I am one day into have a loft conversion completed on a modern trust
rafter house by a specialist loft conversion company. They ran into a
few problems, which they are doing there best to sort out, but it lead
to be to have a good look at he work completed so far.
I have a couple of concerns about the steel trimmers they have put as
the new supporting members across the width of the house. One of the
steels (I beam) is 30cm high and 6 meters long. One end is supported
on an internal load bearing wall and that looks fine, but the other
end is supported on the external wall.
The 'stack' goes like this: I beam 300mm high, 6 meters long, cut at
45 degrees (to fit under tiles); 30mm thick, 100mm wide, 400mm long
steel plate; 60mm thick, 100mm wide, 400mm long new timber member (to
raise height); existing wall plate (I assume as I can't see). The
concern is that the overlap of the I beam onto the steel spreader
plate is only 50mm. The architects drawing shows a square ended beam
(ie not cut at 45 deg) sitting a full 100mm on to the steel plate.
I also believe there should be a 25mm gap between the steel and the
existing timber ceiling joists - is that right? If so I have less
than 10mm - the builder said no, that is only between the new floor
joists and old ceiling.
Should I be worried? What is the building inspector going to say
about A) the overlap and B) the use of timber in the 'stack' C) the
lack of gap?
Thanks in advance