How to fix darker patches?

Feel free to laugh at my stupidity

I tried to fix some patches on my walls using the same paint color and type (vinyl matt emulsion) but the areas became darker. So I decided to paint the entire wall again to fix this but the dark streak/patch is still there.

I've tried:

-Painting patch with roller
-Painting patch with brush
-Painting entire wall
-Leaving wall to dry for days

Still the same problem



How do I fix it? Going crazy here.

is it new plaster?

Is it damp? Stand back and photograph the whole wall.

Is there a source of water, such as a bathroom, kitchen, wet washing or leaking gutter nearby?

JohnD said:

is it new plaster?

Is it damp? Stand back and photograph the whole wall.

Is there a source of water, such as a bathroom, kitchen, wet washing or leaking gutter nearby?

Click to expand...

Hi,

The building is brand new and the walls were all painted by the contractors before I moved in. It's difficult to get a picture of the entire wall because it's a narrow hallway. The strong light above also distorts the colors a bit.

There is a boiler to the left of the blue door but it is enclosed within its own room.

My apartment is in the corner basement of the building.



I can't feel any dampness with my fingers but I guess that's not a good test. Would hiring a dehumidifier help?

try taping a piece of clear plastic tightly to the wall. If beads of moisture form under it, the wall is wet.

From the shape, I suspect a leak in the room above.

But do any pipes run into the boiler room from there?

Was the patch as bad as it is now before you tried patching it up? Using the same paint doesn't necessarily mean you will get an unnoticeable patch up - paint fades/darkens over time and so, occasionally, applying fresh paint to just one area can make things look worse. You can also make the patch worse if you have used a different application method, i.e., roller instead of brush or vice versa, different type of roller, etc., because the texture will be different to the rest of the wall (this may be more likely if the building is brand new and the room was only recently painted). If the area has a different texture, you may get better results by sanding the area smoother and then repainting the entire wall.
Of course, if the patch was already as bad as it is now, you could well have another issue such as moisture which has already been alluded to.

Also, is the area a joint in the drywall that has been taped and mudded, as this could also be the source of the problem? I ask this assuming you are actually in the US, as suggested by your profile location.