Neutral cure Silicon & Mapei tanking

[J_c]

I'm installing some acrylic shower panels onto Aquapanel. Ideally I'd like to seal the shower tray to the wall with Classi seal or similar then tank over before installing panels, for the best possible seal. The glossy acrylic panels I'm putting in (lustrolite) need a neutral cure Silicon sealant, but I'm not sure if it will bond with a surface treated with Mapegum, or if there might be some reaction that causes a problem. Neither Mapei nor Lustrolite have been able to tell me for sure -- does anyone here know?

The shower panel manufacturers have said I don't need to bother tanking and that it's sufficient to use No More Leaks round the shower tray and then install the panels directly onto the Aquapanel (with plastic trim at the internal corner and edges). Second question then -- is that sufficient protection against leaks? I'd be happy to take their advice but most threads I've read here have advised tanking in similar circumstances, and I'd like to do every possible thing to avoid any leaks in future.

Cheers thanks in advance for any advice -- Jamie

 

[Waluigi]

Lustrolite is a completely waterproof barrier so nothing should need tanking, Aquapanel shouldn’t be necessary either as there’s no weight in the 4mm panels.

The classi seal isn’t a bad idea though.

Answering you question about the Silicon, yes it would bond fine with Mapegum. Provided the sealant is applied to the Mapegum and not the Mapegum applied to dry sealant.

 

[J_c]

That's really useful mate, thank you so much. It's great not to have to tank, and I've got some classi seal ready.

At the joins between the boards there's a slight unevenness -- just a couple of mm despite my best efforts as I was setting them up. Will that be a problem for the lustrolite? It's not huge -- not more than 2mm -- but it's there.

Do you know what best practice is in this case?

 

[Boggs]

The substrate joints need sealing with Silicon or tanking liquid and also behind where the Lustrolite panels meet.

The 4mm joint where the panels meet needs filling with Silicon which will help disguise the difference.

 

[J_c]

Cheers Boggs. Since I used aquapanel (I'd already bought it, but I get Waluigi's point about lustrolite being really light) the joints are filled with knauf adhesive. I called them up for advice, and they said to butt them up directly against each other after applying the adhesive to one edge. I did this then fixed them mechanically, then sanded the adhesive down after it dried to try and get the seams as flat as possible. They're still a little wonky.

The uneven joint in the substrate will actually fall behind a panel of lustrolite -- it's at the point where one cement board sits on top of another (don't know why they're not perfectly flush, the edges of both are fixed to the same noggin). Maybe I'm worrying too much! -- it's a very small overlap and I guess I'll hope the rigidity of the acrylic will mean the shower panel sits over it no problem.

 

[Boggs]

You will be fine, I wrongly assumed the lip was on the finished panels.

Although if you already have the tanking liquid I would tank behind anywhere that the lustrolite boards will meet.

All the best with your install.

 

[Nic_P74]

Cheers Boggs. Since I used aquapanel (I'd already bought it, but I get Waluigi's point about lustrolite being really light) the joints are filled with knauf adhesive. I called them up for advice, and they said to butt them up directly against each other after applying the adhesive to one edge. I did this then fixed them mechanically, then sanded the adhesive down after it dried to try and get the seams as flat as possible. They're still a little wonky.

The uneven joint in the substrate will actually fall behind a panel of lustrolite -- it's at the point where one cement board sits on top of another (don't know why they're not perfectly flush, the edges of both are fixed to the same noggin). Maybe I'm worrying too much! -- it's a very small overlap and I guess I'll hope the rigidity of the acrylic will mean the shower panel sits over it no problem.

That usually happens when the noggin has a slight twist on it. Only needs to be 1mm which will kick your board out 2mm by the time it meets in the middle of the noggin.