Want to seek advice. I'd had leaking and termite issues previously which had damaged some of my internal paint. Its sorted now, and after a very long time finally decided to fix repaint walls and replace skirting to pvc.
Question, the leak had quite a damage as per pctures. It flake the paint and i had scrap whichever portion i managed to. Evwn the undercoat or sealer was also easily scrap out which leaves a thick layer between the ok portion and bad portion.
I will later try to sand the area between the ok and bad ones to leave as smooth as possible finish between those.
Question, to fill the gap between the ok part and bad part, what is best material? I experimented putty fill (liquid type) but its hard as it cant coat thick layer. Would a normal paste putty filler does the job or there are better options?
And assuming if i manage to fill with putty and sand it to level, would i need primer or sealer on the repair part? Iplan repaint the whole wall, would there be visible mark on the repaired portion?

Thanks for the advice. The cement to water portion use 1 cement :0.5 water ? In event i didnt do a good job on plastering the cement, can the cement be sanded via sanding machine probably with mid grit paper? Since i not very confident on my plastering skill with cement

Yup, the water seeping is sorted as i did foam injection and t200 on outer layer a while back. Speaking of patching the wall, i went to those local hw shop, they advised to use stopping compound vs cement as it will be easier and smoother, i bought both to test on different areas see which will be easier to work with.

On a side note i havt started though coz i have another problem to solve before working on this, have yet to sand it as well. Figuring a way to airtight my wardrobe sliding doors so no dust can go in when i do sanding.

So i patched my wall using stopping compound as cement is a bit hard to work with, actually both also hard to work with, stopping compound in my bucket dries and hardened before i complete.
Now that i patched, put on a layer of undercoat paint, only to noticed there is hollow sound when knock on patch area, is this normal? It happends to the bigger patch area the hollownsound is like a very hard layer not sticking, the smallet one near the window doesn't have a less audible hollow sound.
Is this normal for a patched wall, or i need redo the patching? Before i eventually paint it


This post has been edited by dixonleong: Aug 1 2020, 01:02 PM

I think so, because the hollow area is near joint of plastered patch and good area, likely i was trying to smooth out that area didnt put much force and density there. I think I'll wait a week more to see if the hollow worsen or spread to other partt, else just paint coat it. Too much hassle and dust to redo especially sanding part..... Fell sick for 2 days after sanding despite wore mask and goggles

Lol, double 3 ply normal mask only.

I had another room's wall have some condensation issue causing paint to shrink and flake. After investigating the area, its where the internal aircond drain pipe is, suspect the developers never insulate or didnt insulate the pipes properly.
I'm not intending to break the walls and insulate the pipes properly, as the moisture or "sweat" from the pipes wouldnt be that massive. I'm looking to scrap the current paint, undercoat the walls with some sort of waterproof paint before repainting it.
What sort of undercoat waterproof paint is recommended and that comes in 1 liter pack, cause it's a very small area ?