In a shed with walls made of perpendicular rough wooden boards, is this possible to apply plaster from inside directly on them? The goal is to seal gaps between the boards and isolate/protect the wood. What would be an optimal composition of such plaster? How such plaster will behave in temperatures way below freezing (-25 to -30C / -13to -22 F)?
If it were me i'd be looking at sealing from the outside, does water hit the walls when it rains? are the boards sealed at all? do gaps widen and narrow?
guessing you have extremes of humidity and temps
wood can last a long time on a shed wall if it doesn't stay wet, but each time the temperature goes up or down, each time the humidity increases or dry out the boards will move, swell and shrink and even bow and flex depending on how they are fastened.
classical sealing for boards is usually done with battens, thinner strips of wood that cover the joints of the boards, i generally try and put the nail through the batten into the joint between the boards to catch the horizontal members,or nail the batten to one side or the other for the entire length , that way there is less splitting of the original boards and everything can continue moving but still have a more weathertight joint,
heavier wood (log cabins) are often chinked with mud, but they are not prone to as much movement, and even then there is an ongoing maintenance
Many thanks for your reply, we do have quite a diffrent temperatures in summer and in winter Yes, it rains on the boards, that's why I was thinking about doing that from inside. An idea of battens seems to me now a better one, since as you have said, boards "work" a lot, change their shape and dimensions, not a lot, but still ...
There's a lot of good advice here. I don't know all the particulars and it is sometimes difficult to advise people without more information or actually seeing the project. That said, earthen plaster will work very well on the interior of a wooden wall. Here's the problem, however. If the wood is very smooth it won't stick very well. You will need to create a rough surface for the plaster to stick well. You could make an adhesion coat out of flour paste and sand, which we describe in our book, The Natural Plaster Book. This is painted on the wall and creates a surface to which earthen plaster will stick. That would be my recommendation. Or your could rough up the wood somehow...that is, score it, and create a very rough surface. You do want to be sure that water doesn't leak into the plaster from the outside, as that will be soaked up by the plaster and cause problems. You could mount chicken wire or half-inch hardware cloth on the wood and plaster onto that, too. That would work very well. Good luck. I am teaching a natural plaster workshop at my educational center this year. Check out the schedule at www.evergreeninstitute.org.
Many thanks for your reply Dan,
The wooden boards are rough, so I might experiment with that. Perhaps combining battens on outside and plaster inside is the best choice.
I'd love to attend your workshop, but I live in Europe and I'm afraid this is not an option for me now. I will check your book though.
Next time you might add a photo. You mean wooden boards on the inside like it's done on the outside?
I would remove the stuff, get insulation in and put it on once again, take care when you take it off to not break it.
Plaster on wood does not work because wood moves and is not a good idea as you never enclose wood in such a way (insects and fungi).
Plasterboard, I hate it, we have it in our home and you only look at it and you have a dent in there, and painting it is a pain. With rough wooden boards you can really get a great look, without being all that neat.
Sound advice on many of these posts...really nothing to add accept photos help understand the challenge better.
FYI "Chink" or "Chinking" is actually the stone, brick or wood chunks that are fitted into the space between logs in log architecture or in timber frames the other material is "daubing" or "daub" and is made of cobb, lime, or rarely a paper clay, and amalgamations of each depending on the culture that is applying the modality of use.