Caulk siding?


Old 08-13-06, 07:32 PM
Thread Starter
Join Date: Aug 2006
Posts: 1
Received 0 Votes on 0 Posts
Red face Caulk siding?

I'd like to know ... with aluminum siding, when caulking, do you caulk the j-channel. At the top and along the sides or leave it open "for breathing" ? Or just the bottom under the window? What about caulking or sealing the "lip" or bottom of the siding to the foundation or (is it) underlayment? Or would you use the spray foam insulation along the bottom edge of siding to seal out the cold air.?
My gas heating system was replaced (and taken OUT of the floor) with a hvac system that was put in the attic along with vents and returns(I don't recommend doing this!!). So I'm trying whatever I can to minimize costs; which had almost doubled, lately tripled. The house was built around 1928, plaster and lathe and sheetrock, once its cold its COLD, and vice versa.
Sponsored Links
Old 08-13-06, 07:37 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,967
Received 5 Votes on 5 Posts
You want to use caulk minimally on siding. It is meant to repel vertical water and caulking it will reduce its breathability. Moisture can build up under it and ruin everthing. If you see areas where water may infiltrate, of course, caulk them, but as a general rule it does its job without it.
In addition, your siding is the least of your heat loss problems. It is the insulation and air infiltration barriers that must be addressed.
Old 08-14-06, 04:06 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 25,822
Received 641 Votes on 593 Posts
You absolutely, positively, DO NOT caulk the inside of any j-channel or along the ends of each piece aluminum siding. Aluminum siding is not "water tight" or "air tight", nor is it meant to be.

As Chandler mentioned, use caulk sparingly, because the caulk's main purpose would be to improve the appearance of the siding. Adding a bunch of caulk will most often make a job look worse, not better. There are very few locations where caulk will improve the appearance, but some of them might be the OUTSIDE of the j-channel, where it meets the window trim, or possibly the top edge of a finish trim where it meets the sill- underneath the window.

As Chandler also mentioned, caulking aluminum siding will do little to nothing to reduce your energy bill. You could use 60 tubes of caulk and it probably would not reduce your heating bill 10 cents. Aluminum and vinyl siding are by design, not air tight.
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: