Staying Warm In Your Log Cabin: How To Insulate Your Log Cabin
Logs are naturally great insulators and therefore my log cabin will automatically be energy efficient and my bills will be reduced, right? WRONG.
I hear many people making this assumption, but the fact is, up to 70% of your heat will be lost through the roof and the floor.
Couple this with a log home that has been built with logs that are too thin in diameter, or a cabin that has not been built well, you could be well on your way to having a very energy inefficient home. The very opposite of what you set out to achieve I’m sure!
Make certain you don’t make this mistake by ensuring you spend time during the planning and design stage and think about how to insulate your log cabin and make it as energy efficient as possible.
Read on to find out more about the process of insulating your log home, materials to use, and step-by-step instructions of the process.
Why insulate your log cabin home?
To understand more about how energy efficient a log cabin is, you need to understand some terminology.
R-Value
The R-Value is the measurement of resistance of heat flow through a certain thickness of material. The higher the R-value the better because the more thermal resistance the material has and therefore, the better insulator it makes.
U-Value
The U-Value measures the heat loss in Watts through a material so therefore the lower the U Value the better as less heat is lost. U values take into account more factors and are therefore more accurate in determining a materials insulating ability.
These values are purely dependant on the type of wood you use for your logs and the thickness of the logs. Typically the R-Value for wood ranges from 1.41 per inch for softwoods and 0.71 per inch for hardwoods. This means a log wall built with 6-inch softwood logs has an R-value of just over 8.
Compare this to a typical wood stud wall with 3.5 inches of insulation, sheathing, and wallboard which has an R-value of around 14 you may be surprised to see that comparatively log walls are less energy efficient.
However, because of the properties of logs and their ability to store heat, they don’t tend to feel as cold as their given R-value as they can release heat back into the house as it cools – an advantage log homes have over their competitor conventional homes.
Log cabin walls
When choosing your logs, you should choose the thickest and best quality logs you can afford, especially if you live in a cold climate.
You need to ensure that your cabin is built well with seamless air-tight joints to maximize energy efficiency and stop drafts. If you are only going to do one thing to your walls in terms of insulating, you need to caulk them. Caulking is a flexible sealant used to seal in between the logs; you can read more about the process of caulkinghere.
Due to the nature of logs, they expand and contract throughout the year; in the winter, logs will expand, and in the summer month they will contract. They are still likely to do this even if they have been kiln-dried.
With this in mind, your log cabin can vary in height throughout the year quite considerably so if you were to fix the studding and cladding to the walls to add insulation to them, you would restrict the natural movement; this could result in gaps appearing in your walls and therefore make it less energy efficient.
If you have used thick enough logs you probably will not need to insulate your walls any further, however, some companies do offer wall insulation in the form of either a sliding bracket system that doesn’t restrict the log movement or a twin skin wall with insulation in between.
I would not recommend a twin skin wall due to the nature of the logs shrinking and expanding; having two walls rigidly fixed together is a recipe for disaster!
The two areas I would absolutely recommend insulating are your floor and roof.
Floor Insulation
Approximately 70% of heat escapes through the floor and roof, so it is, therefore, essential to insulate them well.
Insulating your log cabin’s floor can save up to 20% of your annual heating costs when fitted properly and combined with the finished floor.
First steps first, you should install a moisture-resistant membrane such as Tyvek, this will prevent dampness from rising and keep the underneath of your cabin dry as it acts to stop water coming through but allows water vapor to escape.
Once your membrane is in place, you will need to lay thin pieces of wood to raise your log home off the ground. If your log cabin is already raised off the ground slightly or is on stilts, you will still need a moisture-resistant membrane and you can continue with the steps below.
Secure your joists onto the lathing and attach batons to the joists to support the insulation. When attaching the batons, keep in mind that you will need to leave around a 50mm gap between the membrane and the start of the insulation to allow airflow to remove moisture.
Joists are horizontal members or beams which run parallel between the foundation to support a load.
Once the membrane and joists are in place, you need to cut the material you are using to insulate to the right size to fit perfectly in the cavities made by the joists.
By making sure the insulation fits snugly, you will avoid cold spots in the flooring.
The top of the insulation should sit flush with the top of the joists, and the flooring should lie directly on top. Your insulation should be at least 50mm deep to work efficiently.
Log cabin roof
If you want to insulate the inside of your roof you need to flip the process round for insulating the floor.
Most people who build a log cabin will want the beautiful detail of the high roof and rafters to be visible from the inside, unlike many regular buildings when the ceiling is boarded up flat to form a box-shaped room.
It is for this reason that many log cabins will have insulation on top. Your log cabin should be completed to roof rafter level and the roof should then be sheathed with your boards; I would recommend using good quality aged boards rather than plywood to add to the rustic feeling of your cabin.
You will then need to cover your roof with moisture-resistant membranes such as the Tyvek or Kingspan as mentioned before. You will need to staple your membrane down onto the boards. This is great because it will stop the warm cabin air from escaping into the layer of insulation.
It is then time to add your insulation and there are a great many to choose from. If you are sticking with sheets, you will need to add batons to your roof to encase the insulation.
Your batons will need to be put around the edge of your roof and spaced out evenly along the length of your roof. You can then cut your insulation to size to fit in between. Similar to your floor, you should leave a small airflow gap so make sure your insulation doesn’t sit flush with the very top of the rafters.
After this step, your roof is ready to finish as desired; there are a great many options to finish your roof.
Insulating materials
There are many different types of insulation you can use, from manmade materials like Kingspan and Celotex to natural materials such as recycled wood fiber or sheep’s wool.
This will depend on your budget and the resources available to you in your area and personal preferences.
Log cabin Double Glazing
You may also want to consider having double glazing to maximize your energy efficiency.
If you’re building in a cold climate you definitely use logs that have a diameter of at least 10 inches, however, if you are building in Europe or a warmer climate, your logs may not necessarily be as large depending on the purpose of your log cabin.
Double glazing is only worth getting in lob cabins that have walls with logs of a diameter of at least 58mm.
Any less than that and the walls are actually not as effective at insulating as the windows, in other words, more heat will escape through the walls than the windows.
See the values below to make more sense of this:
| Material | R Value | U Value |
| Single pane of glass | 0.94 | 1.10 |
| Double pane of glass | 1.93 | 0.52 |
| 28mm Spruce Logs | 0.29 | 3.42 |
| 45 mm Spruce Logs | 0.45 | 2.21 |
| 58mm Spruce Logs | 0.61 | 1.64 |
As you can see, you will only start noticing the benefits if your logs are thicker than 58mm – this will not even enter in the question for cabins being built in a cold climate as the logs should be much thicker than that.
So there you have it, don’t underestimate the importance of insulation if you are planning on having an energy-efficient log home that is liveable all year round.
You should give this thorough thought during your planning and design process and remember that the two most important areas to insulate are the floor and the roof.
Couple this with well-built, air-tight walls and double glazing and you’ll have a log home that will be able to maintain a good temperature inside all year round.
What is your reason for reading through our article today? Are you just about to start planning your log cabin insulation, or are you looking for a way to make your current log cabin more energy efficient? Let us know and drop us a line below!
Hi, we purchased a 30 year old log home and it has no chinking inside. It is winter and we can feel cold air coming through some of the gaps between the logs and some logs have shifted quite a bit. Can we stuff the holes between some of the logs with something or is chinking required at this point?
Thanks a lot,
Evelyn
Hi Evelyn,
You can cover the gaps with other types on insulation yes, but chinking will provide the best finish in my experience.
David
We have purchased a log timber framed home built in 1982. It is located in the Pacific Northwest on the Olympic Pennisula in Kingston Washington.
My concern is that with the high ceilings and no additional insulation, this will be a monster to heat and cool. I would like some info on how to insulate the roof frtom the inside, as the previous owner recently replaced the metal roof.
Hi Kristine,
It would be really helpful to see pictures before advising you on this. Please send them to david@logcabihub.com
It all depends on whether you want to leave the logs exposed.
Thanks, David
Merry Christmas. We just bought a cabin in Alabama. It was built in 1986, The first thing we noticed was the ceiling and flooring of the second floor is only 6″ X 1″ with gaps between the slats. I know heat is flowing upstairs which is costly. After it warms a bit we plan on caulking and chinking the cracks and joints on the outside. We will check the ducts for leakage as well.
We do have double paned windows and doors. I have not checked the roof yet.
What is the best way to insulat the fooring of the 2nd floor?
Hi Curtis,
There is little if not, no, benefits to insulating between floors other than for sound reasons. You might consider re-doing the first floor to ensure there are no gaps and therefore reducing the amount of heat lost to the second floor.
David
Hello,
My husband and I purchased a log home with a brick basement in North Canada.
We have winters of -40C.
The logs are about 10” and need some work as there is some rot in some of the bottom logs which I will be cleaning out and filling in.
The home has never been chinked (we are doing that this summer)
And whoever had it before insulated with R20 between wood studs, then drywall.
This prevents us from chinking the inside.
With the walls chinked outside, should we leave the drywall and insulation and not worry about the inside?
It costs us $1000/m for heat.
I hear it should be much less.
Do you have any other recommendations for saving heatin costs?
