Plasterboarding Stone and Blockwork Walls

[AndrewSchofield]

I'm just about to start plasterboarding out in my loft which we are converting to bedrooms. Is it best to use the metal beading for corners or i've seen some flexible metal plasterboard corner tape that is supposed to eliminate the use of beading - anyone know if this stuff is any good?? Do i need to fix beading in internal corners and where the walls meet the ceiling or just external corners??? If i don't use the metal tape how do i fix the beading - i've seen some people use adhesive and some say use a staple gun?

 

[Richard C]

Assuming your going the get the plasterboard skimmed, use a thin metal angle bead on external corners. I fix this with either a staple gun or small dabs of grab adhesive or sometimes both; a staple gun is quick & works well on PB but not so well on existing plaster. I don’t use anything on internal corners except window reveals where an internal stop bead against the frame makes life a whole lot easier! It’s not normal to use a stop bead on internal corners, if your plasterer is any good, he won’t need it.

 

[AndrewSchofield]

Cheers Richard,

Another thing you may be able to help me with - most of the plasterboard is going on timber studs so i'm happy with that but i've got a small section of concrete blockwork wall which i intend to dot & dab onto and then the party walls which are rough limestone walls, is it best to fix battens to the limestone wall or can i dot & dab these too??? Will i need more 'dab' to account for the fact that the walls are not as even as they need to be? Do i need to prepare the blockwork/limestone before dotting and dabbing?

 

[PlasterboardLifta]

Andrew, concerning the limestone wall, just get British gypsum Dri-wall adhesive. Put your dabs on like a stud frame.
| | |
| | |
| | |
| | |

As Above, then just stick your board on to it, use a spirit level to get it straight

You dont have to apply anything to a limestone wall before dot-dabbing.

 

[SimonWraight]

You should use fibre tape on the internal corners and where the plasterboards meet any walls. This is to help reduce cracking.

 

[AndrewSchofield]

PlasterboardLifta,

Thanks for that, do i need to apply anything to a concrete block wall then before dot and dabbing?

Cheers,

 

[Richard C]

Sorry I didn't get around to replying to you earlier. Not sure if plasterboardlifta intended his sketch to be diagrammatic but on a standard 2.4m x 1.2m board I would space the dabs much closer together across the width of the board than shown. I’ve not dab’d in strips like that before but I’m unsure if it’s a recommended method for use on Limestone which I’ve no experience with! I space dabs using a wooden cooking spoon (gives a good, uniform sized dab) at around 250mm apart but no more than 300mm; around the edges of the board, I put an extra dab in between to give good support.

You don’t need to seal the concrete block wall beforehand.

 

[roy c]

You can never have too many "dabs" but you can have too few.........

 

[AndrewSchofield]

Cheers everyone for you help,

With regard to the limestone walls, they are over 100 years old and while they are sound they have built up plenty of dust in that time. I assume the dry wall adhesive wont stick properly to this so i'll have to clean the walls first? Any suggestions to best method - do i just brush it all off or run over the walls with an old vacuum?? Some suggested this weekend that i 'paint' the walls with SBA mixed with a bit of cement to sorth the dust out but reading posts on here i'm not sure that necessary?

 

[Richard C]

I’ve no experience with D&D onto limestone walls which, by the nature of the material, I assume would be very porous; unless anyone else can advise for sure, I would say just seal it the day before with 2 coats of PVA!

 

[AndrewSchofield]

What exactly is PVA?? I've read others talking of it but my only experience of PVA was glue at school?? Or is that the same stuff????

 

[Richard C]

What exactly is PVA?? I've read others talking of it but my only experience of PVA was glue at school?? Or is that the same stuff????

Same stuff as far as I know;
http://en.wikipedia.org/wiki/Polyvinyl_acetate
You can buy proprietary sealers & bonding agents from the plaster manufacturers whose blurb would seem to indicate it has additional, “magic” ingredients that make it more suitable; never tried theirs but I suspect it’s basically formulated from PVA & twice as expensive.