Creating bullnose corners

[jasnc]

Hello,

I'm interested to know proper techniques to make bullnose corners WITHOUT using metal beads.

We've had corners crack and im concerned with the order in which mesh was applied. It was applied BEFORE the plaster filling in the corner and the final coat. Is this okay or should the mesh go on later?

 

[Rhys]

Is this on board or S&C?

 

[jasnc]

Board.

 

[beddy]

board up to the corner both sides stopping just before the bullnose. then i'd make a ply jig and run it in bonding

 

[S a plastering]

Just leave the boards back off the arriss then you have 2 screeds to put a runner up just make a bullnose former then run your backing coat in

 

[DannyMac]

You wouldn't normally round a boarded angle. But I suppose a good way might be to leave both the meeting boards a few inches short, then create a round with bonding and a bullnose trowel.

I'd then scrim onto where the board meets the bonding on each edge.

 

[rockhardsolidplastering]

plastic bullnose beads or a bullnose tool.

 

[rockhardsolidplastering]

plastic bullnose beads or a bullnose tool. demandproducts.com

 

[Rhys]

My dad fabricated a bullnose tool for me years ago, 1/2" radius iirc as we had several barn conversions to do - all in S&C, and all at the back end of the year (bloody freezing that is..).When formed they skimmed up quite nicely by running a piece of polythene down them.

 

[jasnc]

Hopefully this will clarify.


The corner is already made up and now it has a vertical crack running where the board ends – so ¼ - ½ inch. My thinking is that this isn't well reinforced so its drying and causing the crack because the guy who did it put mesh down early. So what I really want to know is whether there's an order to laying the mesh (scrim?) to reinforce the corner so it won't crack. Should the mesh go on last before the final thin-wall is applied?

 

[beddy]

what mesh? you mean scrim? it should be on the joint after the corner is formed. if youre not sure what to do just mesh it with 100mm scrim all the way down and overskim

 

[jasnc]

what mesh? you mean scrim? it should be on the joint after the corner is formed. if youre not sure what to do just mesh it with 100mm scrim all the way down and overskim

Thanks, this sounds like the problem. Any more tips/info on this process would be greatly appreciated.

 

[beddy]

Thanks, this sounds like the problem. Any more tips/info on this process would be greatly appreciated.

run some 100mm scrim down it and overskim it

 

[Dansouthcoast84]

First time seen those beads.they look the nuts

 

[DannyMac]

Wonder how they'd paint up though. Don't think I'd want them in my house.

 

[Jace]

i usually scrim before the bonding so its bedded in to the backing coat then once again on the top before skimming

 

[Jace]

Wonder how they'd paint up though. Don't think I'd want them in my house.

do em right danny and they look nice mate had to do some a little while ago on a kitchen extension on the knock through wall big splayed angles in the corners looked really nice wen we returned to do the rendering and the inside had been painted

 

[DannyMac]

i usually scrim before the bonding so its bedded in to the backing coat then once again on the top before skimming

Why not scrim after you've skimmed too, just to hold it all together?

 

[Rhys]

Wonder if anyone does it the old fashioned way with the wood doweling?

 

[jasnc]

i usually scrim before the bonding so its bedded in to the backing coat then once again on the top before skimming

And I assume its necessary to scrim again because what you did before bonding wouldn't be enough? Could cause cracking like in my situation.

 

[keithuk]

Wonder if anyone does it the old fashioned way with the wood doweling?

or a Tesco bag ??

 

[Jace]

Why not scrim after you've skimmed too, just to hold it all together?

better safe than sorry takes 2 mins to put some on top of the bonding:RpS_thumbup:

 

[malc]

it all depends how large of bullnose angle that you require. the large ones about 4 inches 100mm we would turn with a straight edge [not a featheredge ]held in the upright position and turned by hand. finished with a piece of poly, wetted and folded in half to cover any rough edges. for the small bullnose tyzak did make an external trowel for bullnose