"Hugo Nebula" abuse@localhost wrote in message
...
[Default] On Mon, 13 Jun 2011 15:46:24 +0100, a certain chimpanzee,
"mark" , randomly hit the keyboard and
wrote:

So can anyone tell me a typical application for each grade of lintel?

It's to do with the loads on the lintel. The catalogues usually give a
safe working load (SWL). Wall loads are about 4.5kN/m^2, floors (in
dwellings) are about 2.0-2.25kN/m^2, roofs are between 1.5-2.5kN/m^2.
Multiply by the areas bearing onto the lintel, add a bit more to be on
the safe side, and you have you SWL.
--

I think I understand what your saying but working out areas is the tricky
bit for me. I can do the maths but determining the areas of wall and roof
bearing down on to the lintel is where I come unstuck.
Thanks

mark