Another Noob with questions

[rmawhinney]

Hey guys I have been lurking for awhile now but I am getting pretty close to my build so I figure its time to start asking some of my questions. I will post some drawings soon and would appreciate any criticism and advice you all would have. I am going to be building a 32x42 single story on a slab on grade here in Costal Maine. I will be cutting the trees starting in about a week. My father has a mill here that I have worked in with him for years. He has milled and built cedar log homes for over 30 years. I could very cheaply build one of those. However, I want to build something more efficient. So my questions to start with are basic.

When it comes to milling 8, 10, or 12 foot stock I've seen thousands and thousands of lineal feet. My father had me standing at the end of the planer sorting v-match by 10 years old lol. 8-10 foot D-logs again seen plenty, we used to peel them all by hand (draw knife and a flat head screw driver). When I went off to college Dad got the German Peeler haha. However, when it comes to big timbers for a timber frame I have no experience milling them. 4x6 20 foot pine for second floor ceilings are common for me but this big stuff is all new. Dad's mill has a 5 foot radial blade so it wont be a problem I just want to make sure I saw them right.

So my questions are:

1. Can someone point me in the direction of some good reading on cutting these logs up correctly?

2. We have a large Kiln that I could fit even my longest pieces in. With log homes we would never kiln dry them first that would be a mess. However, a friend of mine is telling me to mill my logs big, kiln dry them, then re-saw them so that when I put them together there wont be any changes. Does that make sense to do? I don't want to saw them two times. But would that be worth it? Or should I not dry them at all? I also plan to plane them.

Sorry for the book to open up with! I appreciate any help you guys could give me!

[danreed76]

Welcome, rmawhinney:

You've definitely picked the right place to start.  I joined the FF as a rookie sawyer and novice timberframer and I can tell you there's tons of true craftsman on here that will throw years of experience on you, and they are great teachers.

As to your first question, there are several great threads on sawing, particularly one that Jim Rogers posted titled "Planning your last cut first" (or something like that; I can't search right now as my connection is SLOOOOW and it locks up my browser). I can tell you that thread kept a lot of my timbers from going into the 2x pile.

Regarding the drying, everything I have read, and most on here seem to agree, you can't really effectively kiln dry large timbers.  Also one of the conventions of timber framing is that as the timbers air dry in the structure, the joints get tighter and the frame stronger.  I believe Mr. Jim says "the greener, the better".

Dan

[Jay C. White Cloud]

Hello RmaWhinney,

Welcome to the FF.  As Danreed76 has said, you will get plenty of support here.  Ask as many questions as you would like, it is the purpose of this place.  Share ideas, ask questions, and go do something with it.  You can feel free to contact me on or offline at any time.  Folks here will really want to see what your doing, as your doing it.  That's part of the fun, following along. 

99% of timber and full log architecture is done green.  The new age stuff that is being pumped out by factories and cnc machines is not this craft.  Most of that stuff has flaws not worth getting into.  Your project will be more of the traditional stuff.

Reading is the easy part.  There are more books than you could imagine and searches on the net will keep you reading for years.  Joining the Timber Framers Guild TFG wouldn't be a bad idea either. You need to pick a style for your frame, (i.e, European, Middle Eastern, Asian, etc  then within that, modern, classical or folk, to name a few, the list goes on,) for your frame, then you can move forward to how you want to do it.

Again, welcome to the FF,

Regards,  jay

[Rooster]

rmawhinney,

Welcome to the forum!!

So,...even though your request for information stems from your desire to learn more about cutting the logs into timbers, an equally important subject to focus on would be frame design. Are you designing it yourself?...or are you using a predetermined set of plans from someone else?  I guess what I am getting at is that until the plans have been finalized the materials list can't be completed and your cut list will be too arbitrary.

One question that I do have is what type of wood/logs will you be using for this build?...you mentioned that you dad has built cedar log homes...are you planning on using cedar?  what type?

And also please remember we really want to see you succeed with this build...and you can add yourself to the growing list of new timber-framers that this forum has helped through education and inspiration.

Rooster

PS  Build some timber saw horses...you'll be glad you did!!!

[rmawhinney]

Thank you guys for the warm welcome! One of the reasons I have read this forum and wanted to join was the kindness evident in the threads read here and its clear you all have a desire to help noobs out which I greatly appreciate.

I read that thread on planning your last cut first and the opening few lines were enough. Just need to make sure my big stuff are all centered around the heart that's no problem. I think I was really over complicating things in my mind.

To answer your questions; I should clarify I am not going to begin milling these timbers for a while yet. I am going to begin logging them in about a week. I will be using mostly white pine and hemlock maybe some spruce. I do have cedar available but I am going to save that for a small log cabin build down the road (hunting cabin or something).

