garage ceiling issues.

[i_am_fubar]

I'm re-doing my garage and I have that nasty asbestos ceiling stuff. as much as I'd love to get rid of it. money, time, safety... etc.

Instead, I'm going to put another ceiling up. Current plan is:

1x6 beams for most cross members, 2x6 beams where plaster boards join so I can screw both up.

No real load to hung on them. am looking at this sort of plaster board:

http://www.wickes.co.uk/Plasterboard-95mm/Tapered-Edge-Plasterboard/invt/220207

My issue is beam spacing. what is the maximum dimensions I can have between joists without having to worry about the plasterboard breaking under its own weight?

I was thinking 1m by 0.75m would be sufficient.

Comments?

Cheers, Sam.

 

[noseall]

even if the ceiling is to be completely independent from the existing - meaning that you will not fix to the existing, then 6" deep timbers may still be a bit heavy.

then again i don't know what span you are dealing with!

i would not use anything that is only 1" thick though. i suggest ALL timbers be a minimum of 2" thick. as said earlier depth will depend upon span.

600mm centres is an accepted maximum spacing.

use 12.5mm boards, they offer 1/2 hour fire resistance.

 

[i_am_fubar]

12 hours? wow, thats impressive. To be honest, I'm not massivly concerned about fire hazzards *touches wood* as I said, I'm only interested in having something that is there for show. the asbesos will give the fire protection.

I'm also using it to susspend floresent lights.

Upon doing some CAD work, the spacing between the main timbers is 600mm. so yay. Will probably space at 600x500 ish.

What is the reason for wanting the 2" all over? strength, or accuracy when screwing into them? I'm really trying to cut as many financial corners as I can while still remaining safe and alive.


max span, across garage is 2500mm.

 

[noseall]

use 4"x 2" at 600mm centres.

use a midspan noggin (solid bridging) to add a bit of stability.

i personally think 9.5mm boards are flimsy, but that's just my opinion.

2" timbers will offer more meat in which to fix, 1" leaves little room for error and is more prone to misshaping.

half hour fire resistance not 12 hours!

 

[i_am_fubar]

ahhh, 1/2 hour. ok, that makes more sense. >.<

just to verify. I know I'll need 2500mm spans every 600mm. Are the noggin's the following:

without:
|==========|
|==========|
|==========|
|==========|
|==========|

with:
|==========|
|====|===== |
|==========|
|=====|==== |
|==========|

If so, is only one center noggin needed?

Cheers,
Sam.

 

[noseall]

a series of noggings across the centre span will work fine.

they must be as deep as the timber being used, or at least braced top and bottom (usually only applies to deeper timbers and known as herringbone strutting).

we offset or stagger each timber noggin, either side of the central line, so that the ends of every noggin can be nailed. i think this is shown in your diagram.

 

[Deluks]

What is currently holding the asbestos sheets up? Can you not fix to that?