Caulking Shower

[Joey115]

Awhile back I had a company come to caulk the joints and bottom on my shower. The shower had grout instead of caulking where it meets the shower tray and in the corners. The company was to remove it and apply caulk. Instead they caulked over the grout. Shortly after it started to crack at the shower tray and mold started to form between the grout and the new caulk.
After a lot of back and forth and frustration, I decided to take over the project and re-do the job. The company told me that they only were to scape the old grout past the face of the tile so the caulk had something to sit on. They didn't even do this, which is partly why I think it cracked. Also they said there must have been movement with the shower tray, which is blamed on construction, not the way it was applied. I had asked him why they did not weigh down the shower tray, as I was told by many people after the job was done, that this was the normal way to apply caulk. The company said it was not needed. I think this may have also contributed to the cracking.
They also explained that the tray must have been pitched, to cause water to get behind the caulk and cause mold. I was suggesting that if they applied it over old grout, that mold could possibly grow between the grout and new caulk- especially if it wasn't bleached or cleaned prior to application. They insisted it was the construction
Aside from all that, I want to make sure I apply the new caulk correctly. I wound up removing all the grout in the corners and where it meets the tray. Was this a mistake (I know I should have asked this prior to doing it)? Will the caulk be able to sit if the grout was fully removed?
Also, I am planning on weighing the tray down even though it was suggested it was not needed. I would rather play it safe than have cracking again. Unless I am mistaken, I don't see how weighing it down could pose an issue?
Thanks in advance for the advice.

 

[HERTS P&D]

When you stand in the shower does the gap get bigger between the shower tray and the wall?

Andy

 

[xeres]

Hi there

The tip here is to be absolutely sure you have removed any old caulking and grout (although by caulk, we should be referring to Silicon - will use this reference henceforth). Any loose bits will obviously cause issues of adherence.

The second is as you state, weigh it down as much as possible and silicon seal it with considerable weight in it. I used 3x 10L tubs of paint, sat on them and siliconed around. There may always be a small amount of movement regardless of flooring (i.e. Wooden floors flex ever so slightly). Be careful though, if you can see visible movement of the shower tray when in it, you need to check the stands and that it is seated squarely. You should not see any visible movement and have to scrutinise even with all the weigh applied. Also, don't remove the weight until the silicon has set (24 hours minimum).

Third, use good silicon - Down Corning is the dogs and is all I would use. Silicon is a nightmare to scrape out and reapply and particularly so with silicon not sticking to silicon such that you have to be absolutely sure you got everything out. Do it once, do it right - use Dow Corning.

As regards the tray 'pitching' and not draining correctly, it is easy to test this. Grab your spirit level and check each axis: Up, across and diagonally both ways. It should be level to work correctly. Do you find that pools of water accumulate in certain areas? It is not necessarily a disaster if it does, just put a squeegee in there and be sure to squeegee away after every use. This is good practice anyway and will ensure your shower stays in good nick far longer than anything else.

Hope that helps.

 

[xeres]

Also, be generous with your application of silicon! A good thick bead and squirt it right up and under, the bigger the better!

 

[Joey115]

Thanks for the responses. I will have to see with a level. I don't think there is a pitch problem. I think the issue was more with the job they did- it didn't make any sense to me that they would put caulk over the grout without removing it first. I think that is why there was mold behind it. I never had an issue with the water puddling anywhere. I also never saw any visible movement with the tray. Since it wasn't weighed down, I figured that's why I was getting hairline cracks (that and just putting it over the grout).

 

[xeres]

Grout is brittle and should never have been used i the first place. You are right to assume that they should have removed it.