As far as the style I would like to do....I would love to do a traditional frame, I love traditional joinery! The issue there is that I don't have a lot of time and I don't have any experience in cutting a frame like that. I also cannot afford to hire any of the guys around here that do. With that in mind I am leaning towards using steel plates and mechanical fasteners. The plan I have been working on is more of a post and beam with common rafters 4 foot on center rather than say a 4 bent design.

With a short time frame and no experience do you think it makes sense to skip the traditional joinery or am I being a wimp?

I will try to scan my drawings and get them on here today or tomorrow.

[rmawhinney]

Also this will be built along the lines of a PERSIST home. Wrap and strap. I am going to board it in with T&G, then wrap with grace, 5 inches of ISO on the walls and 8 inches on the roof, strap it all, inverse board and batton on the walls and standing seam on the roof.

My reasoning for the common rafter design is mostly because I have no experience rigging and will be doing most of this build by myself.

[Jay C. White Cloud]

Sometimes it may seem less money to go the post and beam route, but after you pay for the correct bracketing for the loads, the hardware to mount it and the tools to do it correctly, you will have spent the same or more, than if you had cut a traditional frame.  I can cut a small Asian style frame 5.4 m x 7.2 m (18' x 24') in a month, that should be about two or three for you being new and doing it with hand tools, if that helps with a time line.

If you are pressed for time, that does effect things no matter what you are building.  I don't no what to say, other than rushing always leads to problems no matter the building type.  Heed Roosters guidance, it's sound.

Do you have Sketchup on you computer, if you get it we can all help there as well.  It is the best current method for lay folk to break into the CAD world, and get a lot done quick. 

Regards,  jay

[rmawhinney]

Yeah rooster I think has me talked into at least attempting to cut the frame I am trying to keep it as simple as possible. I definitely can mill timbers cheaper than buying hardware. I do have sketchup but no idea how you guys make those drawings I am seeing on here.

What I mean by a short time frame is I need to move into this house by October. The frame is the only part I have no experience in so is the only part that I am nervous about.

[danreed76]

When it comes to drawing the joinery, I recommend you download Clark Bremer's tf rubies (Northern Lights timberframing).  He has also produced some amazing youtube video tutorials on drawing timbers and joinery. Once you have the basics down and have played with sketchup a little, it gets much easier.  When you do come up with a shape/timber/joint you're not quite sure how to draw, you can typically find something similar in a sketchup tutorial video (there's probably thousands of them on youtube).

Dan

[Brad_bb]

I would strongly urge that you not cut any wood until you have your design finished, drawings in hand.  The white pine you want to joinery when green(fresh cut).  You may consider kiln drying the hemlock to try to reduce checking, but they also used it green in the old days.  If using oak for braces, you can dry them ahead to reduce shrinkage, but not as nice to cut joinery dry.  You can do it either way.  I'm pre-drying my brace stock.

[rmawhinney]

ok guys I did this in sketchup (my first time using it) This is completely open to criticism. Please look it over and tell me where I am going wrong. I did not draw the joints on this one. Once I get the timbers decided for sure I will start over in sketchup. I attached two files the first one 3A shows a span of 15 feet over my living room. I don't think the 8x10 I have there now in pine could span that so I either have to move up in size get a different type of timber for that span or do something different. The second file 3B is an example of what I was thinking for that problem. Just an idea. Please check these out and let me know what you guys think. Timbers will be mostly pine I have to go do some walking next week to find out for sure on that. Pine will be the weakest timber I have so I am just figuring as though it is all pine. Thanks guys!

[rmawhinney]

So it looks like a good amount of my timbers will probably be spruce. Is spruce a decent lumber for timber framing? I know it weaker than more desirable choices but as I have a ton of it (a lot more than the pine available) I will end up using a good amount of it.

Also do you guys have a detail of a double span rafter?

I cleared out the house lot and road last week now waiting on the frost to start the ground work. I also got to have a great time with my father clearing out the old log roads to get to the timbers on the back of his land. We snow shoed in about a mile. It was neat because he cut those roads nearly thirty years ago when I was hardly crawling! This is going to be a great project. Thanks guys.

[Brad_bb]

Spruce can be used and has been often.  The strength of timbers is dependent on many factors including defects, sizing and more.  The material strength should not be your primary concern.  Once the frame is designed, and the forces at the joints analyzed, you can then size your timbers, using the material properties, to handle the forces.  If a timber needs to be larger to handle the loads, and it's too large for your asthetics, you can change material and size the beam smaller- to a hardwood like oak or others.  Like I said, it all comes down to the force analysis and THEN sizing the piece to handle those forces with an appropriate factor of safety.  Design should include engineering force analysis.  Yes there are framers with a lot of experience that can build something that will be strong enough most of the time, but it's that one time with something is not sized correctly and you start getting failure and expensive repair, that you'll realize spending a little extra on proper engineering analysis would have paid off.

[Jay C. White Cloud]

Hi Rmawhinney,

Your design looks pretty good... ;D.  I would extend the rafters and purlins to create eave and gable extension on the frame, which also tends to strengthen terminus joints. Other than that you have created a nice design in general. 

