Garage ceiling on wrong centres

[dave_au]

Hi all,

I am new - please be gentle.

The gyprock ceiling in my garage has fallen down once before (few years ago) and is sagging again. I am told that this is because the gyprock is fixed to 600mm centres, when it should have been fixed to 450mm centres (on account of the moisture).

The first repair guys must have just replaced the gyprock without changing the rafters / centres, which I am guessing is why it is happening again.

This time round a guy has quoted me to add extra rafters to make it 450mm centres so that I won't have this issue anymore. Expensive.

I am wondering if I have any other options? Could I use MDF (or something else?) on the existing rafters? I could live with the strips between MDF sheets if I knew that the problem wasn't going to come back again (and if it would be cheapers than new rafters).

Thanks,
Dave Taylor
(Tuart Hill)

[journeyman Mick]

You can fix 13mm gyprock to ceiling battens @ 600 crs. I believe there's also a 10mm grade specifically for ceilings which can go 600mm also (but I may be mistaken there).

Mick

[rod@plasterbrok]

13mm and 10mm ceiling board, aka, superceil, span600, unispan, are all ok for 600 mm centers.

Boral have a specific fixing method for garages that includes additional fixings at the perimeter.

Garages are susceptible to moisture and wind when the door is left open, thereby placing additional strain on the product not normal inside a home.

This is a fairly common problem.

If you were to do anything I would batten the ceiling a 450 centers NOT add joists.

As a preventative method avoid leaving your garage door open on wet, windy or humid days.

Cheers Rod

[dave_au]

Thanks for your responses.

I have read up some more on the different products available (thanks for the list Rod). It seems that I should be able to get away with 600mm spacing on the framing.

The next question - given that the current ceiling is sagging but has not yet fallen down, could I get away with just re-fastening the existing sheets back to the joists? Or are they likely stuffed on account of the moisture?

The garage opens onto our courtyard - there is no door or wall here - just a really big opening. In the longer term, should I look at putting some ventilation into the roof space to try and reduce the moisture?

Thanks again.
Dave

[rod@plasterbrok]

I would always try re fixing it first before pulling it down.

I don't think venilation in the roof will help any. Plasterboard will soak up moisture in the air from the open door.

Maybe some of the painting guys could recomend a more suitable paint type that will make it less porous.

Cheers Rod

[Big Shed]

If it hasn't got a wall at the end it is more a carport than a garage, in that case I wouldn't use plasterboard on the ceiling again but something like Hardiflex.