Timber Framers Guild Forums General Straw Bales & Other Enclosure Systems A Proposed Simple Timber Frame Wall System

In trying at all costs to avoid an outboard frame enclosing my timber frame, I've been thinking about the following system (which I'm sure is nothing new but a search didn't bring up any posts specifically addressing this idea).

From outside to inside:

* board and batten siding
* 1x horizontal nailers
* sheathing directly on timber frame and studs (some timber studs and and some 2x studs)
* wall cavities between timbers and studs receive blown in or damp spray cellulose (to 6" or so)
* lath
* lime plaster flush with interior face of timber frame

I can see some issues perhaps arising with timber shrinkage affecting the interface between timber and exterior sheathing, as well as interface between timber and lime plaster. Any other issues that should be obvious to me but aren't at the moment that should really concern me? Thanks,

Miles

Construct a hybrid. Meet them in the middle. Build the stud wall flush with the exterior of the frame, board it over and apply a thermal layer over the boards, 2" of foam, which you strap and side giving an air space for the boarding to dry. This will give the thermal brake and tighten the envelope some, even after the frame and other material has shrunk. You have to give some to take some.

Tim

Thanks for the input Tim. I should have mentioned one reason I'm trying to keep the wall system in one plane is so that everything can sit atop a 10" poured concrete wall. Another reason is just to cut down on material, although the wall system you describe doesn't add too much more to the mix. And yet another reason is that I like the look of timber and plaster walls much more than the look of the timber frame standing alone inside the building space.

I realize that the timber/plaster interface requires repointing with plaster as timbers move and shrink.

I can see how the wall system I described in the first post might not make for the tightest house in terms of air infiltration. The thing is, here in the hot humid South my main concern is keeping the house cool, rather than trying to keep out our comparatively mild 8 week winters :-). As such, putting time and energy into a "cool roof" system seems more important than building a super tight envelope. At least that's how I'm thinking about the building design at this stage.

Miles

The climate in which you live can have an impact on how the wall system is constructed, for sure. Perhaps it is not such an issue, but in colder climates it is.

knowing your location, in the southern part of the country would influence my opinion. On the surface I see no problems with the system you have outlined. Perhaps someone from the south will add to it.

What type of plaster are you planning on using?

Tim

For plaster I was planning on slaking some lime and making plaster according to the recipes in "Building With Lime". There are several limestone quarries and lime manufacturing plants within 45 minutes drive. They sell 1 ton super sacks of quicklime for around $200 (I think).

Howdy,

Miles, I would love to see pictures of the process and hear your feedback. Methinks a lot of other people around here would as well.

As far as the heat in the South..

Well, I was broken by my mother who would not turn on the AC until the mercury hit 95 F. We got pretty good at creating wind tunnels with certain doors and windows open.

And then a nice deciduous tree to the southern exposure would help as well.

Keep us posted please.

p.s. you too Tim!

I am working on it. We now have a flip video camera. Photos are old school. I just have to become familiar with the new school, the kids are helping.

I had some lime shipped to me from Virginia Lime Works, shipping cost more than the lime. I need to perfect my clam shell method.

Tim

I really like the sound of that wall, and I like the look of the timbers with the plaster coming up to it as the inside finish.

I'd like to come up with a way to keep the air infiltration down, personally. I live in a drafty old farmhouse now, and when I build a new one, I'd like it to be a little tighter (and so would my wife). I suppose the biggest problem areas would be at the timber/plaster interface.

I'm also thinking about having 18" or so tall dwarf walls and a timber sill on top of that. And hopefully an earth floor with radiant heat in it.

You could hold the plaster back 3/4" or so from the face of the timbers to add some visual interest. You could have the baseboard die into the corner posts... You could hold the braces to the inside face if you wanted to see them... nice curvy braces...hmmmmm.

I have to think about this some more. How hard is it to learn how to plaster?

Hi Gabel,

I recall an article in Joiners Quarterly about 10+ years ago that illustrated this technique being used at Fox Maple, Browneville, Maine and so maybe Steve Chappell could provide us with a an update on the short to medium term performance of adopting this approach.

Anybody know Steve ?

Regards

Ken Hume

Ken Hume

I attended a workshop at Fox Maple, Brad bb did also. I worked on one of the frames he has in his compound, the dormitory. One of the aspects he implemented was to rout a channel on the timbers side facing the infill, this acted as a key for the infill and to assist in stopping air flow after drying occurred. At least that was the plan when I was there. From my little knowledge of Steve C. I suspect that plan could change or may not have.

The key would also direct the checking of the timber to an unseen face.

Tim