Insulation, Radiant and Vapor Barriers - Whats the best tape to join poly sheet?

Is there a recommended tape for joining a moisture barrier?

I was going to use duct tape.

The tape made for tyvek is an option..

I wouldn't use duct tape, it isn't unusual to find that within a few years the adhesive has dried out and the tape falls right off.

I would recommend the tyvek tape as well, I think all the big box stores carry this type of tape and most have their own brandname on the tape. I think you will get better results with this over duct tape.

Tyvek tape is best. You can also use a acoustical caulk, but this can get messy and is not as easy to apply as the tape.

Not sure where your application is... but I would fold the edges of your moisture barrier seam together a couple of times... and staple to the studs rather than trying to tape them together.

tx

Application is a crawlspace moisture barrier. I ended up doing a 3ft overlap (I had loads of 10mil poly being as the smallest roll was 20ftx100ft and the room is 9ftx12ft), did two seams of silicone caulk, put a row of bricks on top of that and 4 rows of the best, stickiest duct tape I could find in HD. I thought it might be a little bit of an overkill but that tends to be my way.

I think it should last, being as the ground under this space is not even damp anymore, following the the re-grading and drainage work I did outside.

It p***ed down in boston all weekend and nothing came through anyway before I finally put the sheet down.

Sounds like you got it... Good work, and good luck.