in 2023. i work in property insurance and see subs claims every day, so was very vigilant about that. having said that, shortly after moving in i did remove a row of leylandi trees that were about a metre from the building, but that was on the other side of the building. i will have another look at the walls outside and in the downstairs flat later on. it's worth double checking this before i do the repair job. thanks.