Building a log cabin with loft. Have installed metal roof on 1x4 strapping which is on top of 2x10 rafters. Slope is 1:8 . Used mainly in the summer and fall - occasional weekend in winter. How should I insulate so I don't get condensation damaging the pine ceiling I intend to install on the under side of the rafters.
2006-12-08 13:01:50 · 7 answers · asked by Jerry P 1 in Home & Garden ➔ Do It Yourself (DIY)
First off, condensation is formed when vapour reaches the dew point, which is its right between water/ice's freezing and melting point. To stop this ensure you install a vapour barrier on the warm side of the insulation, no matter what kind of insulation you use. Ensure this vapour barrier is continous as any penetrations in the vapour barrier has the ability to transfer a gallon of vapour daily your humidity conitions are high.
Second, ensure you have a minimum of 2 1/2" of ventilation running from your soffit vents (your roof overhang) to your ridge vent (yes you will need a ridge vent unless you have even a small area of horizontal ceiling at the top of your cathedral ceiling where regular roof vent will work). Just ensure that your roof rafters are large enough to provide the 2 1/2" airspace from your insulation.
2006-12-09 02:49:16 · answer #1 · answered by Building Inspector 2 · 1⤊ 1⤋
Use kraft faced insulation for attics R-19. It won't fill the whole cavity, but will instead provide room for ventilation. Staple it tightmaking sure all gaps are filled. Next, hang sheetrock on the ceiling. My brother omitted this step and gets a lot of cold air bleed down. Then put on your pine. It wouldn't hurt to install a ceiling fan up there too, especially if you are using some sort of non vented gas fireplace or heater. They put out humidity.
2006-12-09 13:09:04 · answer #2 · answered by gensler97 2 · 0⤊ 0⤋
the trick is to keep both sides of the metal at the same temp. that means ventilation. in your case a vented ridge and vented overhang. put sheets of insulation on the underside of the 2x10's and use long nails to fasten the vaulted ceiling. don't put any insulation between the rafters. or as long as you have the width you could use maybe 2 inches of styrofoam on top of the ceiling. Just be aware you need lots of ventilation.
2006-12-08 13:17:23 · answer #3 · answered by La-z Ike 4 · 1⤊ 1⤋
THE CORRECT ANSWER IS U SHOULD HAVE PUT DONE 1/2 OSB OR CDX PLYWOOD WITH A MINIMUN OF 30# FELT UNDERLAYMENT OR I PERFER GRACE ICE AND WATER SHIELD MEMBRANE. THEN U COULD USE 1X4S OR SCREW METAL DIRECT TO DECKING. IF USING 1X4S MAKE 1/8 -1/4" SLOTS SO THAT AIR FLOW WILL DRY OUT EVAPORATION. THEN IF U WISH, INSULATE BETWEEN RAFTER FOR ENERGY EFFICIENT.
2006-12-08 13:38:14 · answer #4 · answered by john t 4 · 0⤊ 1⤋
use 8" batts between the rafters. leaving about 2" for ventilation.
2006-12-08 13:27:48 · answer #5 · answered by T C 6 · 1⤊ 1⤋
I would use spray on for that application, its made of paper glue and fire retardant, I used it in a parking garage really good for filling in all the cracks too, good luck
2006-12-08 13:15:44 · answer #6 · answered by edgarrrw 4 · 0⤊ 1⤋
use a coating called supertherm it is wheather proof material white in color it will not allow heat transfer
2006-12-08 21:59:56 · answer #7 · answered by sb r 2 · 0⤊ 1⤋