Recently a reader asked a question about chinking a hand hewn log home:
Am trying to figure out what is best to seal between logs [our log home is 100+ yrs. old.]. Most important consideration is keeping rodents out. .. Am sealing from the inside because clapboards are still outside. How can I apply mortar without it dripping out? .. Will Permachink keep rodents out?
Sounds like a great project Brian…
I dont know how large your logs are — but lets assume that they are anywhere from 8″ to 10″ tall by about 6″ thick. The gap between the logs may be about 8 ” on average as well.
Traditionally the space would be filled with a mixture of rocks and mud or rocks and mortar.
Here is what I suggest. First off check out a few articles on here. The first is Simulating a Chinked Log Wall. That might give you some basic ideas as to approach. The second article is Hand Hewn Log Home Chinking and the third is Log Home Chinking and a Chinking Recipe.
Each of those articles will give you a bit of information. The recipe article will give you three different consistencies. You will need to use a fairly dry mixture so that it does not just fall back out — think of it as a thick cake icing.
Here is a diagram as to an approach. (please excuse my crude drawing) First off depending on the size of the home you may go through a
great deal of synthetic chinking — as you are covering a large area — and that could get rather expensive.
Synthetic chinking will remain somewhat flexible and you can poke a tool through it after it has dried — it is very rubbery feeling material when dry. Can rodents get through it? — I guess it is possible that they could dig through it but highly unlikely. — When using synthetic chinking you are only using a thin layer of the stuff if you are following the directions properly – behind the chinking would use an insulating strip called backer rod or some other insulation of your liking.
The synthetic chinking sticks to the wood or finish and not the insulation (backer rod)- so dont be alarmed if you are not getting adhesion to the insulation.
My suggestion is a layer of stiff mortar chinking against the outer side (this would act as an exterior barrier behind the clapboard for both weather and rodents. Then a layer of insulation. And then on the inside another layer of chinking. Figure you an inch and a half of each.
As a strengthening method you could use a wire mesh between the logs which will act as a backing for the chinking to grab helping to hold it in place while it dries.
I’m pretty certain rodents will not be able to chew through real chinking. (chuckle)
There are many 100+ year old hand hewn log homes that have the original chinking mixed with stone between the logs.
I hope that this helps!
{ 2 comments… read them below or add one }
I have just found this website and much useful information – thank you!
I’m not sure I am posting a question in the right place but the only place I could find to send an email.
I am getting ready to side the outside of our home w/ featherboard that I will be cutting on my sawmill. I will be using your recipe for chinking and methods you have suggested. I am wondering what you suggest for the thickness of the boards? The wideness varies between 8-12 in. I will be using western red cedar. Do you suggest apply a proctective coat before putting the boards up? I wondered if the chinking would adhere to the edges if it had been sealed. What do you suggest using? Do you recommend using nail or screws to apply the boards to the wall?
I appologize if these questions are duplicates. I have read thru your blog and didn’t find the answers. Thank you for any advice you have and for such an informative site.
Thank you Jon – I’m glad that you have been able to find useful information on here.
I love feather-board – It is beautiful indeed and not seen often – that you are cutting it yourself if fantastic.
As far as the thickness of the boards – jeeze I am not exactly sure – if cut too thin you may have a situation with cracking. If too thick that could be wasteful. SO you are using the feather-board basically to simulate a chinked log wall rather than using it like traditional lap or clap board siding. let me see what I can come up with and then ll update this response.
I would probably treat or seal the boards first simply as I would find it easier but you may find it easier to get them up and then treat. Mortar chinking does not adhere to the wood but rather you will be using either nails or a mesh that the chinking would grab between the boards.
If you are planning to use a synthetic chinking – which may be (dare I say it) appropriate in this situation I would would recommend chinking materials from the Weatherall Company over all others. In case you choose to use a synthetic chinking – then you will need to apply your finish (check out UV Guard – also by Weatherall, before you apply the chinking. Synthetic chinking material does not adhere to the wood but rather the finish.
No apologies these are great quetions…
I would also advise you to use a 10% solution of water and a borate-based product such as Penetreat to help protect against wood boring insects. It can be applied with a sprayer.
Update: Check out this article on Simulating a Chinked Log Wall.