Painting a kitchen ceiling - Preparation Advice required

nero33

Had a water damaged ceiling that I'll be ready to paint soon once I've applied a bit of stain block paint.

Had to remove a fair bit of the old paint.



If I just do some undercoat and a couple of coats of kitchen paint, it'll still be uneven where I took the old paint off.

How to I prepare this surface and the rough paint edges so that it looks fairly level when repainted?

Thanks

ArbitraryRandom

Following as I'd like similar advice re damaged silk paint in a bathroom... 

ThisIsWeird

Hi Nero and Arb.

Just done this very job a couple of weeks ago following a leak in the upstairs loo, albeit on a much smaller ceiling area. As you've sussed, your main issue is going to be to match in the paint edge.

Make sure the remaining paint is well secured. Scrape off any loose bits of plaster. Clean - scrub - off as much stain marks as you can - what you have there looks generally clean, but there are a couple of black areas - see if you can clean these up a bit. Give all the exposed plaster a light sanding - this will clean it up more, and also give a good surface 'key'. 

Also lightly sand the surrounding paint to ensure there's no edges sticking up higher, but especially concentrate on any hairline cracks that may be on them - I can see one. Flatten these cracks to ensure they have no raised or loose edges - just ensure they are flush with the rest of the paint. Then hoover with a brush attachment the whole surface, especially along any cracks - you want these cracks cleaned out from dust and debris; you want them as clear and open as possible.

Ok, my current go-to product is SBR. This is a multipurpose liquid which is a building adhesive and waterproof sealer and primer. Think of it as super-PVA and you won't go far wrong... I have used it - this very day, actually - to try and sort some recurring cracks in the ceiling in our new extension, as well as a few weeks ago to sort (seemingly successfully) the cracks and water marks in the dining room ceiling from that leak.

This stuff will seal and bind together any loose bits and cracks, and also successfully stain-block. It is water-based, and nice to use. Excess wipes away with a damp cloth. When dry, it'll take emulsion paint beautifully.

You can use a mini roller for ease of application, or a brush - tho' it'll likely trickle down your arm, and you'll spend the rest of the day peeling the dried stuff off. That's a bonus.

The 'secret' it to keep applying it until no more is sucked in. On the main plaster surfaces, this is not an issue - one coat will do it. But keep an eye on any cracks and damage, and keep 'loading' these bits with SBR, looking at it closely to see if it's being drawn in by capillary action. Keep on dabbing these parts until it sucks no more - the stuff will glue and bond all these cracks together. When no more is drawn in, then brush/roll away the excess, and use a damp cloth to remove any on the surrounding painted surface.

NB - get the SBR right up to the remaining paint edges - it'll help to bind them down.

Unlike PVA, there will be no issue if you do get it on the painted surface - fresh paint will go straight on to it. But I try to avoid this in case it leaves a raised step that may show through the paint. You do not need to wipe away all the SBR from the painted surfaces, but give it enough of a wipe to make the layer feather.

Allow to fully dry.

Now comes the painful bit. There's no two ways about this - you are going to have to add a thin layer of fine-surface filler over the missing areas. If you have a large plasterer's trowel, you'll likely manage this in one go. With a filling knife - even a 3"-er - it'll likely have to be done in stages, getting it as best you can, sanding it down, and then filling in any gaps...

On this issue, there are seemingly lost of nice 'easy-plaster' products now available, but I haven't used any so cannot comment. I usually resort to standard filler, and know that I'll likely have to sand-and-fill at least a couple of times to get it near-perfect.

Some points, tho' - use the remaining painted surface edges as your level guide. So, apply a little filler to the bare plaster inside the painted surround, and bring whatever trowel or knife you have down firmly on the painted surface, with only an overlap of the blade going on to the bare area - sweep around the painted are, levelling the filler over the bare plaster, so it matches the level. Don't allow too much filler to remain on the painted surfaces, as it'll just mean more sanding.

Continue over the whole bare areas as best you can. If you are new to plastering, the finish will likely disappoint you, but that will be sorted when it dries.

