Plastering / Skim Coat on Cement Board .. Information / Help / Advice Appreciated

Good Afternoon Folks,

Forgive me if this is a repeat subject, and please feel free to point me towards any threads on the same topic;

Plastering / Skim Coating onto Cement Board, appears I am running into a brick wall headache over what needs to be done or used.

So anyone who has been through this, with successful results, your opinion / advice would be greatly appreciated.

1 - Walls are Cement Board ( Bathroom and Half Kitchen ) - Rough side out.

2 - Plasterers are very reluctant to touch it as they are not sure what they need to do, as rendering onto brick / breeze blocks seems to be their stock in trade around here, which is fine.

3 - Materials - Products, what is required in order for this to work as I believe trying to just skim it will fail as the cement board removes the moisture and does not provide a secure bond. - Will be sourcing from Global / Thai Watsadu as my nearest, however, open to buying from online suppliers if I cannot get instore.

Any thoughts at this point would be greatly appreciated.

Hi,
If it's in the bathroom and kitchen, wouldn't you be putting tiles on it?
If you want a plaster board finish, I would suggest screwing wet area plaster board to it.

Cement board forms a durable, stable base for tile, and it has no organic materials (unlike drywall, greenboard, or plywood) so it is not prone to mold, rot, shrinkage, or decomposition due to moisture. Ceramic tile laid over cement board is one of the most durable floor or wall surfaces you can install.25 Feb 2020

From a home improvement site. You need to apply a special primer. This is followed with with an adhesive coat. A fiberglass mesh material is then applied on top of the glue. Then the render is applied which I notice is silicone based. The system comes as a kit to cover 25 or 50 m2. I would doubt that a similar product would be available in Thailand but you never know.

As you can see from the number of replies, nobody has a clue. A picture would be helpful. Why is skimming over cement board any different than skimming over brick or block which I know the Thai men are very good at. The skimming the Thai men do, they make it look easy, but I have tried it, its damned hard.

Thanks for the replies, decided to do the African thing .. Make a Plan :rolleyes: Bathroom is now fully tiled, Kitchen will be as well, the remaining cement board walls were painted in a watered down PVA mix and left to dry. Then .. a couple of bags of white skim plaster mixed well with cheap white paint and rollered on as a base coat. Covers up the joints well, that's now been up for 3 weeks and so far no shrinking or cracking or movement.

OK so it looks like a very light artex, but i'll live with the trade off of not having the walls covered. If we get the final colour right, it should actually look OK.

Rather amusing watching my guys roll their eyes and mutter that I had lost the plot when they saw the mixing taking place, I did notice though, 3 days later when the trail areas had dried, they were in there taking photos of it and animatedly discussing how easy it was to do and the end result was better than they thought :smileylaughing: