Log home needs help

I own a 2 story log home in central TX. The house was built in the 80s, likely a log home kit. Our biggest issue is lack of insulation.  I’m trying to figure out a method to insulate the exterior, as I would lose a lot of space trying to insulate from the inside. I’ve discussed this on some log home forums but the replies are usually coming from folks in more temperate climates. I really don’t think a log home is a good idea for central Texas. When it’s 100+ during the day and upper 90s at night, for days on end, the logs just soak up heat. We are in a very humid area so this needs to be considered. Any thoughts.

First, i preface this with 'I hate log homes!" I have lived in 3, and I hate log homes. IMO there is a reason they were the first homes people built historically, then they upgraded to a 'real' house. That being said, they are pretty.

I would be very wary of insulating a log home because of the potential for moisture issues. Can't think of how to do it, so won't make any speculation. If I was going to insulate the outside, I think you might end up basically building a shell around the house, which seems pretty cost inefficient.

Have you considered using passive cooling? For example, switching from a dark roof to a white roof, perhaps a translucent whitewash on the outer logs to reflect heat? Also, how's the ceiling insulation and attic venting? I have lived in 2 upper story loghouse bedrooms. One had excellent ceiling insulation and was mostly tolerable in sweltering weather without AC. The other was 'die of heat stroke' heat all summer, with poor ceiling insulation.

I’m not a fan of the log home, but it’s what I have. Yes I imagine I will have to build a “shell” around the house, but how. I posted this in the natural building forum on purpose. I know I can insulate with a vapor barrier then poly board, then siding. How can I do the same naturally. I suppose letting y’all know what materials are available could help. We have plenty of cedar that can be cut, our soil is a lot of sand on top of thick clay. Straw is not available at a reasonable cost in the area, but maybe there’s an alternative? My thoughts so far on a natural method would be to essentially build a cob house around the existing log home but I think that would cause moisture issues between the log and cob.

If you're thinking about building a cob house around the outside of your current house, I would say just build another house. Then you'll have 2.  Otherwise, you have a really big, hard-to-build cob house with much less room inside.

I think the passive cooling suggestions are good too - whitewash, reflective roof, etc.  

Can you do vegetation solutions?  Plant trees, vines, etc to keep the sun off the house. (but think about fire danger also)

When I was living in a yurt - zero insulation - in the super hot months I got a gigantic tarp and strung it up in the trees around the yurt - creating a shade spot.   Maybe think about a summertime shade set up, rather than building a 2nd house.  Even if you had to have telephone pole sized poles set up and in concrete around your house for the shade tarp to hang from, it'd be cheaper and easier than building a 2nd house.

Are the windows in this log home original 1980's windows? If they are, then I suspect that solar gain is warming the interior of the log home much more than heat radiated from the thermal mass of the logs themselves. One option, aside from replacing the windows with modern double pane inert gas filled windows, is to tint the current windows with a window film. I don't imply to darken them like automobile window tints, but to consider clear window tints made for homes, and they block the infrared wavelengths of sunlight which have a great effect on warming the interior of a house. This sort of window film is popular in southern climes such as Texas where winters tend to be mild and short, and the need for winter solar gain isn't as important as say living in Vermont. If you do look into replacing the windows, modern windows now often come with a coating on the glass which blocks infrared, so no need to use a window film.