Cracks in the garage wall - supporting wall

Doozergirl

info_maniac wrote: »

I'm not too sure which one is the load bearing one - outer or inner. From this picture, it appears to me that it is the inner wall which is load bearing, and cracks (ceiling to floor vertical cracks) in a load bearing wall are surely a matter of concern, right?

They both bear load but it's the outer wall that has the most strength unless the Thermalite blocks are upgraded ones that take specific load. The markings on your blocks indicate that they are standard 3.6N/mm2 blocks. Those blocks are used because they are aerated, have good thermal and waterproofing properties, not primarily for strength. I'm not a specifier, but when we're building load bearing walls, they're at least 7N/mm.

If the outer wall is cracked, that's when I'd be worrying.

I told you in post 2 to contact a structural engineer, people have subsequently told you that Thermalite blocks cracking is not an unusual thing and yet you're still trying to self-diagnose with no qualification to do so.

Slinky

I think you're confusing yourself with modern timber framed walls where the bricks are aesthetic. The picture you have posted is brick and block which is a different technique.

stuart45

The wall plate which takes the weight of the roof normally sits on the inner block wall. A brick wall is normally stronger than a block wall because of the bonding of the smaller units. The wall ties connect the 2 together and form a stronger wall.
You sometimes find on site when the blocks are straight from the works they are still a bit damp and a bit heavier, and the cracks in walls built with these are showing before the walls are plastered. With dot and dab you can't see them.
Cracking can usually be avoided by using a weaker mix, adding bricktor in the joints and using movement joints on longer runs.
I have worked on jobs were the external brick wall was removed and rebuilt leaving the inner skin the hold everything up.

ToasterScheme

Doozergirl wrote: »

They both bear load but it's the outer wall that has the most strength unless the Thermalite blocks are upgraded ones that take specific load. The markings on your blocks indicate that they are standard 3.6N/mm2 blocks. Those blocks are used because they are aerated, have good thermal and waterproofing properties, not primarily for strength. I'm not a specifier, but when we're building load bearing walls, they're at least 7N/mm.

If the outer wall is cracked, that's when I'd be worrying.

I told you in post 2 to contact a structural engineer, people have subsequently told you that Thermalite blocks cracking is not an unusual thing and yet you're still trying to self-diagnose with no qualification to do so.

Both faces bear the load of the first floor wall above, but doesn't the inner face also carry most (if not all) of the weight of the bedroom floor/contents also? And perhaps ultimately the weight of the roof too?

I thought lintels were generally biassed to give more support on the inside for this reason.
[Just curious]