Insulation, Radiant and Vapor Barriers - Vapor Barrier in ceiling of a proch

I'm renovating a porch/mud room which I have already insulated with R-12 and was wondering about the ceiling. I have insulated it as well but don't know if I should put vapor barrier on the ceiling. We plan to have the room heated during the winter months.

Mark

Hi caemar and welcome. Since it will be a heated area and especially since it may have to handle excess moisture from snow and such, a vapor barrier below the insulation would be desirable, exterior walls as well (always on the warm side of the insulation). Any place where warm moist air can access colder surfaces there can be condensation. FYI, I believe the recommended insulation is currently r-49 for ceilings and r-21 for walls and that was on the verge of going up last time energy costs spiked.

Good Luck,
Bud

As this is an older home, 1910, the walls are 2X4 and I will be adding styrafoam insulation to the outside and new siding this year to bring it upto the energy guide specs.

Snow has finally melted here so I'm just getting back to my foam project, similar 2x4 walls. Are you going to add over your siding or remove the old. New windows? Glad to share what I have chosen when you get there.

Bud

Hi, carmar. Welcome! I think one of the best articles on vapor barriers is:

BSD-012: Moisture Control for New Residential Buildings — (http://www.buildingscience.com/documents/digests/bsd-012-moisture-control-for-new-residential-buildings?full_view=1) Take a few minutes and enjoy...... It mentions foam and a poly v.b. together, but ......... you'll find it. Be safe, GBR