Page 2 of 4 < 1 2 3 4 >
Topic Options
Rate This Topic
#33509 - 02/15/16 07:58 PM Re: Double-Wall Enclosure Concept [Re: D L Bahler]
Jay White Cloud Offline
Member

Registered: 11/06/08
Posts: 484
Loc: Vermont
Originally Posted By: TCB
...Planks set into grooves in the two sets of posts...M&T cross ties...waist-height 'sil'...with loose insulation*...removable vertical plank...plumbing path...foam block...engineered wood flooring is used to form the interior planks...12" thick wall...4ft post span, each post a 4x8...double-roof...support a large overhang (and possibly even a vented roof layer)...


All in all, I love the concept, and it is actually following a design parameter that several Timberwrights (myself included) are starting to explore and/or employ in their designs. Much of it is nothing new and more a "dusting off" of some older vernacular methods from around the globe.

I love "Double Roofs" and can not expand enough on how functional and aesthetically pleasing they are. That was a wonderful choice...

As for insulation, I no longer use "blow ins" as they are to plagued with long term issues and/or do not function as claimed. I prefer and use either natural insulative materials, mass systems like log, plank, stone, cobb, light cobb, adobe, etc. For a "modern insulation" (yet over 150 years in use with excellent results) I employ mineral wool batt and board.

Your design is very much like a "Wall Truss" however I would say more than half of these contemporary wall systems seldom are "hung walls" (though this works well if designed well) and actually rest on foundation of some form...

Wall trusses and your modified timber form of them both lend themselves well to "cold roof" and "rainscreen" modalities as well...

I look forward to watching you develop your concepts.
_________________________
http://about.me/tosatomo

Top
#33529 - 02/16/16 10:38 PM Re: Double-Wall Enclosure Concept [Re: TCB]
TCB Offline
Member

Registered: 02/10/16
Posts: 26
Loc: Texas Hill Country
Thank you both for your thoughts!

D L Bahler;
"First of all, 'Plank and frame' or 'Bohlenwand' techniques are the inferior of the two solid wood infill techniques. The better technique is what I know as 'Fleckwand' which you should think of as a log infill. This technique descends from a hybridization of log and timber building in the sub-alpine regions on the northern verge of the Alps (in contrast to the Bohlenwand or thin plank infill which is simply a timber frame with boards inserted between the framing)"
I can see how this would trend toward a convenient way to stack heavier timbers/logs, but I'm not certain such heavyweight construction would work for me; for a two-story structure far, far away from large-diameter lumber supplies. My plan of attack was actually to see if I could get the exterior layer to be built of staggered Hardieplank (or similar) and the interior of engineered flooring; I'm not sure how realistic these are given the spans they'd be bridging between frames, but the concept of puzzle-piece interior/exterior layers with minimal follow-on finish work is appealing to me.

It's funny you mention the Swiss & large overhangs, since it appears I am rapidly trending toward that sort of design, here. I think I may actually adopt the two-frame solution you described, since as a two-story structure it is somewhat convenient; support the roof on the outer level with a beefy frame and a lightweight interior frame supporting that face of the wall & partitions, but a heavier interior frame on the lower story to carry the floor joists as well as to stabilize the exterior frame structure.

Jay White Cloud
"Even a "light daub" system of say a "Bousillage" type would be far more robust than any modern "drywalls," and if you combine this with adobe methods of the region, (along with the appropriate lime plasters) you have an extremely durable system plastering (inside) and rendering (outside) finishes."
Very interesting. I'd always thought that plaster fell by the wayside for being crack-prone as well as labor-intensive, but perhaps only the latter? Whichever is less hassle to keep up with is my preference (and I wouldn't mind learning to plaster, at least on the room-interior walls & ceilings where it would likely be). At any rate, I'll be focusing on surface finishes more once I get further along.

"I love "Double Roofs" and can not expand enough on how functional and aesthetically pleasing they are. That was a wonderful choice..."
You may think twice about that once I get it fleshed out in the other thread a bit more. Or rather, I may think twice once the time comes to actually start figuring out how to make & assemble everything, lol.

