Lintel on breeze blocks

[Sibin]

I am to open the wall between the kitchen and dining room. The wall is bearing the load of joist of a bedroom above it. There is no other wall above it nor stud wall just the joists.
I am looking at installing 2700x100x65 lintel. My question is what is the minimum length on the breeze block that the linteln must sit on? One builder said 145mm on each end is sufficient . Is he right?
Also, do I need block pads between lintel and breeze blocks? I know that breeze blocks or also called thermal blocks look light but they can withstand quite a weight, I am still concerned about 145mm.
Any help would be much appreciated.

 

[Deleted member 174758]

Yes, I think he is. Normally we work to 150mm at each end onto a concrete padstone as thermal blocks are somewhat friable and should not be depended on to carry the weight directly. In most cases the strength of the padstone and UB are calculated by a structural engineer for us.