Fixing Insulation under trailer

Darrow,

Tyvek tape is designed to work well with Tyvek wrap. It would probably work very well in your application. Lots of other tapes will also do the job. I'd use cheap duct tape.

Dave M..

Ordinary duct tape will not hold up well with the variable temp and humidit y changes under a trailer. You need something guaranteed to adhere under t hose types of conditions. Also, I would staple the new plastic to the floo r joists as closely as reasonable, to help reduce the tension on the tape a t the seams.

Darrow:

You need to determine the purpose of that plastic.

If that original plastic was meant to be a vapour barrier, don't use Tyvek. Tyvek allows humidity to pass through it, and vapour barrier plastic doesn't. You don't want humidity getting into your insulation because it will condense and form water droplets right inside the insulation. As insulation gets wet (or even fills with frost) it loses it's ability to insulate.

If you don't know what the plastic is for, and the trailer manufacturer doesn't give you a credible answer, then I'd play it safe by using an insulation that doesn't need a vapour barrier because it's impermeable to air, such as expanding foam or extruded polystyrene insulation. That way, you side-step the need for any plastic on either side of it.

Nestork,

He's not replacing the plastic with tyvek. He has sliced open the plastic for repair work and now wishes to reseal the plastic with tape. Tyvek tape will do this. He is not replacing any insulation.

Dave M.

Trailers I have seen/been under have steel beams running the length of the trailer, and wooden crossbeams. But I haven't been under the newer models so I don't know what the current standard construction/building practices are.

Oh, Gee. If that's the case, I'd just use duct tape or whatever strong tape the OP has plenty of. Under a trailer is not a place where it's going to get much UV exposure or even get wet (unless the trailer is being moved on a rainy day). If Tyvek tape sticks well to that plastic, it would work too.

Thanks, Dave.