Fastening "logs" to cement floors????

[cc-rider]

I'm still in the design stage for my cabin, but thought about using a couple 20' long logs for supports for my ridgepole. The floor will be a cement pad (because of solar). I'm stumped as to how to mount the log/trees to the cement pad! Any ideas would be appreciated!

If you know of any links to clerestory (sp?) homes, that'd be great, too! I'm still trying to figure out logistics.....like....where the roof line changes, is that a load-bearing wall, etc.?

The cabin will be about 24' wide, 36' deep, not counting sunspace on south.

Chris in NW Ohio

[Jim S.]

Depending on kind of logs, how about a post buillding approach? Use a 10-inch auger post hole digger and dig down 3-4 feet, pour some dry concrete mix in, set your post up in it, fill the rest of the hole around it with dry concrete up to just below grade, tamping it down with a 2x4 as you fill in, then pour water in on top to set the concrete.

Be sure you brace the post at a level position and keep it level during the process.

Your ridge supports will be in, then you form up and pour your slab. Same process as used in pole barns.

Be great to use with good red cedar, locust or osage orange as your posts. In pole barns, they use pressure treated pine, but you'd probably rather use something more aesthetic than that.

Just a thought.

[cc-rider]

I was thinking about cutting down some unusual shaped dead trees. They are WELL dried, and the bark has been gone for years. Has interesting shapes where the limbs had been, etc.

I don't like having to bury them so deep (that means they have to be longer)....would even a foot or two work? Would they rot off? Would the cement slab cause them to rot?

My only other thought was to put some foot-long piece of rebar in the cement pad (or a couple per tree), and then drill out the end of the log, but that'd be pretty hard to do. I've seen pictures of places with log supports, but never any detail as to how they were done.

Thanks for your suggestions!
CC

[Jim S.]

cc, to bury them you must go at least 3 feet. If you use rebar, you are not giving your ridge post any lateral stability, like you would be if you buried the log. You would have to add lateral stability with your wall construction, then. The pole system works fine for pole barns with cedar posts, there are a million of them all over my state.

I would not want to use deadwood as my posts. I would not trust that to support my house, no matter how pretty. You might use deadwood for internal stair supports and railings, etc.

The forces on a structure are pretty amazing. Just wind force is something else, even at 20-30 mph. I'd want it strong.

On the other hand, it is possible to design your house not to have to have a ridge support, if you stack horizontal logs and then just do a conventional rafter style roof to a suspended ridge board that's held in place by the rafters. It all depands on what style roof you are planning and your design needs.

[cc-rider]

It won't be a log house. It is basically a frame construction, but 8" wide walls instead of 4". There will be a loft, and I was thinking of the "trees" as support for the open edge of the loft (instead of ridgepole....I don't think I was thinking straight).

Other option is a celestory-style, and using the "trees" as additional support where the roof-line changes. Do I even NEED additional supports there, if the house is only 24" wide? I was thinking an engineered truss to span that opening under the edge of the loft.

Sigh. Guess I better be hiring an engineer, huh?

CC

[Beeman]

A good sized piece of angle iron bolted to 4 sides of the log and then anchored to the concrete would work.

[DaleK]

You can use a "yoke" under the post, basically a piece of channel iron that will fit around the post or else angle irons welded together with a piece of flat iron to fit the post. Same kind of idea as they use for setting decks on cement blocks only on a bigger scale.

[just_sawing]

Where you plan to have the logs you will need to pour a pad. The typical is 2x2x12" deep. This will give a solid place for the log standing on end and not crack the floor. This should also have a cut so if it moves any it doesn't take the floor south. You do this for chimmies or anything that goes over the floor rating. When you get the walls layied out you will drill a centering hole to match a hole in the log. This is easyier than trying to build to a predetermined hole.

[texican]

I've got some character logs that I plan on using in a manner similar to the one you're suggesting. I plan on having deep footers... ~24" thick and have a one inch threaded bolt extending ~6" above the slab. If I misplace the settings, I can always cut the bolts off.

Or, I'll do like others mentioned. Having the post stabilized by a "L" piece of iron bolted into the slab, and inset/bolted into the post/beam.

I've read where you should have some type of membrane between the cement and the wood, to keep moisture from getting into the wood... something like asphalt shingle material.

[cc-rider]

Originally Posted by texican

I've read where you should have some type of membrane between the cement and the wood, to keep moisture from getting into the wood... something like asphalt shingle material.

I wondered about that. I don't like the idea of anything showing (bolts, angle-iron, etc.) but if I cut something the same as the butt of the log that it could sit on (asphalt shingle or something) and do like you said with a bolt, I'd like that.

I'm still thinking about maybe just sinking it down like the poles, too...... could wrap it with tar paper below grade??

CC

[fantasymaker]

A picture would be worth a 1000 words! OR MORE!

[pheasantplucker]

I think I would use some treated 6x6s as a sill plate or sill log with bolts (countersunk). After that I'd start my first course of logs.

[texican]

Originally Posted by cc-rider

I wondered about that. I don't like the idea of anything showing (bolts, angle-iron, etc.) but if I cut something the same as the butt of the log that it could sit on (asphalt shingle or something) and do like you said with a bolt, I'd like that.

I'm still thinking about maybe just sinking it down like the poles, too...... could wrap it with tar paper below grade??

CC

I'd probably trim/chop off any sapwood, even if it were a rot/insect resistant species like cedar or cypress. If you're building from scratch I'd think about digging down a couple feet, pour a deep pad...~12" thick, and have a frame near the same size, plus ~4" or so on all sides, and pour concrete in the form... of course lots of steel in all of it. Once the concrete slab cures, you'd basically have a hole (sized to your pole) all ready for you're pole. I'd probably soak the end of the log for a couple days in either diesel, or some copper solutions... and then place pole, and then some extra rich concrete around the pole, to solidify the whole shebang.

I've got one 'character log' that I'm trying to figure out how to use in my ongoing home building project.