Get a nice hand-held sanding block of a good size - something like this: https://www.screwfix.com/p/aluminium-hand-sander-240mm-x-84mm/811rt

Use it with ~120 to 180 grit paper, and again use the painted surface as your guide - work from the painted surround areas on to the filled areas - blend them in!

Wipe clean using a damp cloth. If there are any obvious holidays, then add another skim - but this time it should be a lot less (be ready to add a touch of water to the additional skims, if the existing plaster sucks the filler dry too much.)

Finally, when fully dry and as flat as you can get it, apply your first layer of emulsion paint, diluted ~10% with water. Once fully dry, you should be able to see how good the job it. Fill or sand some more if needed.

Then at least two full coats over the whole ceiling.

nero33

ThisIsWeird said:

Hi Nero and Arb.

Just done this very job a couple of weeks ago following a leak in the upstairs loo, albeit on a much smaller ceiling area. As you've sussed, your main issue is going to be to match in the paint edge.

Make sure the remaining paint is well secured. Scrape off any loose bits of plaster. Clean - scrub - off as much stain marks as you can - what you have there looks generally clean, but there are a couple of black areas - see if you can clean these up a bit. Give all the exposed plaster a light sanding - this will clean it up more, and also give a good surface 'key'. 

Also lightly sand the surrounding paint to ensure there's no edges sticking up higher, but especially concentrate on any hairline cracks that may be on them - I can see one. Flatten these cracks to ensure they have no raised or loose edges - just ensure they are flush with the rest of the paint. Then hoover with a brush attachment the whole surface, especially along any cracks - you want these cracks cleaned out from dust and debris; you want them as clear and open as possible.

Ok, my current go-to product is SBR. This is a multipurpose liquid which is a building adhesive and waterproof sealer and primer. Think of it as super-PVA and you won't go far wrong... I have used it - this very day, actually - to try and sort some recurring cracks in the ceiling in our new extension, as well as a few weeks ago to sort (seemingly successfully) the cracks and water marks in the dining room ceiling from that leak.

This stuff will seal and bind together any loose bits and cracks, and also successfully stain-block. It is water-based, and nice to use. Excess wipes away with a damp cloth. When dry, it'll take emulsion paint beautifully.

You can use a mini roller for ease of application, or a brush - tho' it'll likely trickle down your arm, and you'll spend the rest of the day peeling the dried stuff off. That's a bonus.

The 'secret' it to keep applying it until no more is sucked in. On the main plaster surfaces, this is not an issue - one coat will do it. But keep an eye on any cracks and damage, and keep 'loading' these bits with SBR, looking at it closely to see if it's being drawn in by capillary action. Keep on dabbing these parts until it sucks no more - the stuff will glue and bond all these cracks together. When no more is drawn in, then brush/roll away the excess, and use a damp cloth to remove any on the surrounding painted surface.

NB - get the SBR right up to the remaining paint edges - it'll help to bind them down.

Unlike PVA, there will be no issue if you do get it on the painted surface - fresh paint will go straight on to it. But I try to avoid this in case it leaves a raised step that may show through the paint. You do not need to wipe away all the SBR from the painted surfaces, but give it enough of a wipe to make the layer feather.

Allow to fully dry.

Now comes the painful bit. There's no two ways about this - you are going to have to add a thin layer of fine-surface filler over the missing areas. If you have a large plasterer's trowel, you'll likely manage this in one go. With a filling knife - even a 3"-er - it'll likely have to be done in stages, getting it as best you can, sanding it down, and then filling in any gaps...

On this issue, there are seemingly lost of nice 'easy-plaster' products now available, but I haven't used any so cannot comment. I usually resort to standard filler, and know that I'll likely have to sand-and-fill at least a couple of times to get it near-perfect.

Some points, tho' - use the remaining painted surface edges as your level guide. So, apply a little filler to the bare plaster inside the painted surround, and bring whatever trowel or knife you have down firmly on the painted surface, with only an overlap of the blade going on to the bare area - sweep around the painted are, levelling the filler over the bare plaster, so it matches the level. Don't allow too much filler to remain on the painted surfaces, as it'll just mean more sanding.

