Comments on: Insulation R-Value

By: Ben Erickson

Ben Erickson — Thu, 21 Jan 2010 20:27:36 +0000

Jenn,
Keeping your pipes from freezing isn’t easy if the crawlspace under your house isn’t enclosed, but here are some tips:
Use pipe (like PEX) that resist breaking when the water freezes.
Bury the pipes and run them straight up to the plumbing fixtures to reduce the amount of pipe you need to insulate.
Wrap heat tape around hot and cold pipes (unplug when above freezing) followed by foam insulation.
Drip faucets when the weather is below freezing.

By: Jenn Jones

Jenn Jones — Thu, 21 Jan 2010 14:17:07 +0000

Thanks Ben!
My son and I got into the attic this past weekend and guess what we found??? NO Insulation whatsoever!!!! Just wood ceilings and rafters with Tin overhead! We have measured and are getting ready to get started. Most of the rafters are logs, the others 2×6. I plan to lay R-30 down first inside the logs (30″ in between so will use 2 x 15″ rolls)and go back another time and add more cross the logs. It appears that R-30 is no longer the standard minimum. Looks like R-38 to R-49 is more the current minimum. Since I have no insulation, I should see a huge difference in comfort and bills just from the R-30! Will tackle underneath later as you suggested. Thanks for your help. Now if you can tell me how to keep the pipes from freezing under the house, I am all ears!

By: Ben Erickson

Ben Erickson — Wed, 13 Jan 2010 14:45:00 +0000

Jenn, Since most heat and cool loss is through the attic, you're right to tackle it first. If possible, it's important to provide adequate ventilation in the attic to remove hot air and prevent condensation (see our articles on Attic Ventilation and Soffit Vents), which it sounds like would be hard to do in your case. As far as under the house goes, it would be okay to attach OSB to the bottom of your joists. You might want to screw them on with drywall screws and a cordless drill so you could easily take it off in case it floods and the insulation gets soaked. Good luck with your project!

By: Jenn Jones

Jenn Jones — Tue, 12 Jan 2010 15:41:44 +0000

Hi Ben,

I can’t close in the foundation because there is a creek about 200 or so feet away; water has only entered the house once, during Hurricane Camille and only because of storm surge backed up all rivers and creeks. Just in case the creek were to ever rise that high again, I need water to have the ability to flow versus rising. I am going to check this weekend to verify if I have 2 x 6 or 2 x 8 joists and if they are 16 or 24″ centers so that I can buy the right size of insulation. If I buy faced and staple with facing close to floor, at most I will leave an inch and half from the bottom of the joists. This air flow should assist with moisture evaporation, so I think the 6.5 inch, R-19 will be ok. I am looking at osb board to put on the bottom of the joists, what do you think?

Also, I will ck this weekend to see how much, if any, insulation is in the attic. Since warm air rises, I think my first attack should be in the attic and then the floor. I used a calculator and it said to insulate to R-49 for this area. The farm is in Wayne County Mississippi about 5 miles from Millry Al. Currently, there is no attic access, but it has a metal roof. I am thinking of blowing insulation in by removing sections of roofing. Any advice would be appreciated.

By: Ben Erickson

Ben Erickson — Mon, 11 Jan 2010 16:27:03 +0000

Hi Jenn, If possible I would start by closing in the foundation around your home, then add insulation between the joists with 6" insulation (which should be plenty), holding it in place with specially made support wires. Check out the article and video from our Scariest Utility Bill episode to see how to go about insulating under a floor.

By: Jenn Jones

Jenn Jones — Sun, 10 Jan 2010 13:23:22 +0000

I inherited my grandfathers farmhouse built in 1900. Although I grew up playing there and visiting since then, it is now my responsibility to take care of it. We have spent the last year working on the obvious and last year we only had a fireplace for heat. After purchasing a propane tank I thought my heat problems were over, Wrong! After examining under the house with about a 16 inch crawlspace, I have discovered that there is no insulation or sub floor. Only hardwood floors over the 2X6 joists. I have been researching insulation and after seeing your show on the weather channel I still have questions. Would an R-19 with facing be sufficient? Also, since this is literally off the ground (no basement) should I enclose the insulation? It appears that I should put in batting face side to floor and am considering using a basic plywood across the joist. There are also insulated sheats that say they are indoor/outdoor with “R” ratings and they state that they even hold up to immersion in water, but I am unsure of these for an exterior surface. Since I have 6 inch joist, should my insulation be 6.5″ (R-19) and would the plywood or the insulated sheaths be best? How much improvement in comfort and utility bill should I expect? There is nothing blocking the wind from coming underneath the house. Thanks

By: Ellis Farris

Ellis Farris — Thu, 07 Jan 2010 21:40:36 +0000

I live in Raleigh North Carolina and would like to insulate my attic. My house is approximately 1600 sq feet and was built in 1963. The attic has had no upgrade of insulation since. It now has roughly 3 to 4 inches of blown cellouse insulation. I am leaning towards insulation of pink fiberglass with a R-38 rating. The thickness would be 12″ and a width of 16″. Is this enough insulation? I’m not sure of the square footage of the attic yet but I’m assuming it will take between 25 and 30 rolls. Thank you. Ellis Farris

By: Mike Dingas

Mike Dingas — Sat, 02 Jan 2010 17:21:54 +0000

I forgot to mention that the building is clad in aluminum siding. Also, moisture control is important as my area is very humid most of the year

By: Mike Dingas

Mike Dingas — Sat, 02 Jan 2010 17:17:30 +0000

I need to insulate a 12×24 steel framed workshop. It’s a sweatbox in summer and an icebox in winter! I live in central Georgia. Any thoughts on how to best accomplish this and choice of insulation is greatly appreciated.

By: Wen S. Tsau, PE(C&R)

Wen S. Tsau, PE(C&R) — Mon, 02 Nov 2009 12:38:31 +0000

Can you please send me the Fiberglass Insulation K-Value vs. R-Value Comparison Fact Sheets?

Thanks.