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Post by wrightwoodwork on Jul 13, 2015 17:39:10 GMT -5
Must admit I'd never given any thought to what you said originally about chamfered edges or square edges before then. Yet thinking about it makes perfect sense as you always see a square timber burned first at the square corner
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ross
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Post by ross on Jul 14, 2015 18:03:04 GMT -5
Just finished the octagonal post. This is to single story wall plate height carrying a beam across the top and a glulam at right angles. An existing 150 year old beam (rotten bit of driftwood in my opinion) is coming in off centre, below the carried beam, this is the socket for that bit;   Final clean up when it's in and the roof's on.
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Post by Red on Jul 14, 2015 18:17:33 GMT -5
Just finished the octagonal post. This is to single story wall plate height carrying a beam across the top and a glulam at right angles. An existing 150 year old beam (rotten bit of driftwood in my opinion) is coming in off centre, below the carried beam, this is the socket for that bit; Final clean up when it's in and the roof's on. You mentioned glulam in your last post, Ross. Are you cutting joinery into it? I was recently asked about cutting joinery into an engineered glulam beam, but I was unable to answer. I've always cut traditional joinery into natural timbers; hence, my inability to answer the question.
If you are cutting joinery into glulam elements of the frame, how are your tools holding up? I noticed in one of your photos that you [seem to] use Japanese chisels. Perhaps you could post in the timber frame chisel section of the forum about your chisel(s).
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ross
Junior Member

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Post by ross on Jul 14, 2015 18:33:28 GMT -5
Hiya Red Still thinking about the glulams as we've no details on how to connect etc. I was going to cut a notch and socket at one end of one, but we're now looking at hidden/blade connectors. To be honest I haven't the faintest idea about how to deal with them  .
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Post by Red on Jul 15, 2015 0:26:18 GMT -5
Hiya Red Still thinking about the glulams as we've no details on how to connect etc. I was going to cut a notch and socket at one end of one, but we're now looking at hidden/blade connectors. To be honest I haven't the faintest idea about how to deal with them  . I'm not sure what they would be called in the UK, Ross, but are you referring to hidden steel spline connections?
If so, you may be looking at a chain mortiser with a long spline cutting bar attached to it. Due to the deep depth and small outer dimensions of the mortises involved, the aforementioned chain mortiser is the only way I've ever seen it done.
Assuming that we're on the same page, a glulam beam connection via steel joinery would render an exceptionally strong connection ... and, as glulam is about as stable as it gets, using steel shouldn't present any rigidity issues.
Is the beam (or beams) unusually long?
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Post by wrightwoodwork on Jul 15, 2015 0:53:37 GMT -5
Another option is to use connection made by knapp not sure which one myself as I don't really do thus type of work. Here is a link they will point you in the right direction
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Post by wrightwoodwork on Jul 15, 2015 0:54:08 GMT -5
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ross
Junior Member

Posts: 52
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Post by ross on Jul 15, 2015 1:08:34 GMT -5
Hiya Red Still thinking about the glulams as we've no details on how to connect etc. I was going to cut a notch and socket at one end of one, but we're now looking at hidden/blade connectors. To be honest I haven't the faintest idea about how to deal with them  . I'm not sure what they would be called in the UK, Ross, but are you referring to hidden steel spline connections?
If so, you may be looking at a chain mortiser with a long spline cutting bar attached to it. Due to the deep depth and small outer dimensions of the mortises involved, the aforementioned chain mortiser is the only way I've ever seen it done.
Assuming that we're on the same page, a glulam beam connection via steel joinery would render an exceptionally strong connection ... and, as glulam is about as stable as it gets, using steel shouldn't present any rigidity issues.
Is the beam (or beams) unusually long?
I'm not sure of the correct term for the connector, Simpson just call it a concealed beam connector.
www.strongtie.co.uk/products/detail/concealed-beam-hanger/481
One beam is approx 4m long, this is the one I was thinking of using the connector for, I'm still scratching my head on how to cut the slot, so thanks for the advice. The other is 8.4m and absolutely massive, the plan is to support that on the gable ends.
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Post by Red on Jul 15, 2015 2:41:45 GMT -5
I hope that my old yank timber framing terms aren't throwing you off. Yes, the "slot" you're referring to is the same "mortise" I was referring to. In my experience, they are typically cut with a chain mortiser equipped with a long/thin guide bar. Apparently, some folks refer to this tool as a "chain slotter." I've included a photo [below] that should give you an idea about what I'm describing herein.
I've never seen the connector shown in the Simpson link, but it's certainly a variation of the steel splines I was referring to. Out in the western part of the US, hidden steel spline connections are often used to join extremely large construction timbers. Although the photo I've included below doesn't show it, these mortisers/slotters are often mounted to the end of a given beam, which allows the bar to be plunged deeply along the long axis of the timber. This particular machine can plunge to a depth of 12-inches (304.8 mm) and render a mortise/slot width of 3/4-inches (19.05 mm).
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ross
Junior Member

