Silicone joins at bottom of wall profiles - Tile Advice

[rboy_44]

Hi. Hope someone more knowledgeable than me can help. I am about to install a Merlyn Series 10 shower (sliding doors fitted in a tiled recess) and the instructions state that the inside of the vertical wall profiles need to be silicone sealed against the wall tiles (after the tray has been silicone sealed to the tiles all around the recess and left to dry). So this is fine, but what happens at the join at the bottom of the profile where the new vertical silicone meets the horizontal existing dry silicone around the tray? It’s my understanding that new silicone won’t bond well to existing dry silicone and if this is true then surely there will be a weak water ingress point at the bottom of the profile where the vertical and horizontal silicone meet? The instructions also state for the outside of the profiles to be silicone sealed at the bottom (going up only 50mm). Any help / clarification on this would really be appreciated. Thanks in advance.

 

[Qwerty]

Follow the instructions as they're written. It will be fine. The important silicone joint is the tray to tile 90° joint. The silicone on the frame is to prevent water egress past the enclosure

 

[rboy_44]

Follow the instructions as they're written. It will be fine. The important silicone joint is the tray to tile 90° joint. The silicone on the frame is to prevent water egress past the enclosure

Many thanks for this. So do I just smooth the new line of silicone (going down the profile) straight into the existing dry silicone on the tray to tile joint? Will this join not be susceptible to water ingress and let water get round the back of the profile?

 

[Qwerty]

Not if done properly. The outside of the enclosure frame/ glass are the only joints usually that require sealing. Very rarely is the inside required or advised

 

[rboy_44]

Not if done properly. The outside of the enclosure frame/ glass are the only joints usually that require sealing. Very rarely is the inside required or advised

Thanks but for the Merlyn series 10 it is required on the inside of the wall profile (https://merlynshowering.com/wp-cont...oor-fitting-instruction-MER-01-New-handle.pdf) so will it be a problem joining the new vertical silicone directly onto the existing silicone on the tray to tile joint?

 

[Qwerty]

As I said previously, not if done properly.

I am well aware about Merlyn stating that, which is why I said very rarely is it recommended or advised, infering that most other manufacturers don't do it and it is just fine. I have fitted countless Merlyn enclosures over the years and not often do I silicone inside. Usually only on heavily profiled tiles

 

[rboy_44]

As I said previously, not if done properly.

I am well aware about Merlyn stating that, which is why I said very rarely is it recommended or advised, infering that most other manufacturers don't do it and it is just fine. I have fitted countless Merlyn enclosures over the years and not often do I silicone inside. Usually only on heavily profiled tiles

Again thanks, but I’d like to follow the fitting instructions all the same.

 

[Chris N]

Again thanks, but I’d like to follow the fitting instructions all the same.

You usually only silicon the outside of a shower enclosure as any water/condensation can escape on the inside.

Just follow the instructions if you're scared!

 

[rboy_44]

Thanks Chris. If you read the full post you’ll see that I’m just trying to follow the installation instructions, but they state that the internal vertical profiles need to be siliconed - this means running new silicone onto the cured silicone on the horizontal tray to wall joint. But as you’ll know, new silicone doesn’t bond to cured silicone so am wary of ending up with weak points at the base of both wall profiles.

 

[Chris N]

Thanks Chris. If you read the full post you’ll see that I’m just trying to follow the installation instructions, but they state that the internal vertical profiles need to be siliconed - this means running new silicone onto the cured silicone on the horizontal tray to wall joint. But as you’ll know, new silicone doesn’t bond to cured silicone so am wary of ending up with weak points at the base of both wall profiles.

Will be fine...you're worrying unnecessarily.

 

[rboy_44]

Thanks but specifics would be more helpful, like do I follow the instructions or not? And if I do then do I just smooth the new silicone into the cured or butt it up against it? Or do I not follow the instructions and do something else?

https://merlynshowering.com/wp-cont...oor-fitting-instruction-MER-01-New-handle.pdf

Tried Merlyn and they’ve been next to useless. They suggested I do some research into how best to join new silicone to cured silicone and sent me a link to a specialist adhesive that I could try!

I’ve taken out the doors and removed all the existing silicone (as the original installer did a crap job with the install that resulted in leaks) and am about to reinstall so would quite like some certainty that I’m doing the right thing here.

Cheers.

 

[Qwerty]

As a professional wet room and bathroom installer and approved Novellini fitter I've given you my advice

 

[rboy_44]

Appreciate your advice but it was a bit vague / confusing to be fair. You initially said to just follow the instructions and it’ll be fine, then later you said that most of the time the profiles don’t need to be sealed internally (but sometimes they do).

 

[Qwerty]

No, I was referring to silicone onto silicone being fine (your original question), then added that internal sealant on the enclosure is not required as reiterated by another.

 

[Dumbo]

Ive got a merlyn 10 series . Tray sealed one day , screen up and sealed the next . Drier than a bone that has been put in a special bone drying machine .