"Foundations in general, in historic architecture, can often present as having more issues than they actually have, and/or suffer from neglect and inappropriate modifications by "ill experienced" over the decades or even centries."
Fair enough; I'm sure a good number of the vintage structures themselves suffer from inappropriate construction methods in the first place, that a properly trained professional now readily-available would be able to avoid. I still like the idea of a concrete 'bathtub' for building partially into a hill, even knowing concrete isn't all that waterproof. I'll be sure to open a thread on the topic once I have more details to discuss.

"For a "modern insulation" (yet over 150 years in use with excellent results) I employ mineral wool batt and board."
I agree the blown stuff is kind of a pain, especially when you actually have to work with it yourself instead of paying 'some other guy' to deal with it. Honestly, it may not even be that good an idea given the lack of positive seals between the posts and the planks; could be leaky. I won't be purposely seeking out sustainable solutions unless they are the best fit for my situation, but I think you're right that a quilted/batt type material --whatever it's made of-- would work a whole lot better than a loose one, and probably be easier to install. Less mess if I have to dig in there to route whatever new utility line is a 'must have' ten years from now, also (this serviceability aspect is part of the reason I am opposed to a solid infill wall system; not sure how one goes about retrofitting a conduit line through a block of cobb or wattle/daub without a whole lot of work)

"Your design is very much like a "Wall Truss" however I would say more than half of these contemporary wall systems seldom are "hung walls" (though this works well if designed well) and actually rest on foundation of some form..."
Interesting, the Larsen-type ones I saw all seemed to be suspended, and I assumed it was to shield the foundation from rain or to ensure ventilation of the more exposed wall frames. Perhaps I can get away with just my overhangs protecting me, here. I've actually been trying to figure out what the best plan is for the floorplate side of these plank walls; I assume you don't want to just have them sitting in a sunken groove in a plate that is some combination of rot-prone or ugly, but a neat trim-based solution isn't jumping to mind readily. Lot of examples in pictures just seem to have boards sitting on the foundation directly, or suspended on sacrificial spacers (presumably some sort of filler material seals the gap internally). Is that really all there is to it? I expected more complexity from the Swiss, lol.

"Wall trusses and your modified timber form of them both lend themselves well to "cold roof" and "rainscreen" modalities as well..."
I've read about cold roofs, but 'rainscreen' is a new term; could you explain? I decided to run with the double-roof once I realized that I could get a thick, insulated roof over the interior areas, but a pretty thin overhanging roof over the outside (to keep the externally-visible roof profile looking thin). One of those design choices that just seems perfect the second you visualize it.

TCB

Top
#33530 - 02/16/16 10:49 PM Re: Double-Wall Enclosure Concept [Re: TCB]
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
TCB,

I think maybe a good fit for the sort of scenario you are looking at would be an industrial revolution era German and Swiss (My research suggests it may have originated in either Bern or Basel, or just across the Rhein is south Germany) sort of light timber framing. For good pictures, go to google.ch (swiss google) and search the term 'Riegelbau' then look up images (it should default to English, but if it doesn't 'Bilder' is the German word for pictures). This is the sort of framing that's most common at least in the Swiss Canton of Bern today, an extraordinarily efficient building system.

I think you could easily adapt this to work with your system without creating tremendous waste and redundancy. Basically two such light frames built together.

Actually you have really got my mind working, and possibly led me to just the answer I have been looking for to build a timber framing system that is super efficient, yet can still incorporate the sorts of features people want to see. I'll have to open up sketchup and play around with some things...
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#33532 - 02/16/16 11:25 PM Re: Double-Wall Enclosure Concept [Re: TCB]
TCB Offline
Member

Registered: 02/10/16
Posts: 26
Loc: Texas Hill Country
"framing system that is super efficient"
Aerospace engineers are really bad about that, actually. Hopefully this concept, unlike aerospace stuff, can actually be built without five mortgages! The types of design goals you mentioned are exactly what I'm going for, so I'm not surprised we're on a wavelength.

Thanks for the tip on 'Riegelbau,' very good stuff there aesthetically as well as structurally, to draw from. Not super sure how to adapt it to an octagonal plan with shallow roof, but I'd like to try. Only thing I don't like is the number of hammer-beam roof gables I keep seeing; they look...difficult.

