On 03/06/10 18:41, rog wrote:
On 3 June, 18:17, Tim wrote:
On 03/06/10 17:51, rog wrote:

Hi I'm putting a new floor level in an old concrete block building. I
am intending to hilti bolt a 3 x 6 wooden beam on opposing walls then
using joist hangers on them joisting across ( 14ft 1in span, 18inch
spacing ) with 6x2 joists.
Any suggestions on dimensions and spacing of the hilti bolts, also am
going to double up joists where bath& water cylinder etc will be; is
it normal to have double width hangers for this or just bolt together
timbers?
I'm stuck with max 6in depth of joists as stuck for internal room
height.

First question - have you asked your building inspector (BCO)?

Second question - any reason for 6x2 rather than 6x3's? Just curious...

--
Tim Watts

Hung parliament? Rather have a hanged parliament.

Thanks for your reply, I'm doing this in SW Ireland where building
inspectors are not as in uk, if at all !
6x3s would seem good, would I still need to double up at bath etc
positions?

Ah... By SW, I assume you mean Eire?

With no disrespect intended, your reply worries me slightly as you seem
to be doing some serious structural stuff without the support of a good
set of plans. No rudeness intended - uk.d-i-y is here to help. But that
help might translate into "get a professional to advise"...

Anyway - 1st question: You presumably are/have to involve the building
control dept or whatever you call it? Will what you do be assessed by a
building inspector, prefereably before you start and at the end? Over
here (England) if it gets passed by the BCO you can usually be fairly
sure it isn't going to break.

2nd question: Just to be clear: 14' 1" (4.3m) clear span - and spacing
of 18" (450mm). My dormer conversion is 3.4m span and I have 8x2" joists
at an average of 450mm. That's why I mentioned 6x3's.

I'm not the person to say if this is good or not, but hopefully, someone
else can. Have you looked into Superbeam software (the author is on here
frequently) - that can help a lot with loading and bending calculations.

Regarding the bath and tank - I would expect a correctly designed floor
to cope, but you could always space those joists closer without going
for a full doubling up.

Have you got any other issues to consider, like resisting the spread of
fire between the floors?

Cheers

Tim

--
Tim Watts

Hung parliament? Rather have a hanged parliament.