I was in the April 2008 class. I was wondering, since it was not discussed in class, if there is a way to use logs as rafters? I understand that they would require some preparation beside just debarking them. Could they be flattened on the one side with a draw knife so that the car decking would have a flat surface to nail to or would that even be necessary? I remember that Ellsworth recommended purchasing beams but I have noticed a lot of the homes I have seen have used whole logs in the ceiling and I like the look, plus I have more logs than money. I am planning my practice shed so I would like some input before I go ahead. Thanks
Sharon McClure
They were spoken about not using them in my class = difficult. Ellsworth said that they all need to be the same size. I like them also so asked well how about milled logs for rafters--he said sure. I am not sure as to all the other construction process needed so cannot answer. Rod plans on using the log rafters maybe he will say something.
You need to carefully catalog them, it is OK if they are not all exactly the same size, as long as you use the larger ones near the front of the building and then use the rest in a sequential descending order. You also need to roll these logs and "CROWN" them that is if there is a slight bow in the log you want it UP. the caveat is that it will want to roll if it is very exaggerated. As a wise log builder once said " them logs that resemble the bottom of a birdcage, I puts dem in da BACK" .
I like to half-lap the intersection of the rafters at the peak, http://woodworking.about.com/od/joinery/p/halfLapJoints.htm this creates a continuous line of rafter from side to side of the building. As the area being half-lapped only involves a span of where the log touches the apex of the ridge pole to the peak (usually about a foot) I have trouble imagining any significant loss of structural integrity.
You can do log rafters with a lot less effort if you lay it all out on the ground first! That way you can (again) adjust the crown of the log up and easily switch rafter logs that are not working in the particular spot you have them BEFORE flying them into place.
If you have a crane with a spreader bar, you can even bolt the rafters together on the ground and fly the whole set into place at once, I did that at priest lake. It takes some patience and trial and error to get the pick points perfect but it sure saved a ton of time, since the rafters are already bolted they just hang on the ridge and can be easily adjusted for position.
What you will look out for is the variations in the plane of the T&G (tongue and groove) that rests on the rafters.
Sometimes if there is a slight dip in the rafter you can shim under the T&G and nail thru the shim, if there is a knot you can plane it off. ALSO remember you can shim and trim where the rafter logs rest on the ridge and the cap. Lay them all out first before doing so.
Mikey helpful hint : when installing t&G remember the first course has to be absolutely straight, this will help subsequent courses, if you get a board that is warped you can screw a cleat onto the rafter cut a wood wedge out of T&G so the groove fits over the tongue and tap it bringing the board in line.
Mikey helpful hint : stop every so often and measure to the peak at different points --- lets say you have 8 courses left and your east side is 1" low, you can fudge it up 1/8th of an inch over the next 8 courses and it will not be noticeable.
Mikey helpful hint : I always MARK the ridge pole and cap logs with 4 foot (or whatever spacing) marks before flying them into place, I cannot say what a pain-in-the-ass it is to be 30 feet up with a rag tape trying to measure and space rafters , even if your spaces end up being a bit off once the logs are flown into place you can offset a lot easier than you can measure the whole thing at altitude.
So suppose you have a 10 inch diameter rafter and your next log is 11 inches, you can certainly adjust a bit to compensate, preferably by raising the 10 inch log a bit with a shim and not cutting into it. I have made slight slight cuts into the cap log to adjust the height of rafters, never into the ridge pole or rafters themselves. You just do not want to pair a 16 inch log next to a 9 inch log.
MIKEY'S HELPFUL HINT TO SAVE YOU DAYS OF LABOR!!! LISTEN UP ! Put the bird blocks in AS YOU GO that way you can slide one of the rafters a bit to more easily get the bird block ends ( which will be concave) to match up and to fit into the space between the two round logs, otherwise the time factor at least triples if not quadruples.
MIKEY"S other helpful hint, STRINGLINE the top of the birdblock line before installing them, how many times have I seen birdblocks wacko out of line, way too many, it looks horrible.
