my new house (apartment not yet move in), but have finish renovate for almost 1 ~1.5 year...
the master room wall paint have been peel off,
plan to repaint but dont know need use what material,
primer? paint which type? price for primer /paint?
need how much primer/paint?

Same colour?

If same colour dont need primer, just paint another 2 coat should be fine.

If you want to remove the old paint first then maybe need primer, depends on you really

A thorough job would involve scrapping, then prime, finally finishing it with paint.

Typically contractors would save cost with maxilite as a primer but if it's for your own stay and you want it to last and have a good finish then I suppose a good primer is just as important.

A simple quick job would be to just scape away the peeling part then paint it over with existing paint to cover up

yes, going to scrap off the old paint as the paint that peel off, middle got powder which i dont know is what.

what brand/type of paint good?
primer?

procedure?

Previous painter used cheap primer or didnt use at all If you feel powdery use nippon hi bond wall sealer.

how to know i need how many liter of primer and paint?

Best if you could provide a photo of the paint peeling off as there are multiple possible reasons that your paint peeled off, it can be skim coat too powdery causing adhesion problem or simply an inferior sealer was used.
I would recommend you to identify the root cause of the problem first before your painting job. powdery surface would require special solvent based sealer/water based (with specific function that tackle particular problem) sealer to be applied before finishing coat. If it is due to improper coating system or inferior grade products, then simply scrap off the old paint films and apply 1 coat of sealer + 2 coats of finishing.

1 litre can cover roughly 6-7m2, do take note that you need to x2 the amount for finishing as there will be 2 coats of finishing in a proper painting system.

Basically previous paint the aka primer using the very cheap base cheaper than maxilite , not during renovation but during finish build paint from contractor

Scrap or not depends on you once you finishing just apply maxilite as a base coat doesn't matter which color you going to use

Then measure your height by using measuring tape then width
Example your height if 12 feet then wall are 10feet x3 then door not include just measure what available on there 4 feet now you have 34 feet So just 34x12 or 12x34 total 408 square feet paint needed

Each 5 litter paint for 2 layer enough for 350 square feet ask them when you buy the paint personal I using skk over than others brand

If you want diy just a roller+stick+paper tape , insert rollers handle into stick hard enough apply paper tape between the joint now tight enough

If you have extra water tong or paint tong pour 5 litter into tong mix
250ml water then mix it well or close the lid shake hard enough

Now submerged your roller into paint cover it all or back forward from your actions, shake the exceed paint inside the tong by spin left and right hard enough as long no dipping

Now apply into wall from up to bottom as long all surface covered then continue besides don't worry if the color or different as long covered

Once finish apply angle which roller cannot reach once all angles done long enough for you to apply again for wall if you feel still wet a fan will help or open window as long dry to touch but don't go scrap it

Once 2 ply base coat done let it fully dry apply color coat by tmr

So total are 4 coat , my shop take me 3 day's to finish painting for 1800 square feet

In painting, ur prep work (sand down the old paint since its peeling off) is more important than the actual painting if you want good results.
From experience its a waste of effort to paint over peeling surface as once the new paint rolls onto the old one, it gets wet from the new paint and peels off. Then it gets stuck all over the roller basically preventing a nice finish.

You can use a either hand sanding, or power tools e.g. sander, or use this [https://www.everythingcsmg.com/product/4-bosch-strip-disc-best-for-stripping-paint-and-rust-2608619287/] with an angle grinder.
Then you will need washi tape (easy to peel) or masking tape to tape off edges/window frames etc.
Get a roller handle with removable rollers + a couple more roller replacements.

Once u got it to bare cement coat u will need primer. Roughly 8m x 2.4m wall will be covered by 5L primer/sealer. Cheap one will do. Can go for no name one or use nippon sealer (5400) for interior.

The paint (finishing coat).. basically what you pay is what you get.
Cheap white paint is already diluted so add 3% water to it ok edi. Like matex, maxilite.

As for colour paint. Minimum standard I would go is for easy wash, cheaper paints you are cutting corner for the base and pigment (like super matex will come only in that range of fixed colours). But they will still work if you are on budget. Only dilute little bit 5% as over dilution will make it very runny and hard to control when painting. Paint is something that you really get what you pay for. Roughly 8m x 2.4m wall will be covered by 2 coats by 4.5L colour paint.

This post has been edited by ceo684: Jun 12 2020, 10:15 AM

as to repaint need to sanding the old paint,
and i currently no equipment to use,
better ask expert to take off and repaint the wall.

living area


master room


the door, bactery or ? look like cant wash off without scratch the paint....


1 more problem..
the electric fuse box inside the apartment,
this mean got terminate inside the wood beneath the fuse box?



Attached thumbnail(s)

That fine wood grain...very likely of termite infestation

how to solve it?
call electrician?

what if i dont scrap existing paint?

would it be really bad?

imagine if you wanna stick something to the wall but you don't replace the old existing tape with a new one, the adhesion would be a big problem right? If you don't do the foundation right the problem gonna comeback no matter what as the base coat is already loosely attached to the wall.

From what I see in your photos these are bubbling issue caused by moisture in some walls. check if the skim is powdery or not, if not then high chance that it is caused by moisture issue. Scrapping off old paints are not that difficult, just get a scrapper from the hardware store and scrap those old paint films off.

As for the door, those are molds growing on the surface. The humidity can be quite high in the house. I would suggest you to check your wall moisture level before your painting works. Is this an old house that left empty for some times?

New apartment but renovate fi ish for almost 1 year....
Not yet move in,
Plan early this year move in ut mco, so got postpone..

How to check moisture level?
Skim is?

Given the situation that the old paint is not sticking well to the wall..U will need 20L++ of paint just to cover one wall when other people just need under 5L.

Why?

Because the stuff in new paint that keeps that new paint liquid will just cause the old paint to release from the wall and where does this old paint stick to after release itself?

Your roller will get jammed up with all the old paint. Hence wasting time and money as you will need to clean the roller every single time

It will be OK to just repaint over if its relatively fresh and sticking strongly without bubbling or peeling.

The bubbling or peeling indicates too high water content in the wall (may be caused by painting too soon before letting the wall dry out after it has been built)

This post has been edited by ceo684: Jun 13 2020, 02:24 AM

Either the place not ventilated well (too wet and enclosed space with no ventilation for long time) or this might indicate a water pipe leaking.

Not ventilated sure, as empty for more that 1 year plus after renovate.

Pipe leaking nope as those are wall facing outside.

also, possible to just scrap off the affected area and repaint?
no need scrap whole wall?
also if can just scrap off affected area, still need use sealer for unaffected area?