Vinyl windows - caulk between window frame and J-Channel?

[Larry]

Hi,

We have a new house with vinyl siding and vinyl windows. We noticed that
the builder caulked some of the windows (and not very well...) and didn't do
others. The windows are TwinSeal (made by MW Windows I beleive) single hung
type. With these type windows and vinyl siding, is it necessary to caulk
between the window frame and the J-channel of the siding?

Thnx in advance for any info on this.

Larry

[Mac whiter]

Hi Larry,

There was a lengthy and heated discussion on this group recently on the subject
of whether vinyl siding is designed to leak around windows. The discussion
centered on the proper installation of housewrap under the siding.

Caulking around the window where it meets the j-channel won't hurt. It
probably won't hurt much if it isn't, as long as the opening was properly
wrapped with housewrap before the window was installed.

The place you don't want caulk is where the weep holes are located at the
bottom of the window. If those get caulked closed, your windows will leak.

The siding is going to be cut 1/4" or so short inside the j-channel anyway, so
you'll still likely have a small amount of moisture infiltration at that
location, but that should be protected by the properly installed housewrap
underneath. Any moisture that enters will be able to find it's way out through
the weep holes built into the siding.

[Larry]

Thnx for the reply, Mac

House wrap was used during the construction, so that should help. I called
the manufacturor and even though it's listed as an "optional" step in their
window installation instructions, they highly recommend that the home owner
caulk around the window frame. Since we saw and bought the house after it
was built, we don't know how the builder installed the windows....so I'll be
caulking.

Out of curiosity, I looked at a home that is being built behind us
(different builder from our house...) using vinyl siding and vinyl windows
and they didn't use house wrap or caulk behind the vinyl window flap that is
nailed to the sheathing....goo chance for a leak there ;)

Larry

Post by Mac whiter
Hi Larry,
There was a lengthy and heated discussion on this group recently on the subject
of whether vinyl siding is designed to leak around windows. The discussion
centered on the proper installation of housewrap under the siding.
Caulking around the window where it meets the j-channel won't hurt. It
probably won't hurt much if it isn't, as long as the opening was properly
wrapped with housewrap before the window was installed.
The place you don't want caulk is where the weep holes are located at the
bottom of the window. If those get caulked closed, your windows will leak.
The siding is going to be cut 1/4" or so short inside the j-channel anyway, so
you'll still likely have a small amount of moisture infiltration at that
location, but that should be protected by the properly installed housewrap
underneath. Any moisture that enters will be able to find it's way out through
the weep holes built into the siding.