ALWAYS stand back and look at this phase or any phase of the project as it progresses. What happens is people forget to do that and get tunnel vision.
Slight variations in the plane of the roof are pretty much immaterial, before anyone gets up in arms, I said slight.
What you are doing is trading time for money. I agree with Ellsworth and everyone who said it is easier with timbers. I also feel that the time and effort in doing it the old fashioned way is not a bad thing. Money is tight for almost everyone right now. Just take your time and just start in on it. you will do fine.
Now I know that this is not taught in class as pictured above. Is this strong? No bolts to secure it up/ just on foundation and ridge pole? I was just wondering because I have some ideas on using this, but to me it just don't seem strong enough. My ideas are not log home related just another type structure.
(edit) is that a log coming from wall toeing into support log? looks like it is just above the window--hmm
The compression strength of wood is enormous, that is columnar ( vertical) logs of the same density and specie are much stronger than horizontal span logs.
In this particular case IF: the rafters are decked to prevent racking, there is a bolted RPSL at the opposite end and the exterior RPSL has a drift pin at the bottom and is spiked at the top it should be fine. Of course the bottom of the exterior RPSL is not visible so I cannot make a call, the building looks really great though !
The specific geographical location will determine whether or not you ought have logs and columns subject to weather.
In the pacific NW I would NEVER leave a log protruding beyond dripline. In the Atacama desert I probably would not care a bit,,,,,
I have been called to sites many times to offer up remedies for dry rot and such, same with the bottom of columns subject to rain via wind.If the dryrot is left too long, it travels the grain of the log and you REALLY have problems.
The alternatives are : moving the support back a bit, using a 45 degree knee brace off the top log of the gable, or having a larger diameter ridge pole.
For column bottom-rot remedy I usually advocate using sonotube to raise the bottom of the log to whatever height it takes to get it out of the rain.
Comments
using log rafters
I was in the April 2008 class. I was wondering, since it was not discussed in class, if there is a way to use logs as rafters? I understand that they would require some preparation beside just debarking them. Could they be flattened on the one side with a draw knife so that the car decking would have a flat surface to nail to or would that even be necessary? I remember that Ellsworth recommended purchasing beams but I have noticed a lot of the homes I have seen have used whole logs in the ceiling and I like the look, plus I have more logs than money. I am planning my practice shed so I would like some input before I go ahead. Thanks
Sharon McClure
Log for Rafters
They were spoken about not using them in my class = difficult. Ellsworth said that they all need to be the same size. I like them also so asked well how about milled logs for rafters--he said sure. I am not sure as to all the other construction process needed so cannot answer. Rod plans on using the log rafters maybe he will say something.
log rafters
You need to carefully catalog them, it is OK if they are not all exactly the same size, as long as you use the larger ones near the front of the building and then use the rest in a sequential descending order. You also need to roll these logs and "CROWN" them that is if there is a slight bow in the log you want it UP. the caveat is that it will want to roll if it is very exaggerated. As a wise log builder once said " them logs that resemble the bottom of a birdcage, I puts dem in da BACK" .
I like to half-lap the intersection of the rafters at the peak, http://woodworking.about.com/od/joinery/p/halfLapJoints.htm this creates a continuous line of rafter from side to side of the building. As the area being half-lapped only involves a span of where the log touches the apex of the ridge pole to the peak (usually about a foot) I have trouble imagining any significant loss of structural integrity.
You can do log rafters with a lot less effort if you lay it all out on the ground first! That way you can (again) adjust the crown of the log up and easily switch rafter logs that are not working in the particular spot you have them BEFORE flying them into place.
If you have a crane with a spreader bar, you can even bolt the rafters together on the ground and fly the whole set into place at once, I did that at priest lake. It takes some patience and trial and error to get the pick points perfect but it sure saved a ton of time, since the rafters are already bolted they just hang on the ridge and can be easily adjusted for position.
What you will look out for is the variations in the plane of the T&G (tongue and groove) that rests on the rafters.