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Post by ross on Jul 15, 2015 14:10:03 GMT -5
Red, thanks for the infer on the slot morticer, I'm not sure if one of these can be hired locally and I sure can't afford to buy one new. I'm having a chat with a friend tomorrow who used to import mobile saw mills to see what we can come up with. I may actually go back to my original plan and join the glulam into the post, though it'd be a fairly large mortice  Another day and time to put the sticks together. (please do not think any of my terms are anything like traditional framing terminology in the UK, I am notoriously sloppy and most things end up being called "wotsits"). Two padstones were set up, which are York Stone which'll give a decorative effect and fingers crossed. Due to a few reasons I haven't been able to test fit in situ, not the least of which being the weight of the main post. So the timbers were dry fitted together and are to go into an old existing rubble wall structure. The main post in place;  second post in place;  An original (modified) beam placed back and tied in;  The new wall-plate/beam/wotsit placed in to tie it all together;   I'm a bit unhappy that the main post is a touch off vertical, but not too bad for the constraints imposed, Here's the join for the old beam to new;  just waiting for a bit of tidying up.
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Post by Red on Jul 16, 2015 10:47:33 GMT -5
That's a good looking job, Ross! Using stone under the posts, as opposed to concrete, is exactly the way I was taught to do it.
Is the octagonal post strictly a decorative effect or, conversely, will it bear more of a load?
What type of roof will you build between the existing structures?
By the way, where did you get the idea for the Japanese style natural beam?
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ross
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Posts: 52
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Post by ross on Jul 16, 2015 11:34:53 GMT -5
That's a good looking job, Ross! Using stone under the posts, as opposed to concrete, is exactly the way I was taught to do it.
Is the octagonal post strictly a decorative effect or, conversely, will it bear more of a load?
What type of roof will you build between the existing structures?
By the way, where did you get the idea for the Japanese style natural beam? The octagonal post is probably a lot bigger than needed, but we went for this size (12"x12") mainly to pick up the 3 beams which had different heights, depths and positions. It'll be bearing two beams for one side each of two roofs, so does have a fair load. Initially it was going to be a brick pillar. All the oak is structural but mainly being used for some decorative effect. The new building will be very plain so we think it's nice to have some traditional joinery in there, particularly as it picks up the timber framing theme from the old main house. It's also honest and not pretending to be something it isn't. The roof is a standard tiled pitched rafter roof coming end on to the old building in what was the existing off-shot kitchen, with a pitched roof at right angles joining in to it with a small flat roof between it and the old building. It will be hidden softwood rafters but two oak king-post trusses will be in this. I'm going to use wedged through tenons at the bottom of the post. These are the ones where the engineer says we have to use steel, not oak pegs. The natural beam was actually already in the old building in the same place. It was put in somewhere between 1850 and 1996. I'm fairly sure it was salvaged from an earlier build (barn?) as I found a cut-off tenon in a mortice in it, plus a couple of pegs in random places. The main house has various timber framed elements inside and some of the most bizarre joinery I've ever seen. All the wood has considerable beetle damage. The natural beam has had up to 2 inch depth of worm-eaten timber chopped out whilst I worked on it.
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Post by Red on Jul 17, 2015 1:49:49 GMT -5
So what I'm seeing in my head are King Post Trusses with a long through tenons at the bottom of the king posts. To tighten up the tie beams, the struts and the rafters, you're employing tapered oak wedges that will be tightened with a mallet ... and your "engineer" has a problem with this?
Other than the visual appeal preference of a "pendant" style through mortise, I don't think there's anything unusual about the king post truss design you're describing, assuming that my understanding is correct. In fact, the "king" configuration is my truss of choice. They simply don't get much stronger than that.
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ross
Junior Member

Posts: 52
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Post by ross on Jul 19, 2015 17:48:07 GMT -5
So what I'm seeing in my head are King Post Trusses with a long through tenons at the bottom of the king posts. To tighten up the tie beams, the struts and the rafters, you're employing tapered oak wedges that will be tightened with a mallet ... and your "engineer" has a problem with this? Other than the visual appeal preference of a "pendant" style through mortise, I don't think there's anything unusual about the king post truss design you're describing, assuming that my understanding is correct. In fact, the "king" configuration is my truss of choice. They simply don't get much stronger than that. Yep you've got that right. Generally around our way, the bottom joint of the king post truss is secured by a black-smithed strap so the "through joint" would likely be metal, at least for the past couple of hundred years. I just like the idea of a through tenon, wedged. The "principal rafter" part of the truss is likely to be white softwood and I'm not sure how it'll take oak pegs so am thinking of how best to joint these. Additionally, as the tie-beam is sitting on the wall plates I'm wondering how best to secure them down.
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