25' beams

[sachsmo]

Uhhh,

Lumbermen sell Lumber do they not?

Wonder how some of the huge barns were built back in the day without engineered lumber?

 

[les-or-more]

Uhhh,

Lumbermen sell Lumber do they not?

Wonder how some of the huge barns were built back in the day without engineered lumber?

The Amish are still building them today.

 

[sachsmo]

Deflection, Bah,

Used to work at a pre-stressed concrete plant.

We made 100'+ bridge beams I could stand in the middle of them and jump, that beam would quiver like jello.

Yup them things could span a good bit!

 

[Beefie]

Thanks guys for your feed back. I was at my neighbors over hunting season. He has his house at the widest 30' and he has 2 pine logs spaced at 10' apart that go the hole 30' length. No deflecton noted and it has been built for 8 years and heated with wood the whole time. I am trying to find a program for google sketchup. Like google for dummies. I can rough draw everything but can't figure out the sketch up program.

beefie

 

[Beefie]

For you guys that have milled long stuff using a ladder or a plank. How do you get the supports set for your moves? I thought there had been some pictures but I think they are gone after the linkbucks debaclke. Reading on strings or something. Anybody have pictures or a video.

New 36" Alaskan and mini mill has been ordered and should get in 7-15 days, cant wait !!!!!!!!!

Beefie

 

[psgflier]

I made an aluminum frame - two pieces of 1 1/2 angle with 2" flat stock welded 2' apart separating the angles about 10". I screwed a 1x10 to the frame, and melted wax into the wood to protect from water and make the board slippery. I made my guide 10' long, but 6 or 8 would be fine.
I put 3/8' lag bolts into the log paired every 2', The angles on the guide ride on the heads of the lags. I put a board on each end of the log and ran two string lines 9" apart from one end of the log to the other, and set the heads of the lags to just touch the string. After removing the end templates, the guide board slides on the lags, and the mill slides on the board.
It takes a little time to set this up, but after the first two cuts goes pretty good.
I've cut timbers up to 45' long with no more than 1/8 variance in dimension in the timber.

 

[Beefie]

Melted wax, that is a new one for me. What type of wax are you using? Would boiled lindseed oil work as well?

Beefie

 

[psgflier]

I suppose it would work fine. The main purpose is to protect the wood from the weather. We get up to 200" of rain a year, and when the humidity gets down to 60% we think it's dry.
I have had some trouble with dimensional stability on some wooden guides due to moisture changes in the wood.
I use a propane torch to heat the plank and melt paraffin into the wood. Heating the wood opens the pores and gives good penetration. Much like waxing a ski.


Re guarding your cabin; I don't know if you need a building permit, but the building inspector would be a good place to get the requirements for your design.
I'm pretty sure a 4x12 would be sufficient, but you could always go deeper with a 4x14. Laminated beams are stronger because of alternating the grain between pieces, but is limited by the fasteners.
Steel increases practical strength, but, ask your fire chief, is frowned on in practice because of its failure in a fire.
Only the beam supporting the loft needs to support more than its weight, and weight supported by the beam under the loft is the weight of the beam, 1/2 the weight of the floor, and 1/2 the live load on the loft(beds, people, etc.)
If your building a building with equal wall heights on all four walls, a double pitch roof with rafters meeting at a ridge pole, you need at least the two beams you're talking about to act as collar ties; to keep the walls from spreading under the load of the roof.

Carl

 

[Beefie]

I suppose it would work fine. The main purpose is to protect the wood from the weather. We get up to 200" of rain a year, and when the humidity gets down to 60% we think it's dry.
I have had some trouble with dimensional stability on some wooden guides due to moisture changes in the wood.
I use a propane torch to heat the plank and melt paraffin into the wood. Heating the wood opens the pores and gives good penetration. Much like waxing a ski.


Re guarding your cabin; I don't know if you need a building permit, but the building inspector would be a good place to get the requirements for your design.
I'm pretty sure a 4x12 would be sufficient, but you could always go deeper with a 4x14. Laminated beams are stronger because of alternating the grain between pieces, but is limited by the fasteners.
Steel increases practical strength, but, ask your fire chief, is frowned on in practice because of its failure in a fire.
Only the beam supporting the loft needs to support more than its weight, and weight supported by the beam under the loft is the weight of the beam, 1/2 the weight of the floor, and 1/2 the live load on the loft(beds, people, etc.)
If your building a building with equal wall heights on all four walls, a double pitch roof with rafters meeting at a ridge pole, you need at least the two beams you're talking about to act as collar ties; to keep the walls from spreading under the load of the roof.

Carl

My thought was to have 5 beams spaced at 2' apart to support the loft floor and 2 beams at 5' apart to tye the walls. One log will go at the edge of the loft and help support the end loft beam and support the ridge beam. proablly not needed but what the heck.

The only thing Im wondering about is the span on the 25' beams for the loft. I might have to put in a wall hafe way underneath and have 2 12' rooms instead of one big room. If I did that I could do 12' loft joists instead.

Not sure yet, I am having one of the town board members e-mail me the building inspectors info to see what he wants.

Beefie

 

[Winn R]

Although milling logs fall into that area of I hope I do this someday, I know something of engineering.

If the long span logs, the loft floor joists, can be made a bit longer so that the ends cantilever out beyond the support walls; it will reduce deflection. The loft floor can be utilized as well, if you're considering a tongue and groove, by dispersing the forces over a larger area. The vertical member extending from the loft edge to the ridge pole could have the opposite function, supporting the long span floor structure.

Good luck with your project!

 

[Beefie]

Cantilever is not a option. Worst case I will just put in a support wall at 12' . Is there a program or calculator that gives load ratings for 2x12-3x12 etc?

Beefie

 

[Winn R]

http://www.awc.org/pdf/WSDD/TOC.pdf

This is the bible for wood structures although I'm not sure you can access it all on line. You'll have lots of fun studying over it!

 

[Beefie]

http://www.awc.org/pdf/WSDD/TOC.pdf

This is the bible for wood structures although I'm not sure you can access it all on line. You'll have lots of fun studying over it!

Thanks Winn R that's what I was looking for.

Beefie

 

[sachsmo]

Here's a link where you can read to your hearts content, or buy a PDF or hardcopy.

http://www.awc.org/standards/wsdd.php