On 03/06/10 18:24, 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 response, firstly I'm in S W Ireland where building
insp don't exist in the uk manner, secondly do you mean 6x3s just
instead of the doubleing up or for all the joists ?

Have a look at Appendix A in the old UK Building Regs Part A (Structure)
from 1992 - useful table of joist spans:

http://www.planningportal.gov.uk/PpW..._AD_A_1992.pdf

That suggests at the very minimum, you'd need 50mm x 195mm at 400mm
spacing. Can't see any way to do it with 150mm deep timber - you could
just do it with 75 x 170 (3x7").

You may need a more exotic solution. 4.3m is quite a long span and you
don't want that bouncing.

Flitch beams (steel/timber sandwich)
Engineered beams
Mid span support (RSJ)

could all be possible solutions. I think you need to be taking
professional advice.

Cheers

Tim
--
Tim Watts

Hung parliament? Rather have a hanged parliament.