At last a voice of sanity. I trust the squabbling kids have moved on.
*********************** Firstly, I hadn't seen the row at the bottom of the PDF which gave a load in Kg per metre. This would have made things a lot easier.The application is a lintel to go over the top of two doors and two windows in the Mother of all Sheds. They will be part of the ultimate block course and so be bearing little more than the weight of the roof and joists. The window span is 900mm. The door span is 1650mm. The loading figure given for P100 is 14.27 Kg/metre. This suggests that it would bear the weight of roof joists and roof but might not be adequate on its own to support the load of an 80Kg adult on a single joist hung above the lintel.
************************************** Edit - I've left the above in to show what I thought on first re-read.Looking at it again this is the weight of the lintel itself, per metre, 'to be subtracted from the load given'.
"You seem to be mis-reading the manufacturers data. They've provided a table giving the safe uniform working load a lintel can take for a particular lintel size and clear span. If the load isn't uniform then they've provided the equivalent service moment. If you don't understand the figures then it probably means you need someone to assist you. " where is this information about the safe uniform working load? Or has Roof mis-read the table?
All I can see at the moment are figures for lintel weight and Service Moment. I presume that in taller walls a lintel has to support the triangle of blocks/bricks directly ove the lintel which are not self-supporting. In this case there would be 2/3 of a block course then a wall plate above the lintel. The joists would be on hangers off the wall plate. So for the door the combined strength spreading the load would be the wall plate above 2/3 row of blocks above the lintel (which isn't quite touching the top of the door frame otherwise that would provide some additional support).
I now have two other pieces of advice:
"Multiply weight in Kg by 9.81 to get Newtons" "One KN is about the force you get from 100Kg weight" Which don't seem to agree.
100Kg * 9.81 is approximately 10 Newtons? Which would be 0.01kN?Or 100Kg = 1kN?
For the 2.1m P100 on a 1650mm span with a figure of 3.33 kN this is either:
100 * 3.3/0.01 = 33,000Kg (!) or 100 * 3.3 = 330Kg.Hopefully the lower figure is still accurate because a load of 330Kg per metre should support even my weight. This is about 17 concrete blocks per metre and I think a course would become self supporting at less than 8 courses high over 1.65 metres.
If there is another order of magnitude difference then 33Kg is just about useless given that an individual concrete block weighs 19Kg and you lay just over 2 to a metre!!.
So, bottom line is the lintel is across a void and intended to support a metal sheet roof on wooden joists with the ability to support an adult male on the roof above the void. About 2/3 of a course of blocks and a wooden wall plate will be above the lintel.
Assuming the 330Kg/metre is accurate then the P100 should be fine, especially with the additional strength of the wall plate.
And it is, afer all, only a f*cking shed.
Cheers
Dave R