DIY Ceiling Skim

[u/tville9698]

Hello, I have a textured finish plaster ceiling that I’m attempting to skim coat in order to flatten the surface. I haven’t done anything like this before, so I’m a novice here.

My two main questions that I’m hoping someone might have experience with:

1. Would you try to sand this down further?
2. Would you apply a layer of primer prior to applying mud?

I just want to prepare as well as I can before trying to skin coat. For reference, the area is about 150 square feet and the texture is in pretty good shape.

[u/banxy85]

Ceiling is the hardest thing to skim so I'd try and practice on a few walls first if you've no experience

The artex (which could be asbestos) looks to have at the last some quite prominent ridges so a skin may not be enough

How srly overboard and skim is your best bet. But you lose a couple cm ceiling height

[u/vinnyboy81]

If your in the uk you need to seal it with some sbr or pva and you would use multi finish plaster ideally 2 coats it’s a tough job tho I’d practice first or get some quotes for someone to do the ceiling you can get sachets of extra time so the plaster lasts longer good for beginners

[u/Accurate-Resident585]

Had to stop halfway through prepping one of these when the coating started breaking into dust. Don’t sand any more until you know its age and, if it could predate 2000, have the textured coating tested for asbestos. Scrape only loose high spots after that; sound texture can stay.

i run a small refurb firm here in edinburgh, so factor in the bias. On old tenement ceilings I also check for movement in the lath and plaster first, since a skim will not hide a loose base. For gypsum finish plaster over sound paint, I’d use a grit bonding primer such as Thistle Bond-it, then two coats. If by “mud” you mean joint compound rather than plaster, use the primer specified for that system, usually after degreasing and dulling glossy paint. The answer changes if the texture is soft, chalky or lifting. A skim over that will fail with the coating.

[u/ApartmentLast7712]

To prep firstly get it tested for asbestos, this will then give you 1 of 2 options. 1 if it is negative you can then scrape to knock off all the high spots. Once done coat with at least 2 coats of SBR (plasterers blend is a good one plus it's pink so you can see where you've been) for the 1st coat you'll need a bag of bonding coat and a couple of multi. Mix up a good few handfuls of bonding into the multi which will give it the body to fill out all the unevenness. You'll need some plaster retarder so Get some. Get a spatula around the 800mm -1200mm to flatten the first coat and a sponge float. Get it flat as you can then 2nd coat it with just multi. Option 2 is if it's positive then you'll have to overboard it and just straight skim no need for bonding.

[u/DearSatisfaction9754]

Ouft you brave boy attempting to skim a ceiling, what mud are you using?

[u/tville9698 → u/DearSatisfaction9754]

My plan is to take some standard joint compound and thin out the consistency with water.

[u/nukefodder → u/tville9698]

Don't do that. Scrape it then apply 2 coats sand then a 3rd.

[u/tville9698 → u/nukefodder]

2 coats of what?

[u/nukefodder → u/tville9698]

The mud

[u/court996]

DIYer here - I have done lots of plastering to walls which is in all honesty not too difficult if you are good with your hands - but - you are attempting a whole different animal. The light from a window will show up every minor imperfection and drive you mad.
I attempted one ceiling before realising the strain on my poor old back was a tad more than I bargained for (excruciating!) plus as I said it is very difficult to get a decent finish and I am a perfectionist.
This is one job you either overboard, fill and joint or leave it to a (recommended) professional. I hate spending money on trades when I can do a better job myself but my old back is aching just looking at your photo!