Which area, attic or basement ceiling, would provide the biggest improvement in reducing heating/cooling costs and increasing comfort in our zone 5 ranch with walkout basement?
Asked by Piper Lee 
8 months ago
Last Updated: May 1, 2024
Hey, we’re thinking about adding some insulation either in the attic or our basement ceiling. What do you think would make the biggest difference?
We’re in zone 5 in the US, living in a ranch-style home with a walkout basement. Right now, the attic has about 8-10 inches of insulation, but the basement ceiling isn’t insulated. However, the exposed wall for the walkout basement is fully insulated at R19.
Our main goal is to lower our heating/cooling costs and make the house more comfortable. We’re just not sure where to start – we’ll probably end up insulating both eventually when we have the time and money. So, which do you think would be the best for improving our situation, attic or basement?
Attic is key, aim for at least 12.5″ with blown fiberglass for an R38 value. Some areas in zone 5 require R44 for insulation.
Expressed gratitude for the rolled fiberglass, likely from the house’s 80s construction.
Considered adding unfaced R30 perpendicular to the rafters
Michael, it all depends on how much effort you’re willing to invest. One option is to air seal your attic and then have a professional blow over the existing rolls if they’re still in good shape. This can help reduce air leakage in your home. Also, remember to check if there are Batts on your attic access panels.
Cutting roll insulation just right is key for optimal effectiveness. While it may have a slightly lower R-value per inch, the challenge lies in fitting it properly, especially in tight spots like the edges where the roof slopes down.
I’m in the same boat. Eliminate any drafts or air movement. They are usually found near the chimney or in corners. You might be able to borrow a thermal camera from the library or rent one from Home Depot for a couple of hours. It can help you identify cold spots to investigate. I discovered that the insulation job done by the previous owner was incomplete in hard-to-reach areas, with rolls propped up to even out the level but not fully thick.
Oh, that’s a good point, thanks Kendrick.
Attic. Seal any gaps or holes in the air.
Heat rises, so insulating the attic to at least R40 is important. The type of insulation used makes a big difference. Professional spray foam insulation is the best choice currently. It outperforms bat or blown insulation in all aspects. Insulating the floor can reduce noise between levels and improve zone heating, but focusing on attic insulation will have the biggest impact.
Hey, insulation expert here. Attic insulation helps keep out radiant heat. If your home is too hot, start with insulation. Are you considering blown-in or batting for 8-10″? Blown-in is efficient but can settle over time. Batting quality depends on installation. Remember, R-value is a lab test number. Actual R-value for R-30 insulation can be as low as R-18 due to gaps. Blown-in is cheaper but only about 75% effective once installed. Neither blown-in nor batting are air or moisture barriers. Consider HVAC ductwork in the attic too. R-6 or R-8 insulation on ductwork may not be enough in hot attics. Leaks on the return side can cause HVAC to pull in hot air. Consider spray foam for better efficiency. I recommend against insulating between basement and first floor unless fully insulated. Moisture is the main concern in basements. Unfinished basements can use bag insulation on walls. Finished basements can use 2×4 framing with R-13 or R-15 insulation. Foamboard is a cheaper alternative. The goal is to keep moisture out of the home envelope including the basement. Hope this helps! 🙂
I saw this post by and it got me thinking – my kitchen addition is always chilly because it’s over a 3 ft high crawl space. Do you think insulating the floor could make a difference? I live in Ohio.
Hey Melissa! If the floor is above a crawl space, then yes, definitely! Building code requires at least R-30 insulation in climate zone 5, but R-19 can work in a pinch. Just use insulation stays (they’re like coat hanger wire) to keep it as close to the floor as possible.
In addition, my ranch-style house features an overhang. I encountered a wasp nest that required me to remove the soffit plywood. Upon inspection, I found the same old 3″ insulation. I replaced it with a modern product, resulting in a noticeable improvement. Surprisingly, it was quite an easy task to complete.
Do you have a ranch-style home and don’t heat the basement? That’s something new to me. How about the garage? Is it located on the same level as the walkout basement? How old is your house? If it dates back to 1980 or earlier, it might be worth considering removing the garage ceiling to add insulation. In my case, I found only 3″ of deteriorated insulation up there, extending into the walls. If you ever renovate your kitchen or bathroom, consider a full overhaul and replacement.
First things first: Start with the attic. Purchase unfaced rolls or bats and lay them in a perpendicular direction to the existing insulation. Make sure not to obstruct the space leading to the soffits. It’s important to have both soffit vents and a ridge vent. I personally use a mushroom attic fan that turns on and off automatically based on a thermostat. It’s the best way to tackle summer heat. While the ridge vent is effective for moisture control, it struggles to keep up with high temperatures. Despite what some may say, these two ventilation systems complement each other perfectly.
I live in the Northeast US where heated basements are not very common. Our house, built in 1985, does not have a garage, but there is an addition that was built in 1997 over a 4-foot concrete crawlspace.
A ranch with a walkout basement provides great usable space. I believe in finishing it. When I did mine, I made the windows larger and added another picture window. It now feels like any other room in the house. I also have a fireplace with a wood stove that heats the entire house. I’m located in NY. The crawlspace is a good spot for insulation, just like an attic. Proper ventilation is important to control moisture, but it can get cold. Here’s the window I added, all casements for a nice large glass area. I also have an atrium door on the right side.
My wife and I are slowly working on our first house. It will take some time to finish. We were drawn to the walkout basement when we bought the house. So far, we’ve updated the kitchen, installed on-demand hot water, and heat pumps, which has made budgeting tighter.
I brought up all of that because once the area is heated, there’s no need to insulate the floor. It may be for soundproofing purposes, but not for retaining heat.