Silicone / Caulk Internal Windows

[steveoelliott]

Hi,

 

Many of my windows have had silicone sealant applied around the inside in the past and having recently asked a decorator to quote for a job, I asked if he could cut out and renew the sealant as it was looking old and tired. He said they use caulk as opposed to silicone and explained that he isn't able to get a great finish with silicone.

 

The challenge with caulk is, I have had this applied to windows elsewhere and whilst it looks good at first, in time it inevitably cracks and looks nasty as opposed to silicone that has more "stretch to it!"

 

Thanks.

[Russell griffiths]

You cannot paint over silicon, you can with caulk. 

Does it need to be painted ?

can you get it cut out and decorated, then silicon over the top as a neat finish. 

 

Or use a hybrid pu adhesive which is flexible and can be painted. 

[Carrerahill]

31 minutes ago, steveoelliott said:

Hi,

 

Many of my windows have had silicone sealant applied around the inside in the past and having recently asked a decorator to quote for a job, I asked if he could cut out and renew the sealant as it was looking old and tired. He said they use caulk as opposed to silicone and explained that he isn't able to get a great finish with silicone.

 

The challenge with caulk is, I have had this applied to windows elsewhere and whilst it looks good at first, in time it inevitably cracks and looks nasty as opposed to silicone that has more "stretch to it!"

 

Thanks.

+1 on above. Ask him to use polyurethene sealant. Better than silicone in many ways and over paintable. 

Edited February 8, 2023 by Carrerahill

[Bozza]

My painter told me only to ever use acrylic caulk, to prevent cracking.  I tend to listen to pros advice.

 

 

[Nickfromwales]

1 hour ago, Bozza said:

My painter told me only to ever use acrylic caulk, to prevent cracking.  I tend to listen to pros advice.

 

 

No good around a door which gets slammed / there's movement around the perimeter of.

[Radian]

Everbuild Puraflex 40 is an example of a hybrid polyurethane sealant which has a lot of stretch and is paintable. There are also products known as Modified Silicone that have the benefits of both systems. i.e. paintable, workable and stretchable. Soudal Fixall and Everbuild Stixall are two examples. I would advise anyone to grab a few different types and test them out to see which you're most happy with.

[MikeGrahamT21]

I’ve tried so many different things over the years, started with caulk, then siliconised caulk, moved onto Everbuilds 25LM, and just recently I’ve had to do them yet again, this time I opted for CT1, time will tell! It best bloody work at £14 a tube!

 

it certainly seems to have stuck well.

 

before you apply, lightly sand both surfaces, the wall and the frame, clean it with alcohol wipes and don’t stick your mitts in the silicone to smooth it out, a concave finish will always have weak points, get a proper tool to create a wedge shape

Edited February 8, 2023 by MikeGrahamT21

[steveoelliott]

Thanks all... I've been told the HB42 Caulk is supposed to be super flexible,

[Carrerahill]

15 hours ago, Bozza said:

My painter told me only to ever use acrylic caulk, to prevent cracking.  I tend to listen to pros advice.

 

 

Latex/acrylic caulk is the very stuff that is prone to cracking and shrinkage. OK for caulking when used properly, i.e. a deep fill without half of it removed with your finger leaving a thin bead. 

 

If you want to seal things and overpaint then a PU sealant is critical. 

[Radian]

56 minutes ago, steveoelliott said:

Thanks all... I've been told the HB42 Caulk is supposed to be super flexible,

£2 a tube should be telling you something when the others mentioned here go up to £14!

[steveoelliott]

28 minutes ago, Radian said:

£2 a tube should be telling you something when the others mentioned here go up to £14!

I get your point but irrespective of price it has some good write ups. Ultimately it's not really a price dependent decision.

[Radian]

1 minute ago, steveoelliott said:

I get your point but irrespective of price it has some good write ups. Ultimately it's not really a price dependent decision.

Are those reviews relating how long the acrylic lasts for? Usually people don't come back with that kind of review a couple of years down the line. When I go to all the trouble of prepping, I want the job to last!

[steveoelliott]

11 minutes ago, Radian said:

Are those reviews relating how long the acrylic lasts for? Usually people don't come back with that kind of review a couple of years down the line. When I go to all the trouble of prepping, I want the job to last!

I get it... So for you, Everbuild Puraflex 40 is the choice?

[Bozza]

2 hours ago, Carrerahill said:

Latex/acrylic caulk is the very stuff that is prone to cracking and shrinkage. OK for caulking when used properly, i.e. a deep fill without half of it removed with your finger leaving a thin bead. 

 

If you want to seal things and overpaint then a PU sealant is critical. 

You may well be 100% correct,   I’m merely repeating what my decorator told me.   Relating to my 2 year old new build timber frame, that has no decorative cracks, when I expected there would be,  and surprised when there wasn’t.   I remember asking him why pops but no cracks when he was snagging after a year, he said because he uses acrylic caulk.  May not relate to every decorative scenario of course.