My grandmother had a "sun room" added to her house and there is a leak where the roof of it was butted up against the existing wall of the house. It appears to have originally been sealed with some clear stuff and then someone came along at some point and put some black tar looking stuff over part of that. It is all cracked now, clear and tar alike. Pics are attached.

What should I do to try and re-seal this junction?

I'm also taking down some gutter sections which will leave holes in the fascia board and the metal covering it. What type of caulking or sealant should I use to seal off these holes from water damage?

 

Well, once they put tar on it they kind of hosed anyone that wants to caulk it with a sealant.

Get some Dymonic FC and caulk the perimeter with a fat tip... 1/2" or so. Then check it a couple times a year to make sure its still bonded to the tar.

 

Because it is so hard to remove the old tar? Other reason?

 

Adhesion of any material other than tar or blackjack... which aren't the best products to use there. Most sealants require a clean substrate... which is now impossible.

 

It doesn't look like they tried to remove the old stuff before applying the tar. Could it be possible to slightly loosen up the tar stuff with a heat gun and peal or scrape it away? I would guess that some of the metal may have been protected from the tar by the old caulking. Maybe I can get a lot of the tar up for this reason.

In the areas where there is no tar, should I try to remove the old caulking/sealant or just try to fill up the crevices?

Dymonic looks like a great product but we'll have to order it.

 

It is pointless to try to clean the tar off, cuz you won get it spotlessly clean. That's what I'm saying. Scraping any of it will make next to no difference for the adhesion of the next layer... because if you don't have brand new sparkling clean metal that can be wiped with denatured alcohol prior to caulking, your adhesion won't be the best.

Now if the tar surface is rough, or there are gobs that are irregular or cracking, it might help to take a heat gun and try to scrape the excess off. But the heat mayalso reactivate the tar making it sticky again, which might also affect the adhesion if you want to recaulk.

If there is old caulk and you can remove most of the old caulking that would be good.

Amazon has the Dymonic FC for about $5 a tube.

 

OK, that all makes sense, but maybe I should play with it a little. I'm not sure I can make it much worse. And, if I could get most of anything off, I do have a nice cordless high speed grinder. Maybe that could get that extra little bit off to bare metal.

 

XSleeper: You mentioned using a "fat tip... 1/2" or so." Would that be using a "sausage gun?" I wasn't aware of sausages until now but it does look like the cheapest way to buy Tremco Dymonic.

 

Not necessarily. You can cut the tip on a 10 oz tube tiny, or fat. Maximum size of a 10 oz nozzle is roughly 1/2", which is why I mentioned it.

A good bulk sausage gun and tip would cost more than the caulking would. I don't think you would want a bulk gun.

Three 10 oz tubes @ 1/2" nozzle would probably caulk up to 30 feet, assuming you use backer rod as needed.