Sealants, Caulks, Fillers... Help!

[dockofthebay]

I have a uPVC window, which has a wooden windowsill internally.

It was a new build, so over the past 9 years, the sill has expanded during hot weather, leaving some cracks in between the window and the sill. Attached an example (sorry it's so dark).

I'd like to fix this, but not sure what product to use. Opinions seem to differ everywhere I look.

The window does get some condensation during winter - not excessive, but there would be a chance of some moisture for 2-3 months of the year.

Can someone please recommended me the correct product to use?

 

[bobasd]

the crack seems to be in some kind of sealant and a beading?
can you stand back and photo the lower window frame and the wall below the crack?
ie give some larger context?

 

[dockofthebay]

Thanks - Yes, it's a crack in sealant. That's what I need to reseal.

 

[foxhole]

Frame sealant

 

[johnny2007]

Remove old sealant with a plastic tool of any kind so to avoid scratching window and windowsill.
Then use a silicone to reseal.
I like this one because it's very flexible, doesn't discolour and 3 years on i have no mould.

https://www.toolstation.com/soudal-...MI1vSZ5dej6AIVSLTtCh1m-QRvEAUYASABEgLuOfD_BwE

 

[dockofthebay]

Remove old sealant with a plastic tool of any kind so to avoid scratching window and windowsill.
Then use a silicone to reseal.
I like this one because it's very flexible, doesn't discolour and 3 years on i have no mould.

https://www.toolstation.com/soudal-...MI1vSZ5dej6AIVSLTtCh1m-QRvEAUYASABEgLuOfD_BwE

Thanks. Sounds like that's what I'm looking for.

 

[bobasd]

OP,
replacing the sealing is the obvious, and simplistic part of an answer - the important part that should concern you is what caused the condition in the first place.

 

[dockofthebay]

OP,
replacing the sealing is the obvious, and simplistic part of an answer - the important part that should concern you is what caused the condition in the first place.

Oh, I'm not concerned by that.

Edit: guess I should add, almost every new build I've known - friends, family - has had the same issue.

It happened within the first few years, has never bothered me, and I'm planning to sell this year so getting round to fixing it. It's definitely just that the wood has expanded in the heat - South facing window, so very hot.

I'm really not concerned about any underlying causes. I'm sure it could be a billion terrible things, but it could also be expansion due to heat, which it is.