When a small area of a texture ceiling is damaged, say a 1 foot by 1 foot patch in a 1000 square foot room, you have the option to spray just the patch and blend it in to the existing texture or scrape off all texture connected to the damaged area and spray the entire room again.
Should I try patching the small area of damaged ceiling texture or scrape and respray the entire room? Things to consider:
The age of the damaged texture.
Older ceilings can discolor over time and a fresh white texture patch repair may stick out and be an eye sore.
Has the existing texture ceiling ever been painted with a latex or oil based paint?
It is quite common for older texture ceilings to be painted to freshen up the color or block stains. Painted ceiling texture has a different color and slightly different appearance than fresh new texture.
Water based paints to not pose a problem when attempting to blend a patch but oil based paints make it almost impossible to transition seamlessly from old to new texture. I have done it many times though when scraping and respraying the whole area is not an option and can look good but is not the best solution.
If the new texture patches color does not match the color of the existing texture, the whole room can be repainted or if the existing texture was painted prior, an attempt to just paint over the new patch with the same paint (after it has dried for 24 hours) is worth a try and has worked in the past.
Where in the ceiling is the texture repair located?
A repair in the middle of a room is not as easy to repair as a patch in the angle against the wall.
Is the rest of the rooms texture finish still properly bonded to the drywall?
This is a common issue in moisture related repairs (mostly shower areas).
I will remove the obvious damaged texture and then test the bond of the closest surrounding area by tapping my fingers around to make sure nothing else is loose. If I feel any movement then I take all of the texture off, prime the drywall and spray the entire room again.