Expert: Bruce E. Johnson - 7/23/2009

Question
The caulking around our windows are cracked and I wanted to fix that. I was wondering what kind of caulk to use that is paintable. We have all four seasons here so it would have to withstand hot and cold temperatures.

Our siding is 1/2 in. thick and the acrylic urethane caulking I bought is only supposed to be used to 1/4 in. deep. That seemed like a good caulk with a 50 year warranty I think, and I am curious if all brands are like that. I wanted to avoid using silicone if I could.

Thanks

Answer
Hi KC, commercially we use a product call Vulcum, or another similar product Eucolastic.  They are both urethane caulks and can be used for deeper situations.  I think the caulking you have chosen is probably very similar and I wouldn't hesitate using it if I were you.  If you have areas that are extremely deep you can get "backing rod" which is a foam rope that you press into the joint until it is just 1/4" below the surface.  You then caulk over the backing rod.  It can be purchased in varying thicknesses at you local big box home improvement store such as home depot or lowes.  It is found in the weatherstripping aisle.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com