Damp issue on microcement shower

CeeVee

Well-Known Member
#1
Did a shower in micro and I gave it a coat of clear matte. Then when the guy has a shower these damp patches appear. I said it would need another coat of clear but I was working for the bathroom fitter so he gave it a coat as I was busy.
This is still happening when he showers....why?
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zolco

Private Member
#2
Can you sand it back and re apply the epoxy? If it's cold when you apply epoxy it can bubble, you can try eliminate the bubbles with a plumbers torch without burning the epoxy if that's the case
 

CeeVee

Well-Known Member
#3
Can you sand it back and re apply the epoxy? If it's cold when you apply epoxy it can bubble, you can try eliminate the bubbles with a plumbers torch without burning the epoxy if that's the case
Can I sand part of the wall and recoat with epoxy?
 

zolco

Private Member
#4
Can I sand part of the wall and recoat with epoxy?
No idea tbh, I'm only just guessing but can't see why not. I never done microcement, tried some epoxy flooring and that gets sanded back to get the orange peel effect out
 

plas1

Well-Known Member
#5
Do they dry mate?As in if he doesn't use shower will they go away until used again?
 

plas1

Well-Known Member
#8
sounds to me you've got very small open pours.I don't know the system you've used but I had a problem a few years back with same problem.If you inbox me your number I'll give you a call later.
 

RobJack

Well-Known Member
#12
It does look like water ingress. Its absorbing moisture. I have used that product before but changed to another brand so I've not used it for a while. I cant remember ever getting this problem though. I would say the sealer isnt doing its job correctly. If its a 2 part sealer then it may not have been mixed enough or have the correct ratios, or there may not be enough sealer on there in the first place. Id let it dry out fully and re seal it again. Do it yourself though as the other guy could be doing it wrong. Was there a penatrative sealer first before any top sealers?
Have you spoke to where you bought it from. Im assuming It's applecart
 

CeeVee

Well-Known Member
#13
It does look like water ingress. Its absorbing moisture. I have used that product before but changed to another brand so I've not used it for a while. I cant remember ever getting this problem though. I would say the sealer isnt doing its job correctly. If its a 2 part sealer then it may not have been mixed enough or have the correct ratios, or there may not be enough sealer on there in the first place. Id let it dry out fully and re seal it again. Do it yourself though as the other guy could be doing it wrong. Was there a penatrative sealer first before any top sealers?
Have you spoke to where you bought it from. Im assuming It's applecart
Thanks mate.
No penetrative sealer only the two part sealer supplied and taught on the course.
Taking your view and what I now know about the customer I think like you say theres something wrong with the sealer and/or application of sealer.

I think i missed some when giving it the first coat.
After he's put on the second coat I think the customer has jumped straight in the shower and washed it off. Or he's put a second coat on incorrectly.
 
#21
Thanks mate.
No penetrative sealer only the two part sealer supplied and taught on the course.
Taking your view and what I now know about the customer I think like you say theres something wrong with the sealer and/or application of sealer.

I think i missed some when giving it the first coat.
After he's put on the second coat I think the customer has jumped straight in the shower and washed it off. Or he's put a second coat on incorrectly.
Hi CeeVee,
First of all dont pay to much attention on my English.
Second, is that sealer water based? If so, high level of moisture and direct water can form such marks.
I would try to dry the walls, sand it a little bit and then overcoat it with nonporous (solvent based) Pu sealer. Any epoxy wouldnt do because of poor adhesion over PU.

I experienced similar situation concerning floors. If you put anything with flat bottom on wet microcement floor (coated with water based pu sealer) captured moisture under that bottom goes back to microcement and makes dark marks. And they stay there mainly forever.

I hope you already solved it, but if not, maybe it would be usefull
 

CeeVee

Well-Known Member
#22
Hi CeeVee,
First of all dont pay to much attention on my English.
Second, is that sealer water based? If so, high level of moisture and direct water can form such marks.
I would try to dry the walls, sand it a little bit and then overcoat it with nonporous (solvent based) Pu sealer. Any epoxy wouldnt do because of poor adhesion over PU.

I experienced similar situation concerning floors. If you put anything with flat bottom on wet microcement floor (coated with water based pu sealer) captured moisture under that bottom goes back to microcement and makes dark marks. And they stay there mainly forever.

I hope you already solved it, but if not, maybe it would be usefull
Thats very useful to know cheers mate.
Worth staying away from water based sealers all together