what sort of steel lintel would suffice?

[jontop]

it will be supporting 2mx3m thermolite type blocks , which are 3" thick and half inch sand cement plaster on both sides, no other loads.
the lintel will be 2m long and of course needs to be only 75mm wide.
I thought a catnic or such box lintel would be ample

 

[tomfe]

Yes or concrete on it's side

 

[tony1851]

Yes or concrete on it's side

Hmm; what size?

 

[jontop]

in the backof my mind somewhere there is a limit to the length of concrete?

 

[jontop]

75mm steel box lintel hard to find , maybe special order

 

[tony1851]

How about a 127 x 75 steel beam? Should be cheap enough and easy to find; 2nd hand?

 

[jontop]

Good, found a local steel man. 127x76mm steel beam cheap enough
Now the blocks are soft type so will need padstones or steel plates
Which is best for my situation? Pros and cons of each?
Padstones seem to start at 100mm wide, I assume I can just cut them down?

 

[themiddleagedun]

Padstones aren't required as the beam is only used as a normal lintel..

 

[tomfe]

Hmm; what size?

Well with 150mm on both sides and a 2m span 2.3, but since you can't get that size get a 2.4. The load is small soba 100mmx65mm will do.
Same as a standard box lintal, the span and loads are small you don't need a UB.

 

[tony1851]

Hmm; what size?

Well with 150mm on both sides and a 2m span 2.3, but since you can't get that size get a 2.4. The load is small soba 100mmx65mm will do.
Same as a standard box lintal, the span and loads are small you don't need a UB.

Personally I doubt that would work.
Even if you turn the concrete lintel on its' side (so that the depth is 100mm), that is still a span/depth ratio of 20, which is just too much
for concrete.
Additionally, those lintels at that length are susceptible to being cracked while handling. Just too risky IMO - steel is the way to go.

 

[tomfe]

Just too risky IMO

Those damn foolish manufacturers, what are they thinking!