Do i Need pastiness for 1200 concrete lintel?

Yes.

They help to spread the weight/ load.

Add more when I'm home in a hour.

 

I'm not a expert, but I would say it's only 1200mm, so debatable.

Mr. HandyAndy - Really

 

They serve a purpose of distubute the loading over a wider area,even more important where you have a old wall made from bricks of unkown strength, there could be the risk of the bricks crushing under the load, the padstones prevents this.

I've done jobs where I have remove four to six courses of bricks where padstones will sit & rebuilt with engineering bricks, to ensure a structrally sound wall for the padstones to sit on.

You will definitely need a padstone on the celcon block end & I would remove a couple of the celcons & rebuilding with engineering bricks where padstone will fit.

 

See this image, it a rsj use, but it's the same method when usingh a concrete lintel.
They have remove the celcon blocks & rebuilt with engineering due their strength & help to distruute the loading better.

 

It's only 1200mm wide though, KIAB. Surely, the bricks above that will be almost self-supporting?

Mr. HandyAndy - Really

 

Oh, and in your picture, there's no padstone, is there?

Mr. HandyAndy - Really

 

Yes, it's the lighter grey colour block supporting rsj.

 

Green arrow showing padstone.

 

I thought padstones were supposed to be slate or metal!

Mr. HandyAndy - Really

 

No no handy A bit like a standard brick, but a bit more of a hard bar steward!

Compo on top of your lintel. Acrow into place. Bed your pad stone down as well. Next day pack gap with slate and remove acrow.

 

No HA.

Padstones are made from highly dense concrete with compressive strength of around 50 N/mm2.

Steel & slate is only for packing out, steel usually under rsj for shims, & slate under masonry.

 

I reckon it's close to 200mm, but camera angle makes it look worse, agree though abit more length like 300mm sitting on padstone would be nice.

200mm should be ok, but I'm old school & always use to over engineered when doing lintels & padstones.

 

I am just DIY and I always over-engineer to be on the safe side. I am probably speaking too soon but nothing I have built has ever fallen down.
My joiner mate always says something like "You could have got away with using 4" x 2" " when I have used 6" x 3".

 

Depends on loading, every product has a newton load value. Yet you state its a lintel so no pad needed. if you stated a steel padstone yes. Usually done with engineering bricks

 

mixing materials isn't allowed on housing so this would fail inspection m8 sorry

 

Never in 30 years plus, have I ever had a BCO fail to pass my work.

Where I have put opening through old walls, with bricks of unknown quailty, I have alway part rebuilt the wall with engineering bricks where the padstone for the lintel,rsj is going to sit, & even with Catnic lintels, I still bed them on padstones.
I would never bed a rsj, lintel or catnic directly on to a Celcon wall, as in photo,I've done it that way & BCO's have always been complementary about doing it that way.