I also don't know what it is about Bern; this is like the fourth or fifth product from that specific region I've come to admire greatly, despite not having a particular fascination or connection to the place. I should really visit some time, since the place seems to just exude excellence (beer, housing, guns, hand tools, machine tools, the list goes on...)

TCB

Top
#33533 - 02/16/16 11:41 PM Re: Double-Wall Enclosure Concept [Re: TCB]
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
I've seen it done, regarding the octagonal plan.

And roofs can be done any way you want, the concept of this framing is that the framing of the roof and the walls are pretty much independent of each other.

And I'm a product of Bern, so I tend to be biased to the region smile All those things you mention, ya they're kind of a big deal there! You buy me a plane ticket, I'll give you a personal tour! I know all the best spots...

As for framing octagonal designs, it's actually done quite frequently (think castles) Usually, they accomplish this by having a post in the corner that is cut with specially angled faces. But I rather like the idea you show in your other thread of just putting one post either side of the corner and letting the trim job do the rest (though this may be hard if you're doing an infill)

I'll look through my extensive photo gallery (think like 5k pictures) to see if I can find you some octagons.

But regarding super efficient, ya I'm swiss so... I tend to be preoccupied with the concept in a way that is probably annoying to everyone else (why can't you just let things be -because I'm Swiss, dangit!)
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#33534 - 02/16/16 11:48 PM Re: Double-Wall Enclosure Concept [Re: TCB]
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
By the way, I should mention Riegelbau is analogous to the German Fachwerk, which is what most Americans at all familiar with the style of framing would think to use. I use Reigelbau because it's more specific -Fachwerk includes a number of different framing styles and really refers to the fact that a building is half timbered. Riegelbau is a very specific type of framing that bears this name whether it is used for a half-timbered structure, or whether the frame is wrapped.

This is the sort of framing most commonly used in Switzerland today, and interestingly enough is frequently employed in the mountainous regions and given a facade to imitate the log building styles native to the region. (A close examination will usually reveal the counterfeit)

There's my off the topic rant for the day...


Also regarding the heavy timber infill, I wasn't inserting that there in an attempt to persuade you to the idea necessarily, just more as an effort to put things in perspective and shed light on how the techniques are being used right now.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#33559 - 02/24/16 07:54 PM Re: Double-Wall Enclosure Concept [Re: TCB]
TCB Offline
Member

Registered: 02/10/16
Posts: 26
Loc: Texas Hill Country
"As for framing octagonal designs, it's actually done quite frequently (think castles) Usually, they accomplish this by having a post in the corner that is cut with specially angled faces. But I rather like the idea you show in your other thread of just putting one post either side of the corner and letting the trim job do the rest (though this may be hard if you're doing an infill)"
I had kind of figured on placing a T&G 1x12 vertical board on either side of the corners as a sort of sheathing for the closeout. Done cleanly, would even look like larger timber$ smile

Also had a question relating to these corner joints; I had originally planned on the standard practice of running 'lintel' boards (top plate/etc) between the posts over each wall and scarf/lapping them over each other at the corners instead of over a post as is typical. However, I am trying to find a place for my floor joists & inner roof members to sit, ideally also at the post locations. With smaller timbers, is it wise to have two orthogonal members coming into the post at roughly the same elevation, or will the post be too weakened to properly support the upper floor walls?

I had the idea to rest the plate timbers across the uppermost 'cross ties' (appears to also be called 'nogging' if I understand correctly) connecting the inner/outer posts. To me, this seems entirely reasonable provided the ties are sufficiently large since the span is only several inches and the only loads/joints from the other structural members are at the posts, but perhaps building codes disagree? This would have the benefit of also leaving the tops of the plank-grooves in the timbers exposed for installation after the superstructure is installed, rather than during, as well as of course leaving a whole lot more cross-section at the upper portion of the post. Also very simple to cut notches in the top plates at each supporting board to tie the posts across the wall spans securely.

