Crack under winfow on extendion

[danoid]

I have a crack under the extension window.

I chipped the plaster away and the block itself has cracked, breeze block i think.

I filled it in a while ago with just normal filler, but its come back again on the bit i repaired, hairline crack. Somedays you cant see the crack and others it shows as hairline again.

Obviously i need to fix it correctly, is there some kind of strong repair method i can use, mesh? If so how do i apply it?

When the extension was done in 1997, the windows were done and had several large gaps, which ive filled up so should stop the cold getting in, doen the bottom it looks like there is mortar missing in a brick which i need to fill, as cold is probabky getting in, doesnt help the room gets to 11oC sometimes.

What do i use to fix it,

Thanks

 

[Alastairreid]

Google expamet lath.

 

[ree]

Sounds as tho you have thermal movement - best not to fill the internal crack but do as suggested above.

For the outside crack you would usually lightly clean out and fill with polysulphide caulk (i think thats the name, but check).

However, you should post pics of the window gaps and the missing brick.

 

[danoid]

There is no crack on the external brick wall, just the internal one.

Regarding the mesh, is there a correct way to do it?

Guessing, chip plaster away, put mesh over crack, screw in to block, then refill?

But won't screwing into the brick cause more damage?

From the looks of it I think there called thermalite, got the same pattern on atleast

 

[ree]

Yes, chip off plaster back to thermalite block, and nail - use clout or roofing nails with a large head - a strip(s) of mesh over the crack then patch up.

 

[danoid]

Excellent thanks for that. Want to get it sorted before we get a bigger radiator installed