How to resize and cut a hole in plasterboard for ceiling fans?

[Razor20]

I have a need to replace 2 ceiling exhaust fans with lights in bathrooms.

The hole in the ceiling is 24cm x 24 cm. The original Domus fans were installed when the house was built in 2007. 

Replacement exhaust fans from what i have now found require a circular hole which is available in 24cm diameter.

It would be easy if i was going from a circular 24cm hole to cut a 24cm x 24cm hole.

At this stage my option appears to be to repatch the  hole which will then require sanding, and painting so that a new 24 cm circular  cut out can be made to instal a new 24 cm exhaust fan. I have looked on the net and have not found suitable conversions kits.

I would expect my task it not new, and i would appreciate feedback if there are smarter options to do this job.

Regards, Razor

 

[EricL]

Hello @Razor20 

Thanks for sharing your question about resizing a cut hole in your ceiling. I recommend patching the hole with a piece of Gyprock CSR 530 x 530 x 10mm Mini Plaster Repair Panel. However, I suggest reinforcing the corners with some 42 x 19mm 1.2m DAR Pine Standard and screwing them in with Zenith 6G - 18 x 30mm Needle Point Gold Passivated Plasterboard Screw - 100 Pack.

I've placed a sketch below of how to repair the plaster. The general steps are to cut a repair piece to the size of the square hole. Add reinforcing timber to the corners and cutting the circular outline on the repair piece before gluing and screwing the corners in place. 

If you need further assistance, please let us know.

Eric

[Razor20]

Thank you Eric for your detailed reply.  
I expect this question has been asked before. I will go ahead and follow your guidelines. 
Cheers Razor

[EricL · Accepted solution]

Hi @Razor20 

It is a popular repair topic, however, almost every situation is unique. My best suggestion is to make sure that the new ceiling exhaust fans locking clips will not hit the support timbers you've placed in. Please doublecheck your fittings before permanently installing the repair piece in place.

Since you'll be working at height, please make sure to read this guide - How to use ladders safely by @Adam_W.

Please remember to wear personal protection such as gloves, goggles and a mask while repairing your ceiling.

If you need further assistance, please let us know.

Eric