Continue over the whole bare areas as best you can. If you are new to plastering, the finish will likely disappoint you, but that will be sorted when it dries.

Get a nice hand-held sanding block of a good size - something like this: https://www.screwfix.com/p/aluminium-hand-sander-240mm-x-84mm/811rt

Use it with ~120 to 180 grit paper, and again use the painted surface as your guide - work from the painted surround areas on to the filled areas - blend them in!

Wipe clean using a damp cloth. If there are any obvious holidays, then add another skim - but this time it should be a lot less (be ready to add a touch of water to the additional skims, if the existing plaster sucks the filler dry too much.)

Finally, when fully dry and as flat as you can get it, apply your first layer of emulsion paint, diluted ~10% with water. Once fully dry, you should be able to see how good the job it. Fill or sand some more if needed.

Then at least two full coats over the whole ceiling.

That's a phenomenal answer!  Really appreciate it.

Just a couple of questions.

1. The SBR adhesive/bond - is this applied just where the paint meets the bare plaster or over the entire bare plaster area as shown? (excuse my doodles)!


2. You said "Now comes the painful bit. There's no two ways about this - you are going to have to add a thin layer of fine-surface filler over the missing areas"

Is this thin layer applied in the whole of the bare plaster area, as shown inthe shaded area (see another rubbish diagram)?



Many thanks

ThisIsWeird

Yes x 2.
Apply the SBR liberally over all the bare plaster - it'll adhere any loose bits together, seal any cracks to prevent them opening up, prime the surface ready for skimming or painting, and block in the stain. For that last point, if it looks as tho' the stain is coming through that first coat of SBR - you may see a yellowish-briwn tinge, then apply a second coat when the first is dry.
Yes, go right up to and over the existing paint edges so they are sealed. Don't worry about go on to the old paint - just make sure everything is well coated - but do give these painted areas a quick wipe with a damp cloth to flatten and feather the SBR so it doesn't leave a physical ridge which might show through the new paint.
Pay attention to all the cracks - these are the plasterboard joints, and it's where the water came through. So, liberally apply SBR repeatedly to these, and observe closely - you want it to be sucked right in, so keep feeding it until it stops. It should bind and seal these joints, hugely helping them from reopening with temp changes.

With my current ceiling repair - final sanding and painting today, I hope! - I actually injected, with a needle and syringe, SBR right up the cracks. It was fab - droplets would first appear along the crack for a few inches either side, and then disappear as the SBR was soaked up into the p'board edges. I kept this going until no more was absorbed. Quick damp cloth wipe before it dried. When dry, the cracks were sealed fully across, ready for filling. Fingers crossed. The plasterer has already been back to sort the initial appearance of these cracks, and went for the usual method of mesh-taping  over, and feather-filling. Alas, didn't work. (Main issue was not his fault - I suspect it due to the roof construction providing too much movement in hot and cold weather.)
Anyway, good luck! You will get it perfectly acceptable! My recommendation of SBR is based on my own findings, and it just makes sense to me. 
You may wish to try one of these new magic skimming products - some are brush/roll on, and quick trowel after. Designed to allow DIYers to get decent results on poor wall surfaces. But, any general purpose filler should do. Look for 'easy-sand'. Read reviews - avoid any that say 'sets rock hard!'

nero33

ThisIsWeird said:

Yes x 2.
Apply the SBR liberally over all the bare plaster - it'll adhere any loose bits together, seal any cracks to prevent them opening up, prime the surface ready for skimming or painting, and block in the stain. For that last point, if it looks as tho' the stain is coming through that first coat of SBR - you may see a yellowish-briwn tinge, then apply a second coat when the first is dry.
Yes, go right up to and over the existing paint edges so they are sealed. Don't worry about go on to the old paint - just make sure everything is well coated - but do give these painted areas a quick wipe with a damp cloth to flatten and feather the SBR so it doesn't leave a physical ridge which might show through the new paint.
Pay attention to all the cracks - these are the plasterboard joints, and it's where the water came through. So, liberally apply SBR repeatedly to these, and observe closely - you want it to be sucked right in, so keep feeding it until it stops. It should bind and seal these joints, hugely helping them from reopening with temp changes.

