Ledger plate bolt spacing?

[hexdex]

I've searched as best I can, but can't find what the recommended bolt spacing is for attaching a ledger plate to a wall. I am using a 6 x 2 joist as a faceplate for a suspended floor spanning 3.5 metres with support in the middle. I plan on using some M10 x 140 throughbolts but have no idea of the best spacing. Also, would these be in pairs or in a W shape?

Thanks

 

[ree]

Is this for remedial work in the ground floor sub-floor wall(s)? Or for new work in an extension for instance?

 

[hexdex]

Hi Ree. It's a little office I'm building in a small granite wall outbuilding. The floor is concrete, but incredibly unlevel. So I'm going to do a ledger plate with suspended floor.

 

[^woody^]

One every 500mm along the centre line will do.

 

[noseall]

Every 600mm staggered.

We fix ours with screws first in any case. We fix the joists then use expanding bolts in between the joists so that none of the protruding fixings can clash with the joists.

 

[hexdex]

Wow, thanks guys. I was thinking more like 2 every 4-500! It's a really uneven granite block surface it's attaching to and I will need to pack it a bit as well as there won't be much flat surface to lay against. so given that, would it make much difference?

Are you on nights noseall, or just a bad sleeper like me?

 

[noseall]

Are you on nights noseall, or just a bad sleeper like me?

Early riser. Love mornings. Everyone else is in bed and I can get work done.

 

[hexdex]

Yeah, I know what you mean. I hate getting up early as that's the best time I sleep ironically, but I do like it when I emerge.

Do you think the uneven surface would require more anchors given that the ledger won't lay perfectly flat the whole length?

 

[^woody^]

Push some mortar, knock some wedges, or squirt some foam into the gaps if they are more than 10mm, to stop the board twisting. No need for extras fixings

 

[hexdex]

Thanks woody. I was thinking about filling the voids behind with mortar anyway, so it seems it was a good idea then. I don't have many of those!