In article ,
jim_in_sussex writes
Lobster wrote in message
news:innQd.195$a33.10
...
I bought some this morning from Travis Perkins, allegedly for 2" wide
joists, which is what I asked for (the receipt says they are 50mm).
However the actual gap into which the joist fits is only 42mm, which
means I'd have to trim 8mm off the joist width for them to fit.


Beware there are 2 types of joist hanger, one is made from quite
flimsy galv strip steel, the other from welded plate.

You want the last for *real* joist hanging ie to butt a joist against
a wall instead of inserting it into the wall.

I've never been completely clear as to what the flimsy ones are for -
maybe steadying butt joints between timber perhaps? Anyone any ideas?

Also most nominal 2in rough cut joists are not 50mm as you might
expect, but 47mm.

Its not a question of there being two types, there are different types
of hangar to suit different applications, if you look at the strongtie
site you will see many different types to suit different applications,
generally the heavier duty ones are for masonry fixing, the lighter duty
for timber fixing and don't forget to notch the end of the joist if you
are fixing plasterboard so that it fits flush.
--
David