Which type of basecoat and angle for Villaboard in wet area

[MichaelaG]

Hi everyone, 

This is my first post. 

I am about to start a bathroom renovation where I am striping out everything except the ceiling and bathtub. The house is brick veneer construction on concrete slab. 

I have watched the Bunnings video about how to install and stop up Villaboard in a bathroom and also read the James Hardie VIllaboard installation guides. There seems to be conflicting info on the type of base coat to use. I am pretty sure the ceiling is plasterboard.

The Bunnings video shows Gyprock Base Coat 45, the OEM documentation says to use the James Hardie Base Coat which is more flexible and suited to wet areas. 

I am tiling most of the walls however there will be some areas near the ceiling and at the wall to ceiling junction which will just be painted. I am also planning on doing a square set ceiling/wall junction (i.e. no cornice/architrave). 

I am hoping you can answer the following questions:

1. What base coat do I use on the walls (Villaboard)?

2. What base coat do I use at the ceiling/wall junction where villaboard meets plaster board?

3. What size and thickness aluminium angle do I use in the internal corners to install the Villaboard to the timber stud frame? James Hardie recommend 35 x 35 x 0.8 mm non ferrous angle, however I cannot see any products that are this thin in stock. 

Thank you very much for your assistance. 

Michaela

[EricL]

Welcome to the Bunnings Workshop community @MichaelaG. It's great to have you join us, and thank you for sharing your question about which basecoat and angle can you use for Villaboard in a wet area.

To clear out the confusion, if the recommendation is to use James Hardie Compound Base Coat 15kg Bag that is what you should use. The reason for it is because it has been tested as a combined system with the James Hardie Villaboard. I've spoken with James Hardie's technical department, I've been informed that you can use a wet area sealant such as Selleys 300g White Wet Area Waterproof Silicone Sealant between the plasterboard and the Villaboard. Your other choice is to use a setting bead which is a specialist product and may have to be purchased from a dedicated plastering store. 

It was also relayed to me that if the internal corner frame of the shower goes from floor to ceiling it is not necessary to have a bead in the corner. However, if you wish to put one in, it was suggested to use a non corosive angle made of PVC. I'll speak to some of the specialists at the store and see if I can get you more information.

Please keep us updated with your progress, we look forward to seeing the start of your bathroom renovation.

If you need further assistance, please let us know.

Eric

[MichaelaG]

Hi Eric, 

Thanks for such a quick and detailed response. 

I may need to reconsider doing square set corners at the ceiling wall junction unless I can get hold of some specialist bead given the silicone is not paintable. I do have about 3 tubes of the Selleys on hand though. 

Any further info on the angle would be great. 

Looking forward to stores reopening here in Melbourne this weekend. 

Will keep you updated on job progress. 

Thanks again. 

Michaela 

[tom138]

Hey @EricL,

I thought I’d hijack this thread rather than starting a new one. I am also lining my bathroom walls with villaboard and since my corners look like this (no blocking): 

I am assuming that I need to use corner angles. I initially purchased these: https://www.bunnings.com.au/siniat-28-x-2400mm-utility-angle-plaster-trim_p0730693?store=7363&gad_so... but it looks like they are not suitable for this application. Could you please suggest a product I could use? The JH wet area installation guide says that “Plasterer’s angle must not be used.”. Thanks, Tom 

[MitchellMc]

Hi @tom138,

I would suggest that the installation guide talks about an internal plaster angle on the face side rather than the utility angle you've selected for the rear side. As you can see in this guide, How to install Villaboard, that angle is exactly what you use to align the corners from the rear. This is to stop people from using the internal plasterer's angle and then setting over it with the basecoat; fibreglass or paper tape must be used instead.

For the front, you'll be using paper tape or joint tape and James Hardie Compound Base Coat 4kg Tub.

Please let me know fi you have any questions.

Mitchell

[tom138]

Hey @MitchellMc, thanks for the info. But they seem to install an aluminium angle into corners first before they put the sheets up, which seems to be what the JH installation guide also suggests. Thanks, Tom

[tom138]

Sorry I re-read your answer and I think I understand. You’re saying that the internal perforated angle should not be used but what I purchased is suitable for this application?

[tom138]

Just to clarify this is the section I was referring to:

 

[MitchellMc]

Hi @tom138,

I've just contacted the James Hardie technical team to ensure I've provided the most up-to-date information.

Initially, scrap my comment about setting the front side. That's only for when you are painting the sheets. If you are tiling, you just seal that joint on the front side with a polyurethane like Sikaflex 11FC. 

So, for the back side, you need to use a non-ferrous angle, and the plasterer's one you have is ferrous. You'll need to use an aluminium angle. Given that you have quite a large gap between your studs, grab an angle large enough to transfer over sufficiently onto the studs and be fixed off. It also wouldn't be a bad idea, if there is room, to add some timber blocks on the other side of the timber frame to join those studs in the corner together physically.

Please let me know if you have any questions.

Mitchell

[tom138]

Thanks @MitchellMc !