Paint not going on the same colour.

[john306]

Hi, I've just had a new solid roof fitted on our conservatory. To replace the old polycarb one.
The new one inside was plaster boarded and plastered.
I left it 3 days and it had all dried out as plasterers recommended.
I mist coated it 50/50 paint water, then 3 coats of Matt white emulsion.
The roof has 3 flat areas raising to the top.
2 of these areas have taken paint perfect.
The 3rd is quite a bit darker, much like a shadow effect.
It was all done at the same time with the same paint and roller.
The panel with the problem is the whole of the one section exactly.
I did take photos but they haven't come out well so will try again tomorrow.
Any advice appreciated.
Thank you

 

[john306]

 

[john306]

I've even tried colouring over a small section with some magnolia paint I had, then over painted with white and it's still exactly the same.

 

[opps]

It's hard to tell form the picture but it does look like a shadow. How does it look when the sun goes down?

 

[john306]

Hi, it's exactly the same.
Does look like a

shadow but definately not.
It's hard to focus taking a picture too close

 

[john306]

Another view

 

[opps]

Perhaps the plaster on that section is slightly thicker and hadn't dried as much. I can only suggest that you leave it for a couple of weeks and see what happens. Now that it has been painted, drying time will be extended.

 

[john306]

Hi, the majority of the painting was done 2 weeks ago after leaving plaster to dry.
Admittedly it's been cold and damp weather almost ever since so maybe you're on to something, so I'll wait a while longer.
Thank you

 

[JohnD]

Ceilings usually dry out fast.

Is that the shaded side?

How is it insulated?

How is the room ventilated?

Is there a source of humidity, such as wet washing?

 

[john306]

Not shaded side no.

Its a complete solid roof system, 1 very thick grey slab of it initially, then 60mm foil backed insulation before plaster board went on.

Ventilated by 4 opening windows.

Nothing to cause any damp no.

Funny it's only in the 1 section when the other 2 sections joined to it are perfect.

 

[sparkwright]

Could something to do with the plaster drying out.

As it's all of that section, I wonder if it's something like that section has had two layers pf plasterboard (for whatever reason) and it's making the plaster take longer to dry out fully?

 

[john306]

Could something to do with the plaster drying out.

As it's all of that section, I wonder if it's something like that section has had two layers pf plasterboard (for whatever reason) and it's making the plaster take longer to dry out fully?

Thanks.
Hopefully that's it.
But the other 2 sections painted at the same time dried out perfectly by the following day.
This problem section had been drying now 2 weeks.
But as someone else replied I'll wait it out and fingers crossed or I'm stuffed.

 

[sparkwright]

That's it then - the plaster wasn't dry enough.

See how it goes.

 

[john306]

That's it then - the plaster wasn't dry enough.

See how it goes.

Could well be.
I left it 3 days after plastering and until it had dried out and pink coloured as per plasterers instructions.
Just funny how is only that one section and not patches here and there.

Do you think it will go same colour as other sections if it is indeed not dried yet, or should it need another coat of emulsion?

 

[sparkwright]

Thanks.
Hopefully that's it.
But the other 2 sections painted at the same time dried out perfectly by the following day.
This problem section had been drying now 2 weeks.
But as someone else replied I'll wait it out and fingers crossed or I'm stuffed.

Sorry, may have mis-read this.

What's been drying for 2 week?
The problem section plaster?
Or the problem section paint?