Simple question... Penetration for water line

Hello everyone! I am running some small black poly tubing up to my swamp cooler as a water line (existing copper line is a nightmare so sealing up and starting over).

I was thinking I would just drill a small hole about the size of the poly tube and spray lots of flex seal around the top and bottom of the hole around the water line.

Is this feasible? If this is an acceptable plan, is there an optimal position on an asphalt shingles to drill the holes? Thank you!!

Flex seal is a complete joke and would be the absolute last way you should waterproof something (sorry to burst your bubble homeowners). Would it be possible to run the pipe out somewhere else? Through the siding perhaps? That would be a better option.


Post some pics for more detailed advice.

You can use some type of other flashing and run the pipe through that.

Something like a 4" flapper vent or a small EPDM pipe flashing.

If it’s flat or small slope, buy a small pitch pocket. The other choice for that small is what Axiom said. I call it a witches hat, but it’s a multi size accordion style. I buy them from metal roofing supply

Make a pitch pocket out of a tomato paste can. secure and seal it to the roof with compatible sealant. NO idea of what roof system you have. Pack the hole around the tube with paper. Fill the can with self leveling polyurethane.


Dark you are old school and I would love to work with you for a month or so! As long as we didn’t drink I’m sure we would get along great. Can the pitch pan be an old pear or peach can or does it have to be tomato paste?

1 Like

Actually the original was an emergency pitch pocket designed out of a progresso soup can. Cut the bottom off, split the side, 5 - 1 1/2" cuts up the sides. Wrap it around and overlap the flanges adjacent to the split, screw it down and fill it up. Left the label on it too!

1 Like

Thanks for the reply! The HOA wouldn’t allow the tube to be visible. So it’s pretty much just the roof penetration. Any way to get away with a hike just about as big as the poly tube and not use a flashing? What sealant would work?

Need a pic of the roof…

That’s a pic from the inside. I’m going to abandon the copper line and drill a new hole for either the poly tube or pex. Might try to drill through the sealant in the copper tube flashing since it already exists. Thoughts?

It’s been snowing and raining the last couple days so haven’t been able to get up top for pics. The copper goes into a flashing that sticks up about 6 inches and the copper compression joint is what failed when I looked at it wrong…

Is the roof shingles? Dwanna play 20 questions. Cut the copper off, pull it, shove the new tube through the existing hole. Seal it at the tube. Don’t use spray screen door boat maker. black polyurethane holds up pretty good.

Haha. Sorry. I’m an IT guy with mild construction proficiency trying to do roof repair! They are asphalt shingles and when I tugged on the copper line, it felt pretty firmly glued in there. So the chances of pulling it out without significant roof damage seemed low.

I was thinking of drilling into the sealant to run the poly tube through… Then re-seal it… That a good idea? And not sure what "spray screen door boat maker is… ?

Thank you!!

Screen Door Boat Maker = Flex Seal, watch the commercial… Were you to cut the copper tube both sides and twist it with pliers/vice grips, something will give.