Paint lifting off window frame (interior)

[allthebuttons]

We moved into a house a year ago with a lovely 100-year-old bay window. The paint on it was a few years old but otherwise it seemed in good condition. We had decorators in right away who, amongst other things, painted the window.

Last night I noticed that substantial cracks have appeared in the the interior of the window. These cracks are not just in the one-year-old paint - on larger cracks you can see that the paint has lifted right from the wood.

My best guesses for the cause are either that the wood got wet (the exterior paint is a bit cracked although there’s no obvious evidence of wetness or rot) or that it was something to do with the recent humidity/heat (although this room doesn’t get hugely hot).

I’ve attached 3 photos – can anyone shed some light on what has caused this, and what I should do about it?

Thanks!

 

[KenGMac]

allthebuttons, good evening.

There is a possibility that the "New paint" has been applied over a very old dark brown / black stain or Shellac original finish?

Modern paint at times does not like being applied to old coating materials.

Have you any idea at all as to what the coating system was applied originally?

if possible in a very discreet position, remove a small area ans see what the original coating was, as above, suggest you google Shellac??

Ken

 

[allthebuttons]

Hi Ken,

The window was already painted white, as far as I know with ordinary solvent-based paint. We just got the decorators to give it a new coat with Duluxe Satinwood. It’s 100 years old so I don’t know how it had been painted in years gone by, but every house on the road has white windows so I assume it was that way from the beginning.

Where it’s cracked it only looks like white paint (can’t see any dark layers). The paint has come away from the wood “as one” – it’s not just the new paint.

 

[KenGMac]

allthebuttons, good evening again.

Must admit, the defective paint finish bears all the visual hall marks of either Stain, or Shellac original finish, reacting violently to the last application of paint ?

Other conjecture? a chemical [Pant] problem between the new and existing paint systems?

One final question? did the painter applying the last coat of paint do any filling?

You could ask the Painter to return to tender an opinion?

Ken.

 

[allthebuttons]

Evening Ken!

If the window ever had shellac or stain, it would have been decades ago, but I suspect it was white paint from the start (1914). When we moved in, it was painted white. Even if there was shellac, I think it’s unlikely that the latest coat of paint would react with something multiple layers down?

There was very heavy rain recently, and the outside of the window is starting to get a bit flakey... do you think it’s possible the wood just got damp and it travelled to the inside?

 

[KenGMac]

allthebuttons, Hi

Short answer is yes, if rain is driving in because of defective external paint then that could be a major factor? especially if there are visible gaps in the external timbers? --- is there any way you can undertake a visual close as possible Inspection of the state of the external paint finish and look for any gaps in the timber joints??

Do you have access to a "Damp Meter?" these devices can be useful in diagnosing a defect.

Certainly if rain water is entering then that could be a causation for your internal defective paint finish.

Ken

 

[allthebuttons]

Thanks Ken. There are certainly some cracks in the external paint - I’ve been meaning to paint it!

There’s no rot evident, thankfully, so any dampness is a recent thing.

If I paint it now (externally), will I just be sealing in damp? Or does it dry out fairly quickly once the weather is warmer?