Since the M&T cross ties/nogging pieces will have to sit well below the very ends of the posts, my next thought was the remaining post length extending above could be narrowed to a tennon that runs through the center of the floor joist resting on top of the top plate (between the inner/outer posts) up into the next post above. This would neatly tie the two stories' posts to each other as a sort of splice, while at the same time clamping the floor joist timbers between them onto the top plate. It also makes it easy to run the floor joists clear past the exterior wall to form the structure for the perimeter outdoor walkway I seek.

And on that note; if the cantilever of the floor beams past the wall are great enough to necessitate a cross brace down to the post, is it a good idea to have it coincident with the nogging ties between the post pairs, or is intersecting more than two timbers at a given joint location generally a poor idea? That's kind of been my guiding principle so far, since it makes the joint design a lot easier smile. Putting the thrust of the brace in line with the cross ties would seem to best support the posts against bending, though.



TCB


Edited by TCB (02/24/16 07:55 PM)

Top
#33567 - 03/02/16 07:24 PM Re: Double-Wall Enclosure Concept [Re: TCB]
TCB Offline
Member

Registered: 02/10/16
Posts: 26
Loc: Texas Hill Country
Man, things got really dead around here. I assume winter's breaking and folks are getting back to work? Much better things to do than tool around on a forum, to be sure smile

I've decided to 'start over' on my design file structure --that aforementioned order of operations thing with regards to architectural design was kicking my butt. Turns out you need a real strategy for organizing the hundreds (thousands?) of parts & assemblies that go into a structure if you want to make heads and tails of it as you go along wink. Hopefully I've learned enough from this that I won't have to reboot it a second time. So, I'm recreating most of the same geometry, but broken down into floor level, then wall direction (N/S/E/W/etc). I think it's possible to do the walls as near pre-fab, with each face a complete frame 'bent' so to speak, and this file structure should help coordinate that.

I did have (yet another) question about a framing technique I am thinking of using. If double-roofs are such a great/practical solution, why not a structural double-floor? Floor joists seem to be among the wider (taller) timbers used in a lot of designs in order to get the rigidity us humans desire, but couldn't two layers of vertically-tied smaller members function as a truss & do a better job overall (lighter, stiffer, upper/lower joints could be optimized for tension/bearing loads, easier routing, better insulation/soundproofing)? Might squeak more when walked on, I dunno...

TCB

Top
#33568 - 03/02/16 07:28 PM Re: Double-Wall Enclosure Concept [Re: TCB]
Jay White Cloud Offline
Member

Registered: 11/06/08
Posts: 484
Loc: Vermont
Hi TCB,

I am not sure a double floor (other than in some applications to high plumbing) is as warranted as a double roof. Double roofs have a very long and well established logic and practice in historical application...

As for "floor truss" systems, yes those have merit in some areas and application...though not typical for most domestic timber frame needs/requirements of load...

Regards,

j
_________________________
http://about.me/tosatomo

Top
#33569 - 03/03/16 02:56 PM Re: Double-Wall Enclosure Concept [Re: TCB]
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
TCB,

I've been meaning to respond but I've been very busy.

I'll give a quick run-down of my thoughts.

My first observation is, why worry about making the inner framework in your walls structural? This seems to me to be creating a lot of unnecessary joinery without a whole lot of benefit to the structure. My approach would be simply to make an inner curtain wall and let the outer wall do everything structurally.

With this approach, you could just build an outer wall system of any sort you wish. I'd use a 'Riegelbau' style frame, because I think it's well suited to this application, but I'm also biased. The inner wall then serves only as a means of containing the insulation and providing an attractive interior surface.

Off hand I don't see any great problems with your scheme, other than that it may result in more difficult joinery than you may wish to do. I am attracted to systems that simplify the joinery as much as possible, so judge my remarks in light of that not as abject criticism of your ideas.

Regarding double floors,

You are right that such a system could be more efficient from a materials standpoint. However, I would guess it's a lot more work to do and far less efficient from a labor standpoint. You will just have to choose which of these is more important in your situation.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
Page 2 of 4 < 1 2 3 4 >

Moderator:  Jim Rogers, mdfinc, Paul Freeman 
Newest Members
MitchJ, Skemmett, Ali, ccollier, trouts2
4785 Registered Users