In an earlier contribution to this discussion,
Pecanfan wrote:

Hi all,

I've got another joist question that I'd appreciate a few comments on,
totally separate to my various 'loft' posts.

Basically, in case you hadn't already read in another post, the back
of our upstairs flat currently has it's exit to the rear yard
downstairs, i.e. the stairs are inside the flat and eat up a fair
portion of, what will become, our new kitchen. The plan is to move
the door from downstairs to upstairs and bolt a new metal fire escape
on the back of the house. I can then fit a new floor where the
stairs used to be and all will be dandy.

Well, after a weekend of knocking various holes in walls to see how
the joists run, this would appear to be the situation:-
http://www.pciq.co.uk/pics/joists1.gif

Now, obviously I need to somehow put a floor where the current
staircase is, however I have a number of dilemmas:-

1. I can't disturb the existing floor joists since they support our
downstairs neighbour's ceiling and I don't really want to be stung
for a replastering bill.

2. Joist A would appear to be supporting half (?) of the weight of
the current floor and ceiling via Joist B, so I don't want to put any
extra weight on Joist A OR B, which rules out simply shoving some new
joists in and hanging between the wall and Joist B.

3. Likewise, I can't really run a couple of longer new joists
perpendicular to the existing joists, suspended between the back wall
and Joist A, since again I would imagine Joist A would be supporting
too much weight.

4. I can't up-rate Joist A with steel on the back, since there's a
concrete floor behind it.


SO, the only thing I can think of is to do this:-
http://www.pciq.co.uk/pics/joists2.gif

Basically, I'll install a temporary joist from the back wall to the
concrete floor and fasten the existing joists to this using twisted
restraint strap. This should provide enough support to stop the
ceiling from collapsing while I remove Joist B. I'll then just bolt
new joists to the existing joists and remove the temporary joist once
everything is secure.

Can anyone think of any problems with this or does anyone have any
better ideas?

All of the joists in question are 65 x 175mm and the span from left
to right is 2370mm. I tried downloading SuperBeam but it makes no
sense. :-)

As a side note, if a joist hanger isn't quite at the right height,
which of course it will be, what's the best way of 'packing' between
the joist hanger and the joist to bring the joist up to the perfect
height? Slate?

Anyway, cheers again in advance!

Andy
new SDS drill has just arrived... REALLY feel the need to damage
something...

I think I would be looking to double up Joist B, rather than removing it -
and then put some new joists from B2 across the stair void. What is the
thickness and level of the concrete floor behind Joist A? Could you bolt A
to the concrete, and thus make it able to support one end of B2?

As others have suggested, you may have some negotiation scope with the
downstairs owners (new if not current) concerning what happens to the space
currently occupied by the stairs.
--
Cheers,
Set Square
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