Repairing cracked caulk around exterior window trim

[Murdoc]

I have a 1920's colonial that was vinyl sided in 2003 by a previous owner. They used metal trim around the exterior of the windows. On most of the window sills, the caulk is cracked:

Though, most of the windows are not that bad. Most have a 1/16" to 1/8" crack. I'm worried about rain water getting underneath and causing damage.

Any advice on repairing these? What product to use? Is there a caulk / sealer that will go over the old stuff?

 

[Greenman]

Sikaflex almost certainly has a product for the job. Good stuff that seems to hold up very well.
http://usa.sika.com/en/home-page-features/product-finder/iframe_and_dropdown/sikaflex.html

 

[mizzou]

I would say check for water damage before sealing..but who knows what youll find!

Im also an old homeowner but I still have the original wood siding. Victorians look like crap with new vinyl siding...and usually its just layed on top of the old siding anyway.

Maybe probe around for bad rot before sealing amnd make sure to get rid of the old cauking.

Greenman, what caulk do youthink he should use?

 

[Greenman]

I would say check for water damage before sealing..but who knows what youll find!

Im also an old homeowner but I still have the original wood siding. Victorians look like crap with new vinyl siding...and usually its just layed on top of the old siding anyway.

Maybe probe around for bad rot before sealing amnd make sure to get rid of the old cauking.

Greenman, what caulk do youthink he should use?

It's a 90 year old house that's been covered with vinyl siding, I would guess there is a great deal of water damage and rot that was covered up, because you don't reside a house with serviceable siding on it. So the next question is, does he really want to know what's under that vinyl? Before starting down that road you have to be ready to write some big checks.

As far as caulking goes, I use a lot of Sikaflex 1-A. It's quality material, and available everywhere. It's about 5 times the price of basic dap that everyone uses, and worth every cent of it.
It's also a solvent based material, tougher to use and a bitch to clean up.

 

[Murdoc]

Thanks for the replies.

I can't find Sikaflex 1-A on Home Depots website, but they have:

Sikaflex 10.1 fl. oz. Construction Sealant , which looks like it would work.

Can I put it right over the old caulk?

 

[Greenman]

I've never heard of Sikaflex Pro. My guess is it's a product made exclusively for the Home Depot, and probably inferior to their standard offerings. I'd look elsewhere for the 1A. Any lumber yard should sell it.

It's best to remove as much of the old caulking as possible, otherwise your depending on the bond from the failed caulking to maintain a waterproof seal.

 

[bbhaag]

I'm gonna have to agree with Greenman. Remove the old cualk before applying the new stuff.

 

[Murdoc]

Thanks guys. I'll keep looking for the 1A, and I'll remove the old caulk.