Hi

I have a room measuring 5.2m in length x 3.1m wide. At present the room has a cement ceiling.

I am wanting to install downlighting and therefore require to place a false ceiling with a 140mm cavity, enough room for the heat to disipate (i think this is a UK legal requirement).

I am proposing to fix 2"x4" (or metric 5cmx10cm) timber around the perimeter of the room as the plates. Then with 2"x4" run timber struts across the width room (the 3.1m lenght).

To this timber structure i would attach 9.5mm plasterboard and skim.

My questions are i guess
1. Is this the best way to install a false ceiling
2. Is 3.1m too long for 2"x4" wood, or will is sag in the middle (i am a little worried about the wieght to go any larger)
3. Will i need something in the center of the struts bolted to the ceiling to take the weight, and how would i fix this through the concrete.

Thanks for any advice that can be offered.

Chris

#1 Thats the way I would do it.
#2"x4" is fine for that span.
#3 No!

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By eck!

id run noggins through a metre in from each edge too just incase of any twisting. or perhaps just 1 line through the centre of the room. depends where the down lighters are gonna be positioned.

Also, you need noggins to pick up the edges of the plasterboard

S

id only run one row of noggins down the centre.

I'd run one row at 1220mm centres from wall and another at 2440mm to pick up boards.

It's not like it takes long to bung them in

Don't waste time and money by putting a suspended timber framework for the new ceiling.

It will be a lot quicker to put an MF ceiling grid up and board onto that. use Taper Edged boards and then tape and joint the joins.

An MF ceiling grid consists of a perimeter trim screwed to wall, hangers, main channel every 1200mm and then a tophat channel spaced 400mm centres which runs at right angles and gets clipped to the main channel.

You would have it ready to receive plasterboard in about 3 hours.