Combining log and conventional construction

[scgargoyle]

In planning our future home, we thought a log living room would be nice, w/ the rest of the house stick framing. How do you connect the different construction methods to allow for log settling? My uncle's house is part log, but the log part was 70 years old by the time it was added on to. What happens when the logs settle and the adjacent building doesn't? I've wondered what happens w/ interior walls as well.

[thurlow]

Friend of mine across the county is doing exactly what you're proposing.  They went acrost the river into Missouri and bought the remains of a log cabin built about 1850.  The part they're using is only about 12 x 12 or so.  I assumed the logs were either yellow poplar or chesnut, but he said they were cypress.  We looked at it this past Sunday; they're about 6 or 8 weeks from completion.  I'll ask him.........next time I see him.........how they did it.  Will carry my camera next time and post a couple of pictures.

[beenthere]

I suspect you will need a slip joint between the two constructions. Even if the logs are "dry", there will be seasonal movement vertically, compared to no movement vertically in the conventional wall (studs are standing and don't change in dimension along the grain, for all practical purposes).  So it seems to me. 

[Stephen1]

there is a lot of info out there on settling of log walls and the joining of the logs to stick framing. Simply put a spline  attached to the frame and inserted in the logs would be used to allow the log walls to slide down. Count on about 6" of shrinkage for the log walls

[scgargoyle]

6"? Really? For KD logs? Wow! I had heard 3/4" per foot, so over 8', that's about right. What happens to interior walls when all this is going on? I guess the interior walls would have to be attached w/ a spline, too.

[Don P]

The walls are only one part of your thinking process, the roof is also a big concern. If you can seperate the log structure's roof from the stick framed roof it will be much easier. The simplest way is to attach to a gable end, dropping the log section's gable under the main roof gable. Then step flashing off the log room's roof against the main house gable wall with a counterflash attached to that wall allows the log roof's steps to drop while still protecting them.

If you are talking milled logs, in over 50 homes over the last 16 years I've never had more than about 1-1/4" settlement in 8'. Well dried milled logs have settled much less. There are ways to get that to zero if you want a chinked look. Piece en piece with corner posts and a header log atop will also accomplish this. The old chinked appalachian log homes did not allow for settlement, the window and door bucks were solidly dowelled to the log ends. Most have settled somewhat in the corners, more than a few have held up pretty well though.

This is a interior wall intersection with a log wall. The "trough" is 6" wide. That allows for a studwall plus 1-1/4" on each side. This allows space to slip in drywall and a 3/4" trim board...makes finishing and painting the drywall easier. The blocks are to maintain that space till the rockers get there. This manufacturer kd's and their manual gives no settlement details. The door buck and header log were precut in the mfgr's plant.  Different manufacturers do different things, I've had 30 sheets of settlement details from one company.

[Norwiscutter]

I will second Don's 1 1/2 inch max for well-dried logs. Even in situations were milled logs with a high moisture content are used, I haven't experienced over 3/8th inch per foot.  Of course my experience thus far is limited to softwoods so I cannot comment on any hardwoods. Scribed logs homes comparatively have a larger amount of settling compared to those that use milled logs.  I tend to question though your desire to have one section of your house log and the rest framed. Not that it can't reasonably be done but I am simply wondering why. Outside of the historic restoration of old hewn structures as additions, I would think that framing it all and using a good log siding would not be more appropriate.

[scgargoyle]

In looking at ideas for our new house, we've had lots of ideas. It will be a small (1200 sq. ft) house, in 7 acres of woods. It will eventually be our retirement home, so I'm trying to plan for that, too. We love the look of a log cabin, and my wife is convinced I can build one, I guess cuz they look like 'lincoln logs'. I'm looking into sips more and more, and the suggestion of log siding is a good one, esp. installed over sips. Is there any way I can make fake corners to look like the real thing, though? I don't care for trimmed corners; I'd rather have dovetailed logs. As far as the interior goes, I can just put up horizontal rough sawn boards, and leave gaps for 'chinking'. If I ever get a mill, I could saw my own interior siding. If my health holds up, I'll probably do much of the construction myself (with helpers). I'll contract out the foundation, and maybe the electrical and plumbing. Around here (FL), they really discourage DIY utilities; it's not worth the hassle they give you. All this is why I had the idea of part log construction. From what I've seen, working w/ milled logs is more expensive than other construction, so I thought just  a log 'great room' would save me some money. I have the skills to do most any type of construction, but time will be a factor, as well as money.