With my current ceiling repair - final sanding and painting today, I hope! - I actually injected, with a needle and syringe, SBR right up the cracks. It was fab - droplets would first appear along the crack for a few inches either side, and then disappear as the SBR was soaked up into the p'board edges. I kept this going until no more was absorbed. Quick damp cloth wipe before it dried. When dry, the cracks were sealed fully across, ready for filling. Fingers crossed. The plasterer has already been back to sort the initial appearance of these cracks, and went for the usual method of mesh-taping  over, and feather-filling. Alas, didn't work. (Main issue was not his fault - I suspect it due to the roof construction providing too much movement in hot and cold weather.)
Anyway, good luck! You will get it perfectly acceptable! My recommendation of SBR is based on my own findings, and it just makes sense to me. 
You may wish to try one of these new magic skimming products - some are brush/roll on, and quick trowel after. Designed to allow DIYers to get decent results on poor wall surfaces. But, any general purpose filler should do. Look for 'easy-sand'. Read reviews - avoid any that say 'sets rock hard!'

Great, hopefully I'm good to go.  Just need the SBR.  When applying it, did you dilute the SBR with water.  If yes, in what ratio?  Thanks again

the_lunatic_is_in_my_head

Once you get to the the point of being ready to put the top coat on:

https://paintwell.co.uk/tikkurila-anti-reflex-white-2

Very good paint for ceilings, reflects very little light which hides imperfections. 

ThisIsWeird

nero33 said:

ThisIsWeird said:

Yes x 2.
Apply the SBR liberally over all the bare plaster - it'll adhere any loose bits together, seal any cracks to prevent them opening up, prime the surface ready for skimming or painting, and block in the stain. For that last point, if it looks as tho' the stain is coming through that first coat of SBR - you may see a yellowish-briwn tinge, then apply a second coat when the first is dry.
Yes, go right up to and over the existing paint edges so they are sealed. Don't worry about go on to the old paint - just make sure everything is well coated - but do give these painted areas a quick wipe with a damp cloth to flatten and feather the SBR so it doesn't leave a physical ridge which might show through the new paint.
Pay attention to all the cracks - these are the plasterboard joints, and it's where the water came through. So, liberally apply SBR repeatedly to these, and observe closely - you want it to be sucked right in, so keep feeding it until it stops. It should bind and seal these joints, hugely helping them from reopening with temp changes.

With my current ceiling repair - final sanding and painting today, I hope! - I actually injected, with a needle and syringe, SBR right up the cracks. It was fab - droplets would first appear along the crack for a few inches either side, and then disappear as the SBR was soaked up into the p'board edges. I kept this going until no more was absorbed. Quick damp cloth wipe before it dried. When dry, the cracks were sealed fully across, ready for filling. Fingers crossed. The plasterer has already been back to sort the initial appearance of these cracks, and went for the usual method of mesh-taping  over, and feather-filling. Alas, didn't work. (Main issue was not his fault - I suspect it due to the roof construction providing too much movement in hot and cold weather.)
Anyway, good luck! You will get it perfectly acceptable! My recommendation of SBR is based on my own findings, and it just makes sense to me. 
You may wish to try one of these new magic skimming products - some are brush/roll on, and quick trowel after. Designed to allow DIYers to get decent results on poor wall surfaces. But, any general purpose filler should do. Look for 'easy-sand'. Read reviews - avoid any that say 'sets rock hard!'

Great, hopefully I'm good to go.  Just need the SBR.  When applying it, did you dilute the SBR with water.  If yes, in what ratio?  Thanks again

Damn, good question...

I did, but only because I knew I had specific issues of reappearing cracks that I needed to sort, so I wanted the SBR to be as fluid as possible. I just added a 'splash' - a small amount, no more than 10%.

I'd only do so in your case if I thought that the plaster had been damaged within, and wanted the SBR to be drawn in by capillary that wee bit more.

You'll only need a small amount, but I think the smallest volume you can buy is 1 litre.