I'm probably just restating what Brad has said in a different way, but here goes anyway.  I always recommend a novice have there frames checked by a PE.  I have many years under my belt and unless I using a boiler plate, I still have my frames checked by a PE.

Regards,

jay

[rmawhinney]

Yeah I am definitely going to have my plans checked by an engineer.

Jay I have no eave or rake detail because I am going to wrap and strap it. This allows me to board it in and then create a fairly air tight envelope. After the insulation is on I will build the eaves and rakes.

So I am building this frame then boarding it in with 3/4 tongue and groove on the walls and 2x tongue and groove on the roof. I am having a hard time finding good details on how I am going to board in the walls. Almost every frame I find has nothing to nail to between the posts. I can see some horizontal nailers in a few pictures but cant find any good details of that. I am wondering do I just use say 2x6 or 2x8 and notch for them on the exterior side of the post? It seams like that would weaken my posts. So would I instead use say a 3x5 or 4x4 or something and join them via mortise and tennon between the posts? Also I don't see any with a nailer low near the concrete? In the same discussion I am thinking of the different ways to run my wiring in my exterior walls. Any info would be greatly appreciated.

Ross

[Jim_Rogers]

Are your wall boards going to be vertical or horizontal?

Jim Rogers

[rmawhinney]

Jim they will be vertical.

[Jim_Rogers]

There are many ways to add nailers.

Here is a picture showing some of them:



 

The one at the top has to be done while the frame is being raised.
All the others can be done after the frame is up and you slide them in from the outside.

Does that help?

Jim Rogers

[Jay C. White Cloud]

https://forestryforum.com/board/index.php/topic,62392.msg921137.html#msg921137

Hello RmaWhinney,

There is a lot out there if you know where, (and how,) to look.  Above is a link to one here at Forestry Forum. Many different examples of "thermal-mechanical envelopes."  The cutting off of eaves and purlins grew out of the "stress skin," panel industry.  Also wraping building up so they are air tight has led to "building sickness," mold issues, and/or the investment in expensive Air to Air heat/air-conditioning exchange equipment.  You don't want drafts, but air tight is not the solution.

Wall trusses are more time consuming to use, but you save time in running mechanicals and electric, not to mention future changes.  Our average wall is 250 mm (~10") thick, plus breathing wall, and cold roof assemblies.  Some walls are over 600 mm thick (2') for in-wall shelves and cabinetry.

Regards,

jay

[rmawhinney]

Jim thank you very much that was exactly what I was looking for. You don't happen to have any details of common rafters going across a perlin mid span you would be willing to share do you?

Jay thank you for the information. I have done a lot of reading on that topic and was in the insulation / roofing and siding business for quite a while. I also joined greenbuildingtalk and have been in discussion with them for a few months about it. I will definitely take that information into consideration!

[Jim_Rogers]

You don't happen to have any details of common rafters going across a purlin mid span you would be willing to share do you?

When a rafter goes over a purlin the most logical joint would be a what is called a crows foot. Some people mistakenly call it a birds mouth. But that's a different joint.

This is an example of a birds mouth:



  

Here is an example of a crow foot:



 

In order to correctly layout a crows foot seat cut and plumb cut on a rafter you have to know where it is going to be.
You need accurate dimension and you have to lay it out from the top surface of the rafter, as this is the reference edge.
So when I do it, I draw out the little triangle to create the point where the level seat cut and the vertical plumb cut should meet.
Here in this example of a 12/12 rafter, we see that the dimensions for the vertical leg of the layout is 10 1/2" and when we travel down the rafter 7 7/16" and make a line 90° to the surface we get another point 7 7/16" in. This is where the seat corner should be.

You can't just draw and cut it based on the bottom surface of the rafter as the bottom surface is not a reference side, unless your timbers are planed square and true dimension.
With rough sawn lumber you have to layout from a constant surface and whatever size the seat cut and plumb cut come out to be is what it is.

The seat cut should be at least 2" by code, I think. Don't quote me on that I haven't looked it up lately and I am just going by memory.

There are other variations of seats for rafters going over purlins.
You could download the free pdf files from the guild site which shows these.
If you need a link, let me know. And I'll post one tomorrow.

Jim Rogers

[rmawhinney]

Thank you Jim again that is just what I was looking for. And thank you for those tips! I will head to the guild and try to find those pdfs right now. At the crows foot would you use a timberlock screw or something different to fasten there at that joint?

[rmawhinney]

I am posting my plans with joints and some modifications in the plan depository under 32x40 in maine

[Jim_Rogers]

At the crows foot would you use a timberlock screw or something different to fasten there at that joint?

Yes, with at least 2" of threads into the purlin plate.

Jim Rogers

[rmawhinney]

Perfect that is simple enough!

Thanks Jim!