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rambleonrose's avatar
rambleonrose
Explorer II
Feb 11, 2020

Ceiling insulation help!

Hi folks! We're In the beginning stages of a complete gut/rebuild, and really just making things up as we go along, lol!

We're about to put insulation in the ceiling, and we're not sure the best and most economical way to go. The space between is about 2" thick, 150 sq feet. Because this is an unexpected complete rebuild, cost is a huge factor - we don't mind using leftover, weird, or otherwise unconventional things for certain aspects of it.

For insulation, the usual cheapest route is the pink roll, but that's too thick for a space that's only 2" thick. We looked at the spray-in foam, but that's hundreds of $... Same with the rigid kind that we pulled out (was rotted and soaking wet...)

So... Should we try to slice the pink stuff in half and use it? Any other thin methods out there we might look into?
  • Sheet foam with minimal expanding spray foam on the seams. For foam to show rot it has to be very old or exposed to UV rays. And it has to break down to absorb water.
  • gvisnic wrote:
    google 2" insulation. All kind of options


    Thank you for this extremely helpful reply.................
  • Boomerweps wrote:
    Sheet foam with minimal expanding spray foam on the seams. For foam to show rot it has to be very old or exposed to UV rays. And it has to break down to absorb water.


    The foam we pulled out was pretty bad, and a good amount of it was soaked with water. (from an '87, who knows how long it was wet...). The whole RV and roof was bad, hence the gut.

    Sheet foam isn't ideal, because one of the roof repairs involved putting in aluminum square tubing beams, with an arched wood beam on top to make the roof slightly bowed (plus, it was super warped and a curve was the only thing we could come up with to take up the slack...)

    That's why we were thinking of something soft, like the standard pink roll.... I do prefer the rigidity the sheets would give, though...
  • I've been following RV Roof Install over on youtube. Maybe browse through the vid's and see if you can grab some inspiration.

    RV Roof Install
  • If you use foam in need to be closed cell type. That means NO cutting to fit.

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