Sometimes if there is a slight dip in the rafter you can shim under the T&G and nail thru the shim, if there is a knot you can plane it off. ALSO remember you can shim and trim where the rafter logs rest on the ridge and the cap. Lay them all out first before doing so.
Mikey helpful hint : when installing t&G remember the first course has to be absolutely straight, this will help subsequent courses, if you get a board that is warped you can screw a cleat onto the rafter cut a wood wedge out of T&G so the groove fits over the tongue and tap it bringing the board in line.
Mikey helpful hint : stop every so often and measure to the peak at different points --- lets say you have 8 courses left and your east side is 1" low, you can fudge it up 1/8th of an inch over the next 8 courses and it will not be noticeable.
Mikey helpful hint : I always MARK the ridge pole and cap logs with 4 foot (or whatever spacing) marks before flying them into place, I cannot say what a pain-in-the-ass it is to be 30 feet up with a rag tape trying to measure and space rafters , even if your spaces end up being a bit off once the logs are flown into place you can offset a lot easier than you can measure the whole thing at altitude.
So suppose you have a 10 inch diameter rafter and your next log is 11 inches, you can certainly adjust a bit to compensate, preferably by raising the 10 inch log a bit with a shim and not cutting into it. I have made slight slight cuts into the cap log to adjust the height of rafters, never into the ridge pole or rafters themselves. You just do not want to pair a 16 inch log next to a 9 inch log.
MIKEY'S HELPFUL HINT TO SAVE YOU DAYS OF LABOR!!! LISTEN UP ! Put the bird blocks in AS YOU GO that way you can slide one of the rafters a bit to more easily get the bird block ends ( which will be concave) to match up and to fit into the space between the two round logs, otherwise the time factor at least triples if not quadruples.
MIKEY"S other helpful hint, STRINGLINE the top of the birdblock line before installing them, how many times have I seen birdblocks wacko out of line, way too many, it looks horrible.
ALWAYS stand back and look at this phase or any phase of the project as it progresses. What happens is people forget to do that and get tunnel vision.
Slight variations in the plane of the roof are pretty much immaterial, before anyone gets up in arms, I said slight.
What you are doing is trading time for money. I agree with Ellsworth and everyone who said it is easier with timbers. I also feel that the time and effort in doing it the old fashioned way is not a bad thing. Money is tight for almost everyone right now. Just take your time and just start in on it. you will do fine.
I hope this helped.
Mikey, journeyman class 1987
loghomeguy@msn.com
Cle elum Log Home size
This log home looks fantastic. Any chance of getting the room sizes and layout?
David
ridge pole support log?
Now I know that this is not taught in class as pictured above. Is this strong? No bolts to secure it up/ just on foundation and ridge pole? I was just wondering because I have some ideas on using this, but to me it just don't seem strong enough. My ideas are not log home related just another type structure.
(edit) is that a log coming from wall toeing into support log? looks like it is just above the window--hmm
In RE: RPSL? -timber
The compression strength of wood is enormous, that is columnar ( vertical) logs of the same density and specie are much stronger than horizontal span logs.
In this particular case IF: the rafters are decked to prevent racking, there is a bolted RPSL at the opposite end and the exterior RPSL has a drift pin at the bottom and is spiked at the top it should be fine. Of course the bottom of the exterior RPSL is not visible so I cannot make a call, the building looks really great though !
The specific geographical location will determine whether or not you ought have logs and columns subject to weather.
In the pacific NW I would NEVER leave a log protruding beyond dripline. In the Atacama desert I probably would not care a bit,,,,,
I have been called to sites many times to offer up remedies for dry rot and such, same with the bottom of columns subject to rain via wind.If the dryrot is left too long, it travels the grain of the log and you REALLY have problems.
The alternatives are : moving the support back a bit, using a 45 degree knee brace off the top log of the gable, or having a larger diameter ridge pole.
For column bottom-rot remedy I usually advocate using sonotube to raise the bottom of the log to whatever height it takes to get it out of the rain.