Thank you
Sounds like you are certainly on the right track Natalie! Well done
We bought a two story log home last year. It has 10 inch flat sided logs and dual pane windows. The west side has large plate glass windows with trapezoid windiws above. It sits on a concrrte foundation with about a 4 foot crawl space. There is no insulation on the underside of the tile floors. Would you still recommend we follow these directions for insulating the floors? Our winters can get to 10-20 degrees or colder occassionally. Thank you for any advice.
Hi have just purchased a log cabin for delivery next month. I wish to insulate the floor & ceiling what base would you recommend? I want to if possible place cellotex inbetween the joists however the sales assistant said They would install it & I would have to lay it on top of the floorboards and fit a second flooring such as laminate . Is this Correct as it seems to contradict everything I have read and makes me question my decision to pay for their installation. Please help
Hi Mary, this does sounds strange. Just one lot of insulation, a sub floor and the final flooring is the usual practice. Thanks, David
This is a great site thanks. My question is our log builder neglected to fit P gasket around the last log join. I want him to remove the roof and fit the gasket because he lied and said it was present. My question is are there any other solutions that will solve this issue. Expanding foam the gap and backer rod and chink the margin perhaps.
We live in the Highlands of Scotland. Thanks 🙂
Hi David, sorry you’ve experienced this. Short of the suggestions that you’ve already made, I can’t think of any other options. Hope you manage to resolve this. Thanks, David
What would be the best way to insulate a new construction roof for a log cabin in WI? We want the beams to show, then carsiding above that. So the insulation would be above the car siding and below the steal roofing.
Hi Mitchell, thank you for your question. The most efficient insulation comes from either PIR board or a closed cell spray foam like polyurethane which, to meet roofing recommendations of R-value 35-45, will need to be 5-8 inches thick. The infographic on this page is helpful. If you have a much deeper gap to work with, then you could use a less expensive and more eco-friendly insulation like cellulose. Check the actual R-value of the material and specific brand you decide to go with and make sure it’s thick enough to hit R-35 as a minimum. Finally, ensure there are no gaps in the insulation, or it’s a waste of your money. Thanks, David.
How do we insulate a 2-storey cabin on studs already built with drywalling.. Not insulated
Hi Jenny, thank you for your question. The easiest methods will be injected foam or blown-in cellulose. Either way, you will need to create some holes in the walls and patch them up later, but it will be far less work than ripping whole drywall panels off. Thanks, David.
I live in a log cabin with foam insulation applied to the gaps outside and chinking inside. Is there a reason for the use of these different materials?
Hi Cherry, that is unusual. Not so much the chinking on the interior – that’s an aesthetic choice, more the insulation foam that was probably a cheaper and easier solution at the time than chinking, but I can’t see it lasting nearly as long. Keep an eye out for and holes that form in the foam! Thanks, David.
We recently purchased an Amish built log cabin. I plan on using it for my art studio. Living in Indiana, our winters are unpredictable and summers quite humid.
I want to keep the rustic charm inside but how do I insulate the ceiling/roof and floor without covering up the raw wood? I DO plan on using a vinyl flooring with an underlay material but there is no insulation underneath. It is on runners, but not high enough to crawl under to insulate. The ceiling rafters are 2×4’s, is it better to insulate from the outside, inside or both?
Thank you very much for any recommendations you have!
Hi Bobbie, if the internal rustic charm is your ultimate goal then insulating the roof from the outside is the way forward. Only one insulation, internal or external, is needed. Personally, I prefer internal, but we all have our priorities! For the floor, would a spray application foam work? David.
I purchased a rustic cabin in May. There are lots spaces between the woods. The roof is metal roof. The floor is woid floor. We are living in Muskoka Canada noe the temperature is just above freezing.
We are thinking to insulate the walls with the starfoam from inside. However after reading your article, it seems no need. Can you let me how what is yhe correct solutions to winterize the rustc cabin?
Thanks
Jennifer
Hi, Jennifer. Apologies for the delay in responding, I’ve been on a long vacation; I hope you’ve found a solution by now as the temperatures have dropped a few degrees since. When you say there are gaps in the wood, do you mean gaps that air can flow through? If the roof and floor are well insulated, but there are actual gaps in the structure then your first job should be to fix those gaps up with chinking. If the cabin is well sealed, then just the roof and floor will be fine. Warm regards, David.
Hi love your video , it answered many of my questions except for one, I plan on buying my forever cabin to live in when I retire, near Delta CO. Very cold in winter especially with the north winds. This cabin is two stories with cathedral ceilings, how do I insulate the log walls? They are very thick 15″ diameter at least and very beautiful. The ceiling is exposed and there is composite shingles on the roof. How do I insulate? I do believe there is a crawl space. Floors have not been finished which is good! Thanks, Dave
Hi Dave, For the floors, if they haven’t been finished yet, I recommend insulating between the floor joists with insulation batts. This helps prevent heat loss through the floor and keeps the interior temperature more consistent.
