Reflective Bubble Insulation

[repairguy]

Not a garage question, but this is the only 'building' forum I am on and there is plenty of mention of it in the past.

I have a modular on pilings. The skirting is 2 inch rigid foam insulation, in 4 ft pieces, coated in stucco. The gaps are just the textured surfaces touching and maybe up to an 1/8 inch gap. It works well, but on a cold day (-30) with a good wind there is enough air transfer to drop 5-7 degrees with a few good gusts.

I was thinking the double bubble reflective insulation would be easy to work with. It would create a vapour barrier. Likely be easier to install than a floppy piece of poly and it would offer a reflective surface to reflect light when working under there.

My question is will it offer any more value than poly?

The skirting is in a channel on a treated 2x4. There will be a 3/4" gap between the bubble insulation and the back side of the skirting.

I was also wondering if I should use acoustic sealant or other goop to seal it to the ground vapour barrier and underside of the home, further stopping drafts. There are 5-7 thermally controlled vents that allow air transfer even when closed (not air tight), so there is no worry of completely sealing off the area if I go to town. Just not sure if other than looking neater, and possible longevity, if there is any benefit over poly.

Any experience to share?

Thanks fellas!

 

[Stuart in MN]

Instead of messing around with the double bubble stuff, seal up the gaps in the rigid foam skirting with caulk or expanding foam or whatever is most appropriate.

 

[repairguy]

That's a lot more work. I can pull the skirting off in minutes and tack the poly or bubble from the outside. I would have to crawl underneath and fill a 3ft crack ever four feet, plus top and bottom runs for 250 linear feet If I were to use a filler.

 

[jack stand]

Are you thinking of applying the bubble stuff to the bottom of the house or to the skirting?
The idea is to keep the outside air movement out of this space right? The 2" foam skirting is apparently your insulation "shell" (below the house) I'd improve that like Stuart said above. Keep the bubble stuff for shipping purposes like it was developed for.

 

[repairguy]

The skirting sits against the house with a metal flashing screwed just under the siding that angles out to act as a drip edge and cover the 2 inch foam. The bottom of the foam sits in a track on a 2x4 with another piece of flashing that covers the top, bends down the front, and is buried under grade to keep mice out. So other than the gap between the track and 2x4 and the gap between panels it is a 'solid' barrier.

I was thinking of tacking the bubble wrap to the front of the house and behind the track so you would have a plumb sheet directly behind the foam panels to block the air flow. There are 5-7 temperature controlled vents that open to allow air transfer in the summer, but they close up only allowing a small amount of air movement in the winter. Other than the holes cut for those it would be a solid air and vapour barrier.

I was thinking the bubble wrap would be more rigid, easier to work with, and look neater while offering reflection for lights if I'm crawling around underneath. I was also thinking, before I read about the false claims of the R value, that it would add some insulation as well, but it seems I might as well just use heavy poly and be done with it.

After some hours of reading last night I am thinking a bead of acoustic sealant on the house face and behind the track with the real heavy under concrete poly is likely the route I will go. I can remove a 30 ft span of flashing and panels in 5 minutes and install the poly from the outside while also making it easy to access areas if I need to work under there. I can cut and repair the poly if I want to open it to pass anything underneath, Where as if I foam or caulk I have to climb underneath and possibly break the panels to remove in the future.

Any better thoughts?

 

[repairguy]

 

[dfiler2]

Very nice looking place. You might want to consider using house wrap which would allow some moisture to escape. I see you have ventilation installed, which is a very good thing but I'm assuming you can close those during winter. I think I would use a house wrap product and bury it a few inches at the bottom. I do think it's a good plan to keep the air from moving much when it's -30, I know it is around here.

 

[Firebrick43]

Reflective bubble insulation is snake oil. Plain and simple. The "r value" that they claim is bogus. It has an R value of about 1.1 and is really only useful as a vapor barrier on how its used typically. It can function as a radiant barrier on roofs and such but trailer skirting is going to be mainly convection/conduction heat, not radiant. Use foam insulation. So what if its harder, it will give you the best long term performance.