Roof for factory office

[terryhawkins]

We have just moved into a new business premises and have built two offices inside the factory.

However, we're after an idea into what to use for the roof. It needs to be quite well insulated from noise and the cold of the factory.

Naturally we can't spent a fortune, but anything at a reasonable cost will be considered. Any ideas would be greatly appreciated.

Photos of the office are below...

 

[^woody^]

Normally, you span some joists across and plasterboard and skim the ceiling. You can put some rockwool across the top is you like.

Don't forget your fire precautions - protection, warning and detection, and your escape route.

 

[terryhawkins]

Thanks for your reply.

Would the joists be sufficient to support the weight of the plasterboard?

The only reason I ask is because the span from wall to wall is approx 9m, and there is a partition wall in the middle (4.5m each side).

Would we need to go from wall to wall or would the centre wall (as you can see in the first photo) be strong enough to support the full 9m span.

 

[RonnyRaygun]

Thanks for your reply.

Would the joists be sufficient to support the weight of the plasterboard?

The only reason I ask is because the span from wall to wall is approx 9m, and there is a partition wall in the middle (4.5m each side).

Would we need to go from wall to wall or would the centre wall (as you can see in the first photo) be strong enough to support the full 9m span.

Yes, you could use the central wall as support - use 50x175 C16 @ 400mm crs, or 50x200 C16@ 600mm crs. There is a generous allowance in there for storage (75kg/m2)

There are sound reducing products available: http://www.soundstop.co.uk/soundproofing_ceilings.php

 

[terryhawkins]

Thanks, that sounds perfect, we'll do that.

Just one final thing... What type of joint is best to join the joists together?

At the centre wall we can just overlap the joists but in the middle of the room (assuming all are 2.4m) we would need a join between two to make 4.8m and span to the centre wall.

 

[RonnyRaygun]

You should be able to get joists at 4.5m long - it wouldn't really be practical to try joining short lengths mid span.

 

[cAtLeYx]

RonnyRaygun, I am by no means questioning your reply and bow down to your superior knowledge here. But, should the stud partition that has already been erected be considered here as part of the design?

 

[RonnyRaygun]

If I was designing a house I would be more concerned, but I did run a quick check, and as long as the stud wall is adequately restrained top and bottom, even 2 b 2 at 400mm crs will work for the loads in question. I did think the studs would have a larger cross section than that, but now noticed it is the wall in the top picture. I've also assumed a floor to ceiling height of 2.5m - looking at the door and top of wall this wouldn't be far out.

I should point out to the OP that the stud wall should be sheathed both sides (plasterboard will be fine), and well connected to the floor and supported joists.

It's surprising the loads that stud walls can take - I did a six storey building at my previous practice.

 

[^woody^]

I did a six storey building at my previous practice.

I did one more, but that's another story.

 

[RonnyRaygun]

I did a six storey building at my previous practice.

I did one more, but that's another story.

 

[terryhawkins]

Yes, you could use the central wall as support - use 50x175 C16 @ 400mm crs, or 50x200 C16@ 600mm crs. There is a generous allowance in there for storage (75kg/m2)

Would 50x125 C16 at 400mm crs be sufficient if we have no allowance for storage?

 

[RonnyRaygun]

Yes, you could use the central wall as support - use 50x175 C16 @ 400mm crs, or 50x200 C16@ 600mm crs. There is a generous allowance in there for storage (75kg/m2)

Would 50x125 C16 at 400mm crs be sufficient if we have no allowance for storage?

Assuming you have no boarding on top and never use the roof for storage you would get away with 50x150 @ 400 crs, or 50x125 @ 250 crs.

Anything less and your ceiling is going to sag noticeably...

 

[theprinceofdarkness]

Use a suspended ceiling, suspended from your ceiling.
Frank