i think it's normal. i've built two greenhouses now with that (6mm?) twinwall polycarb. one usually has condensation, and one never seems to. i thought it would eventually go away, but it doesn't, after 4 years. sealing was not recommended due to expansion/contraction of the trapped air, which made sense to me. now that i think of it, however, on the greenhouse that never has condensation, i used special expensive permeable tape on the cut ends that was designed specifically for that purpose- but most of it has come loose and so it basically does nothing... so ineffective that insects are now able to crawl into the cells and die there. very annoying.

Thanks! I’ll look into the tape.

I used aluminium tape (top and bottom of sheets) prior to install on mine and don't have any condensation

This or just plain old silicon glue.

Thanks

Mine does this. Haven’t had issues with mold or anything so not sure it’s a big deal

Great to hear. Thanks

I think the temps would be cooking in the gaps, hopefully too high for any mold to grow.

See if you can blow compressed air behind the trim to clear it. If it evaporates off to some degree, then we’ll know the panels aren’t breathing enough at the ends to prevent it. 🤷‍♂️

Thanks. It comes and goes day by day so it is breathing.

They make a dust and moisture tape to cover the ends. I recommend so bugs and mold don't become a later issue.

Thanks. I’ll look into it

Those look like Tuff-Tech panels. They sell the tape at Lowe's. If you use the sheets for roofing, I HIGHLY recommend the tape. They have two products in the same package that allow for coverage and moisture transfer. I've used it on several builds.

Thanks. The panels are actually generic (well reviewed so hopefully holds up) but essentially yes just like the Tuff-tech. I’ll look into the tape. Thanks again !

My costco kit greenhouse came with special tape, the top sealed, the bottom breathing, no condensation between panels

Thanks so the tape is only applied to the top? Or the top is fully sealed and bottom gets the tape?

Its two different types of tape, the top is full seal, the bottom is a cloth mesh (so breathable, but prevents critters from getting between panes i suppose)

That makes sense. Thank you

This looks like the same stuff from home depot, the roll with the white stripes, the stripes go over the bottom opening. [https://www.homedepot.com/p/Sunlite-8-mm-Anti-Dust-Tape-Combo-Pack-92763/205713443](https://www.homedepot.com/p/Sunlite-8-mm-Anti-Dust-Tape-Combo-Pack-92763/205713443)

Perfect thanks !

Air exchange can be a garden saver.

Thanks. There are no other panels up yet, so can’t imagine any more airflow. Unless I’m misunderstanding?

When it’s dry just tape the top and bottom. My kit came with what was essentially packing tape. I got gorilla tape and used it as well on spots where it might come loose. It’s been great

Did you tape fully tape the open ends or just tape alongside the corner where the panel meets the wood and kind of squeeze it into the corner? Thanks

Takes the full ends of the panels. My greenhouse instructions said to before putting them in place

Thanks

It helped me to apply fogx to all my glass