How to repair plasterboard after insulation installation?

[tarragindi_haus]

Hi

I'm looking to install insulation into exisiting walls of my house.  As part of this, I will look to remove the existing plasterboard walls, up to 100mm below the ceiling and beside the architraves.

My question is around joining the new plasterboard to the old.  As these will be butt joins with no studs behind the joints, will I need to backblock all of the sections where it joins?  Or is it sufficient to just tape and set the joint?

Thanks!

[EricL]

Hello @tarragindi_haus 

I suggest back blocking all the sections of the joins to make sure the ends are fully supported and level. I only suggest it as some parts of the older plasterboard might not be level and the ends will not line up. Before you begin if you your house was built between 1970-1980, I suggest having your walls tested for asbestos. If the results are positive, you'll need to engage the services of an asbestos removal specialist. If the results are negative, you can continue your renovation plans.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

[Dave-1]

Good Morning @tarragindi_haus 

I always think its strange when something I have been doing (reno wise) then pops up in my Bunnings questions

I have just spent the last week renoing my foyer and hallway. I had two holes and a lot of straight cracks from old repair panels. 

The reason I am telling you this is even though I sanded it all smooth as I still ended up with seeing some edges, except for the hole I repaired via some timber glued to the backside of the hole. That came out perfect. The one where I used existing timbers to support the patch, you can see it just.

So I would definently block it (or glue support timbers behind it to give support to that join I had a LOT of sanding to do, not just plaster but sanding back poil based paint and flaky paint.

I also supsect that what @EricL has mentioned about different sized plaster may also have been at play. (I should have down it properly )

Dave

[Nailbag]

Hi @tarragindi_haus 

Unless you have the skillset to repair all the joins seamlessly, then my first port of call would be to get quotes from plasterers. I expect it will end up being cheaper with a far better finish to remove the walls completely including the cornices and start fresh. Repair work can often lead to more time and money and in this case will not have the same finish, especially on any walls you look down along like hallways.

If you like a more modern square-set finish, then it will be cheaper again without the added cost of cornices and its installation. That would be my personal preference.

Nailbag