[fromthenorthwest]

95% of my jobs this gap has already been caulked, whether it's a repaint or new construction. But occasionally as is the case today, I've come across one where that gap is not caulked. Generally my rule of thumb is 'if it's not already caulked, don't caulk it now.'

I've heard it said that a properly enveloped building shouldn't be relying on caulking to repel leaks. And I have seen uncalked windows where there appears to be no weather damage to the trim. But I also have seen plenty of instances where a crack in window caulking revealed major rot behind said crack.

So I wonder what gives? What's your experience been with caulking (or not) the window/trim gap?

Here's a picture of one of the windows from today. As you can see the trim still appears to be in pretty good shape, other than at the sill.

 

[Holland]

95% of my jobs this gap has already been caulked, whether it's a repaint or new construction. But occasionally as is the case today, I've come across one where that gap is not caulked. Generally my rule of thumb is 'if it's not already caulked, don't caulk it now.'

I've heard it said that a properly enveloped building shouldn't be relying on caulking to repel leaks. And I have seen uncalked windows where there appears to be no weather damage to the trim. But I also have seen plenty of instances where a crack in window caulking revealed major rot behind said crack.

So I wonder what gives? What's your experience been with caulking (or not) the window/trim gap?

Here's a picture of one of the windows from today. As you can see the trim still appears to be in pretty good shape, other than at the sill.
View attachment 114689

The way the weep holes are at the bottom, makes me think that the edge of the window should be caulked.

edit: agree with coco about the carpentry.

 

[Joe67]

Regardless of what has been done in the past or whether it needs it for weatherproofing or not, I caulk gaps like that for aesthetic reasons. The window is white. The trim is X color (olive-ish green in this case, but going to whatever you're putting on). The gap is a weird black line...

This is all as long as it isn't a drain (like those weep holes) or some kind of aeration space. But I'd be caulking those side gaps.

 

[cocomonkeynuts]

Just looks like sloppy carpentry, caulk it

 

[ParamountPaint]

I think you could caulk it, but I'd leave the bottom inch or so open. Without tearing the trim off, its hard to say what was done behind there.

In theory, caulking the whole thing could block moisture in, but I think it would be unlikely if you left a gap in the caulk at the bottom.

 

[finishesbykevyn]

I have the exact window trim setup on my house. Caulk the **** out of that. I don't like how that bottom piece of trim sticks out proud of the other ones. Sloppy carpentry is right.

 

[Respec]

I agree with everyone. And to the point of "the last guy didn't do it", if you only want to be as good as the last guy, skip it, but if you want to build a solid reputation for yourself, do what you think is right. We all have seen completely hack paint jobs.

 

[ssewall]

You don't need to caulk that gap on a high quality window installation, and it may or may not make things worse on a low quality one. If I'm not sure about the substrate, and there are no signs of problems, I don't caulk it if it isn't already caulked. If the house has obvious issues due to poor installation I discuss it with the customer first.

 

[thesse106]

it looks like caulk was removed. I get those curls of wood when I hit th eside of the board with my blade. the caulk probbaly peeled off really easy. the bottom is still caulked. anything that gets back behind that board is going to seal behind the sill caulk. eventually rotting out the inside. I would sell them on the caulk of that and any others.

 

[finishesbykevyn]

You don't need to caulk that gap on a high quality window installation, and it may or may not make things worse on a low quality one. If I'm not sure about the substrate, and there are no signs of problems, I don't caulk it if it isn't already caulked. If the house has obvious issues due to poor installation I discuss it with the customer first.

One would hope that they sealed and blue skinned around the window, but the way that trim was installed is just a water catcher regardless. I would keep as much water out as possible. Most of the time, a home owner doesn't know there is a problem until it's too late. Most importantly, I hope they have drip edges above the window.