Replies

1. 
   Fred_Matthews | Jan 12, 1999 09:04am | #1

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   There is no reason you can't mix wood and metal-in fact, if long, clear spans are what you want, it's the only way to go. You might consider a Butler type building. These are pre-engineered steel buildings, normally w sheet metal skins. But you should talk to them, they certainly could engineer the framing which basically consists of rigid steel bents connected w purlins and laterally braced w wire rope and turnbuckles. You then supply the outer skin which can be screwed to the frame. I would consider some type of felt to isolate the wood from metal and prevent any condensation related problems.

2. 
   Guest_ | Jan 12, 1999 08:26pm | #2

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   Have you talked to a wood frame fabricator? There was an article in Rural Builder about an industrial building with 90' clear spans with all wood posts and wood trusses. Just how big of boat are you building?

1. 
   Guest_ | Jan 13, 1999 01:43am | #3

   *In my house project I have been mixing some steel with wood. I can see why wood framers don't like to use steel and visa versa. The interface between the two tends to be a problem and you need a different set of tools to handle steel. As a tool junkie, I have enough stuff to be able to work with both of them. I have found steel to be significantly less expensive then the equivalent in wood. A 10 inch light-weight beam cost me $2.70 per foot. The ll 7/8 inch TJ Pros were a $1.32 per foot and I would have needed 3 in parallel to carry the load. The 10 inch beam was far stronger than even 3 of the TJs. To match the height of the 11 7/8 TJs, I used self tapping screws to attach a 2x4 on top as a nailer for the decking, though I still have an 1/8 inch to make up for. The interface between the two materials is the reason you tend to see one or the other. If you plan for these connection points you can minimize the adverse effects where wood and steel meet.

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   Guest_ | Jan 13, 1999 08:19am | #4

   *I see two options. First, a steel frame with wood purlins and roof decking and horizontal wood strapping with board and batten or T1-11 type siding. At one time Miracle Truss used this kind of system. Second, a conventional wood structure built around a system of vertical metal posts and overhead tracks for your chain or cable hoists.May be hard to find off-the-shelf steel trusses that will carry any additional weight beyond the roof and snow load. Think the purpopse built lifting system in a wooden building will work the best. A simple post and span I-beam with a chain or cable hoist carrage should be rather straight forward. Vertical lift and side-to-side. Adding overhead movement in a third plane, i.e., up-down, left-right, and forward-back requires a rather complex system of tracks and carrages and may be overkill for a small boat shop. Alternatively, you could construct something like a "swing set" on casters. Common in automotive shops to lift and move engines. Take up a lot of space and require clear floors which may be hard to find in a boat shop. Companies like Northern Hydraulics stock chain hoist carrages that ride on I-bars and the hoists. Don't know what kind of weight you are talking about but if it is significant you may want to run your design by a professional engineer. Good luck!

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   Guest_ | Jan 15, 1999 01:09am | #5

   *Try http://www.mindspring.com/~morgans/polebarn.htm for a look at the kind of project you are considering. The Morgans used rafters supported at the mid point by interior posts and girts. If you frame in wood trusses will be the easiest way to get a clear span. If you elect a metal frame talk with your vendor about overhead hoists. they can size according to your needs.

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   Guest_ | Jan 15, 1999 01:37am | #6

   *DaveI would suggest the way shipyards and large factories are built. They essentially start with a bridge crane, weld on some clips, and attach curtain walls and roof rafters. I would guess that you would have an underrunning bridge (trolleys hang under the I-beam) this gives you plenty of steel on top to weld clips and attach roof joists. You see the structure of larger cranes has to take side loads that are 125% of hook rating. In addition the framework is usually designed with incredible safety factors such that roof and snow loads are minimal. Weight of wall panels is transferred to the foundation. It is possible to detail this in such a way that you could get a second floor. Call some used equipment dealers - you may be surprised how cheaply you can get a free standing bridge. I was considering incorporating industrial pallet racking to support one rail for my barn. This would provide plenty of vertical and lateral support, as well as give you tons of storage. (not a bad pun) This stuff used is quite cheap - we sell it for scrap at work.-Rob

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   Guest_ | Jan 19, 1999 06:29am | #8

   *Thanks everyone for the info. Getting further down the road in planning this project,these ideas have spawned a few more.

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   Guest_ | Jan 19, 1999 06:29am | #7

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   Just in the thinking stages of building a barn structure primarily for working on boats during the winter.
   Want a design with the strength and clear span of a steel frame and the aesthetics of wood outside. Would like to use the steel ceiling joists to support and move various parts around.
   Has anyone seen any publications or info on mixing the materials or is there some good reason why there only seem to be
   steel buildings(ugly) and wood buildings.
   It seems to me that a steel post and beam structure would be perfect?