To bolt or not to bolt into concrete lintel?

[Rick734]

Morning folks,

 

Hoping for some assistance with this one, I need to bolt a ledger plate to the front wall of the house to take the roof joists for the new porch (which is approx 7m long x 2m deep i.e. not massive roof load). My problem is that at the height I want it, the ledger plate sits partly in front of an existing concrete lintel which I'd need to bolt into (as well as the wall above) to secure the wall plate. Lintel is pretty massive at around 280h and 240d and I'd only need to bolt into the top half of it...anyone know if that's a good idea or alternatively if there's a better solution? 

You can see most of the height of the lintel below the unfixed wall plate (which needs to drop down a bit further)...

[Rick734]

[Russell griffiths]

What does the lintel span, if it’s only a short opening then I think the risk of damage to the lintel is minimal

 

i would use a resin and threaded rod not a bolt that expands. 

[joe90]

1 minute ago, Russell griffiths said:

would use a resin and threaded rod not a bolt that expands. 

+1

[Rick734]

12 minutes ago, Russell griffiths said:

What does the lintel span, if it’s only a short opening then I think the risk of damage to the lintel is minimal

 

i would use a resin and threaded rod not a bolt that expands. 

Thanks, it spans approx 3.6m which is the opening from the porch into the hall. Happy to go the resin route, was just debating the pros and cons of either so thanks.

[Russell griffiths]

That’s a big opening 

I might stop and re think this situation, we don’t know enough about the whole job. 
 

can you not enlarge that timber so it spans the same opening and only needs the fixings into the brickwork above. 

[saveasteading]

Ahhh. precast lintels usually have tensioned wire in them. cut that and it loses lots of the strength.

I think (!) the wires are in the middle, so drilling at 1/4 to 1/3 points might be safest. use the smallest fixing that will work x maybe more of them.

I agree threaded rod and epoxy.

1 hour ago, Russell griffiths said:

I might stop and re think this situation, we don’t know enough about the whole job. 

agreed. Is there another way?

[Rick734]

Thanks Russell/Save, it is a decent size opening and agreed definitely not ideal to drill into it. Might be able to keep the ledger plate high enough to just fix into the blockwork if I can use long leg joist hangars to drop down to the right level - any idea if that's acceptable? I guess they'd be hanging down off the bottom of the ledger plate by approx 150mm to get the heights right...maybe could fix another piece of timber to the bottom of it for extra strength/rigidity...does that make sense? 

 

Something like this: 

Edited September 19 by Rick734

[Rick734]

Just to clarify - the main fixing point for the joist hangers would still be in the main ledger plate, but there'd be a few nails into the bottom fillet piece for stability and extra strength. Id attach that piece of timber with straps/plates or long screws up into the bottom of the actual ledger plate.

[Mr Punter]

Could you use some masonry hangers onto the top of the lintel and lose the ledger plate?

[Russell griffiths]

Double or triple up the ledger and make it more of a structural item, support it from both ends, and bolt to the wall. 
 

without proper pictures or diagrams it’s hard to say, is this just a small flat roof. 

[Rick734]

14 hours ago, Mr Punter said:

Could you use some masonry hangers onto the top of the lintel and lose the ledger plate?

Potentially, but my understanding of a masonry hanger is that it's bedded in and nailed down through the top, before the brickwork above is laid... so not very feasible?

[Rick734]

@Russell griffiths Images attached - overall porch size is 7.2x2m approx. So pretty small as flat roofs go.

Having looked at it last night I think I might go down the route of lifting the ledge plate just enough to get all fixings into the blockwork, and then use a long-leg joist hanger to drop down below the bottom of it to take the roof joists at the right height. Sound sensible?

[Rick734]

e.g. similar to this image: 

Edited September 20 by Rick734

[Mr Punter]

8 hours ago, Rick734 said:

Potentially, but my understanding of a masonry hanger is that it's bedded in and nailed down through the top, before the brickwork above is laid... so not very feasible?

 

I understand you would cut a slot in the mortar bed, clean it out, gun in fresh mortar, dip the tangs of the hanger in the mortar and insert.  Masonry hangers don't get nailed down through the top.