A shop question...

xalky said:
Are you planning on using the upper part for storage? If so, you'll want to build it as a floor. If not, you can go much lighter on the framing materials if its basically gonna be just to hold in the heat. It'll probably be cheapest to put one large carrying beam down the center and smaller joists for the half span. A nice steel beam spanned across the 21 ft would be the way I'd do it.

In case your wondering, I'm a builder, I've done hundreds of them. ;)
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Thank you! Yes I am planning on using the upper part as storage. So if I can ask, you would put a metal I beam across the 21' part....what size? Also what size joists would you run to it? And I'm guessing to use a post to support it in the center? Sorry for all the questions, just trying to figure out how to do this. I don't want the ceiling to fall down on me lol.

Thanks,
Chris
 
>>>>>Where does the strength come from?

Sorry, I did not mean to imply that there was no need for depth to get strength. What I was really trying to say was if you wander around in most new houses you will see massive joists that are much larger than required for the weight they carry but are needed if you want a nice stiff floor that doesn't bounce when you walk across it. My house was built in 1917 and they used 2x6 joists on 16" centers with a 14 foot span. It has been here nearly 100 years and nothing has fallen through the floor (including the piano) but it is quite bouncy. Where we had trouble with things rattling I put in 5" steel I beam which feels like walking on rock. I am sure there are span tables that can tell you what size I beam you need for a given load but I don't have them here. Perhaps Google?

Brian
 
Aaaahhh gotcha. Sorry to ask the dumb questions. I don't care if it bounces..I just don't want it fall in on me lol.

Thanks
Chris
 
Tamper84 said:
Thank you! Yes I am planning on using the upper part as storage. So if I can ask, you would put a metal I beam across the 21' part....what size? Also what size joists would you run to it? And I'm guessing to use a post to support it in the center? Sorry for all the questions, just trying to figure out how to do this. I don't want the ceiling to fall down on me lol.

Thanks,
Chris
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I thought that you wanted no columns at all.
If you wanted to put a post in the center at let's say 10'6", a wood beam would be a cheaper option . 3 2x10s nailed together would be ample for the carrying beam. 2x8s @ 16" on center would be plenty for the floor for a 13ft span.

The other option is to run the wood beam in the other direction, across the 26ft span, with a column at 13ft, use 3 2x12s nailed together for the beam. So now your joists would only span 10'6". Then you could use 2x6 joists@ 16" on center. This would probably be your cheapest option. If it'll only be used for storage you could get away with 1/2" cdx for the floor.

Using a column in the middle makes a lot of sense for cost reasons. But you will have a column. For no column, a minimum of a 12" deep steel beam would be my recommendation across the 21' -span, with 13 ft 2x8s for joists. You could also do that span with some lvl beams aka; microlams. But I'm thinking you would need a minimum of 3 16" deep lvls to do the job across the 21 ft span.

The longer you span, the deeper the lumber has to be to remove the springing. A column all but eliminates that issue.

The above recommendations are the minimums for a floor. You could probably go a little less but you might regret it in the future. An extra $500 now might save you some self imposed a$$ kicking down the road.;)
 
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You can find an example of the kind of span table you need at:
http://www.toolbase.org/PDF/DesignGuides/ResidentialSteelLoad_SpanTables.pdf

The tributary distance is 1/2 the joists being supported by the beam so in your case, 1/2 of 13 + 1/2 of 13 or in other words, 13'. Since you will not be walking around on it you have a dead load. You need to check this but from memory, I think they normally figure 40 lb per square foot for live loads and I think dead load is 1/4 of a live load. Unless you can find a used beam, it is probably a moot point as the cost can go up pretty quickly with a larger beam.

xalky clearly has more real world experience than I do so I would be inclined to listen to him for a pretty good starting point.

Brian
 
Thank you all for your help!!! Im liking this place more and more!!! I really do appreciate it! I hope I can repay all of this advice!!

Thanks,
Chris
 
By the time you screw around with some kind of center beam, posts for it, and footers for the posts you might as well go with the engineered floor joists. Tell the lumber yard your clear span/ length criteria and floor loading requirements and they will size them for you. If you are going to drywall the under side be sure to tell them that too.

With that span you probably want to put in two sets of blocking so the joists (whatever they are) dont have a tendency to rotate on you.

Im with the others on the 10' ceiling too.
 
Hawkeye said:
On the topic of lighting, has anyone used the newer T5 fluorescent lights? They cost more, but they do an amazing job. They do work better, however, with a higher ceiling. With any type of fluorescent, I always recommend at least a 4100K colour temperature, preferably 5000K. (I have some 6500K tubes) These are closer to sunlight, which is what your eyes were made to use. The old Warm White tubes are 2700K.
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Yes! Just built a shop and went with the T5s instead of Highbays in the tall section of the shop. My machine shop section only has 8' ceilings, so I used t8s there. The T5s make the t8s look like 1930's incandecents. They work really well, but as you say, you need the height for them to work well. It would be a little harsh with them right above your head in a <12' ceiling shop. In BC there's some attractive retrofit rebates available, but unfortunately for me, nothing for new construction.

-kelly
 
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