As for the roof, adding insulation in the form of a layer of rock wool or other suitable insulant material can significantly improve thermal performance. This insulation layer is typically installed between the roof rafters or trusses, underneath the composite shingles. It helps prevent heat from escaping through the roof and minimizes the impact of cold winds.
Considering the specific climatic conditions in Delta, insulating your cabin properly will make a significant difference in maintaining a cozy and energy-efficient living space.
We purchased a thirteen year old log home in Northern Vermont in 2017. The house is about 1800 square ft, The logs are made of cedar, are about 7” thick, and are not chinked. The house sits on a full walk out basement, which is insulated. We have in floor radiant heat on the main floor, but heating the main level has been a challenge. We can see gaps between the logs in many areas that allow drafts to enter during winter months. There is insulation in the roof, but the extent of it is unknown. We are using on average 250 gal of heating oil, and 3000 KW of electricity every month during winter. Is it possible to insulate the exterior walls from the inside? I have thought about building stud walls inside the exterior walls and applying rigid foam insulation. Is this possible? If so, should there be some sort of vapor barrier applied? Should I leave an air gap? I would cover the inside of the insulation with drywall. Does any of this make sense? Any advice that you can offer is greatly appreciated!
Thanks,
Tim
Thank you for reaching out and sharing your concerns about your log home in Northern Vermont. I’ll do my best to provide some advice and guidance.
Firstly, I recommend checking out my blog post on log home maintenance, as it may offer valuable insights on how to address issues with drafts and gaps between logs. Additionally, you should also take a look at the blog post specifically about chinking, as that may be a necessary step to seal the gaps effectively.
Regarding insulation, it is possible to insulate the exterior walls from the inside. This can help improve the insulation of your home. However, it’s important to consider that by doing this, you may lose some of the thermal mass and inertia provided by the log walls.
To insulate the walls from the inside, you can follow these general steps:
Install the stud walls with the appropriate spacing and secure them to the existing log walls, leave a gap between log wall and stud wall to allow for air circulation and moisture management..
Apply insulation within the stud cavities, It can be rockwool, glass wool, etc…
Install a vapor barrier on the warm side of the insulation to prevent moisture buildup.
Cover the insulation and stud walls with drywall for a finished look.
It’s essential to pay attention to how your roof is insulated as well. Make sure there is adequate insulation in the roof to prevent heat loss. Additionally, check the condition and effectiveness of your windows, as they can significantly impact energy efficiency.
While insulating the walls from the inside can help improve energy efficiency, it’s important to weigh the trade-offs and consider the impact on the overall thermal performance and aesthetic appeal of your log home.
I hope this advice provides you with some helpful direction. If you have any further questions or need more specific guidance, feel free to reach out. Best of luck with your log home improvements!
Just bought a cedar sided home in the pikes peak area. Found out that the house is a cedar wood cabin and not cedar sided (there is no insulation between an interior or exterior wall, it’s just the cedar wood ~6 inch thick). Roof is metal with tongue and groove cedar cathedral ceiling in the loft. Basement below is unfinished. How to best insulate for 10 degrees or lower once winter hits. We have a wood stove and one natural gas furnance on main level but worried about keeping the heat in.
Congratulations on your new cedar wood cabin in the Pikes Peak area! I understand your concerns about insulation and keeping the heat in during the colder months. Here are a few recommendations to consider:
Start with general maintenance: Before addressing insulation, it’s important to ensure your cabin is well-maintained. Check for any gaps or cracks in the cedar wood and consider chinking the cabin to seal these areas. This will help reduce drafts and heat loss.
Finish and insulate the basement: Since your basement is unfinished, it presents an opportunity to improve insulation. Insulating the basement can help prevent heat loss from the ground and keep your home warmer.
Evaluate the roof insulation: Take a closer look at the insulation in your metal roof. Adequate roof insulation can significantly impact the energy efficiency of your home. Ensure there is sufficient insulation in the roof space to help retain heat.
Consider adding additional insulation: If needed, you can explore options for adding insulation to the interior walls of your cabin. One approach could be installing stud walls and filling the cavities with insulation material. This can help enhance the overall insulation and thermal performance of your home. However, keep in mind that this may alter the aesthetics and character of your cedar wood cabin.
It’s also worth mentioning that proper air sealing and weatherstripping around doors and windows can help prevent drafts and improve energy efficiency.
I recommend consulting with a local contractor or insulation specialist who has experience working with log cabins. They can provide tailored advice based on the specific characteristics of your home and the local climate.
Best of luck with your insulation efforts, and may you enjoy a cozy and warm winter in your new cedar wood cabin!
At the same time, many antique