Cut join at right angles to joists?

[davidp]

Hi,

Because of the shape of the room and it having a drop beam going down most of it, I would like to have a single cut join in the gyprock ceiling.

But this cut join would not be on a joist, it would at right angles to the joists.

Is this possible, and if it is, is there anything I should do first? Should I put in some timber backing for where the join will be?

Thanks

[rod@plasterbrok]

Do you have a fax?

If so fax me the room lay out and the joist directions etc with your proposed cutting plan. My fax is 03 9467 7647

I'm a bit confused because the joints should be at right angles to the joists. Not on a joist.

Also is the "cut join" along the length of the sheet or the end of the sheet.

Generally you need to have support along a join at 450mm centers for standard plasterboard and 600 centers for ceiling plasterboard. But at 300mm centers on a butt (cut) join. Then a put a back block over the join between the joists.



Cheers Rod

[davidp]

Thanks for the quick reply, Rod! Sorry if I have confused you.

Fax out of order but I have posted a drawing on imageshack. Might take me a few goes to get the link right.



One sheet of 1200x3000 will be uncut. The other will have to be cut along the long edge. So the joint will actually be butt against bevel.

[davidp]

Crikey, that picture worked. There's a first time for everything.

From what you've said, it sounds like I need a back block along that join. Running in a north-south direction in the picture. I shall do that.

Any tips for finishing the butt v bevel joint ?

Thanks,
David

[rod@plasterbrok]

Hi Davidp,

Put the cut edge agianst the wall, and the recessed edge to recessed edge.

It is not a good idea to have a butt edge against a recessed edge, this should be avoided wherever possible. It makes finishing the join too difficult.

Mix a "wet" mix to do the back blocking. Cut the blocks 150mm wide and just short of the length required. Put up the first sheet then spread the wet mix all over one side of the blocks and place them on the join over lapping. When you put up the next sheet the blocks will cover the join.

Clean off any mix that seeps through teh join before it sets to hard.

For tips on stopping up the join follow this link to my tips pages on my web site.
http://www.plasterbrokers.com/mpbdiyt.html#pb

Cheers

Rod Dyson

[davidp]

Thank you Rod, I really appreciate your advice.

Yes putting the cut edge against the wall is obvious now you mention it. D'oh!

Okay I understand about the back blocking. I had actually wondered about putting back blocks up without nailing or screwing them to the joists.

At 150mm wide, I'm guessing, are the back blocks simply offcuts of plasterboard? They seem too wide to be timber. And the weight of that much timber would be too much?.

Please let me know if I've got it wrong.

Thanks,
Dave

[rod@plasterbrok]

Yes, sorry I should have said they are off cuts of plasterboard.

Thanks dave.

Cheers Rod

[davidp]

Yes, sorry I should have said they are off cuts of plasterboard.

Rod you must wonder, just what sort of job such novices as me will do )

Gotta learn somehow. You've given me great advice - both here on this forum and on your site - and I'm pretty confident I can pull it off - which I wasn't before that.

Thanks again

Dave

[rod@plasterbrok]

Your welcome Dave,

Good luck with it.

Cheers Rod