I have installed plasterboard on the ceiling, applied tape in the joints, and plastered and sanded to no end.
But I can't get it smooth.
I tried with grazing light and every single joint is visible. I'm considering if I've plastered too much so that there are almost small "hills."
Do you have any tips on how I can save this?
It's harder than you think to plaster nicely. In my own early attempts, I also used too much plaster. I've learned to plaster several times thinly with sanding in between. Have you painted or how do you know the final result? Then matte colors are forgiving. If you use a shinier paint, with grazing light, you'll never be satisfied.
Then maybe you're being too critical; it's common with DIY jobs.
The principle of filling is to fill the areas that are low. Use a really long putty knife. You sand down what stands out and fill in what is low. As a happy amateur, you should expect maybe 10 rounds if you want to get it perfect. Use a carpenter's pencil and draw light lines to really see the valleys.
You should use a putty knife that is at least 400mm wide, preferably 500. Then you first apply coarse putty as it does not shrink as much.
First, apply putty to the recessed edges with tape.
Then you apply putty at least two, probably three times, spreading the putty 40-50cm on each side of the recess. When you remove the putty, avoid applying pressure in the middle of the putty knife, instead focus more on the edges - this is actually the tricky part to master.
When sanding, you should only sand lightly with a few strokes, otherwise it takes too much off and you will need to apply putty once more.
The principle for filling is that you should fill the areas that are low. Use a really long filling knife. You sand down what sticks up, fill in what's low. As a happy amateur, you should expect maybe 10 rounds if you want to get it perfect. Use the carpenter's pencil to draw faint lines to really see the valleys.
Thanks for the good answer!
When you apply a lot of filling, isn't there an increased risk of it cracking at the joints when the house moves?
When applying a lot of filler, isn't there then an increased risk of cracking at the joints when the house moves?
Gypsum is inherently a dead material without movement provided you have framed and screwed correctly. What you need to fill are joints and screw holes which result in a given level. It can never be too little or too much. It can only be the right amount.
David.B. said:
