Shed framing - is this safe?


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Old 03-25-15, 02:05 AM
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Shed framing - is this safe?

Hi all, I'm new here and I have a question about cutting a beam out of the support structure in the roof of my shed. My question is, is this safe and will the roof be structurally sound if I cut a section of this beam out? is there a way I can strengthen the beam if it is cut? I've attached a picture, the middle beam (or 2nd one down) is the one I'm referring to, thank you.

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Old 03-25-15, 02:47 AM
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Welcome to the forums! Why do you see the need to cut the collar tie? It is there to keep the walls from splaying outwardly. While cutting it may not cause the shed to fall down, it is part of the integrity of the whole building.
 
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Old 03-25-15, 06:22 AM
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That looks like a gambrel roof, thus there is no top plate on each end of the collar tie and thus nothing to add resistance to the roof sagging down while the old ends move apart. Guessing, but they also look to be spaced 24" on center, which would leave a 4' gap if one were removed.

Are you thinking about removing an entire beam or just a few feet in the middle?

Bud
 
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Old 03-25-15, 08:55 AM
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Are you in snow country? If so, NO!. If you live in a place that gets only light to no snow, there is a way to do it. The purpose of the collar beam is to stop the walls from spreading outward due to roof load. Every roof is designed to withsand a maximum load meaured in pounds per square foot. A shed roof like this one would be rated very light roof load. The "Truss structure" is put together properly with what appear to be good gussets and not just nailed together. So, I do not see any real issues other than making sure you do the modification proeperly.

Here is how to do it IF YOU ARE NOT IN SNOW COUNTRY!! You run a 2x6 from the rafter in the back rafter to the one just past the collar tie you are removing. There will be two of them, on each side of the shed. The 2x6's are running parallel to the peak, about a foot from the top plate (walls). Screw two 2.5" screws through the 2x6 into the rafters. Alternatively, you could run the 2x6 stringers from under the three collar ties and simply remove the center collar tie at the inside edges of the stringers if you are okay with removing only the inner 2/3s of the collar tie. What you are doing is transferring the "spread" or lateral load to the other two collar ties via the rafters. When you consider all the load spreading material, from the rafters to the collar ties to the sheathings and decking, this little load transfer trick will not harm the shed. Yes, it will weaken it slightly. It's never a good idea to cut a main structural member in any structure. But, you can do it safely when you consider all the factors.

Since this is a shed and not a dwelling or occupancy, I don't see any permitting problems.
 
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Old 03-25-15, 05:03 PM
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Thank you all for the replies. My intention was to build a faraday cage to put some old electronics/cds/dvds (yes cue the tinhats). I don't want to cut the entire collar tie, maybe just 4 ft or so. What if i built the box so that it fit right in the space where the collar tie is cut? would that compensate for the loss of integrity from cutting it? We do get a bit of snow up here, maybe ~ 2ft a year but no more than 1ft at a time, I'm sure that's still a lot of weight.
 
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Old 03-25-15, 06:29 PM
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I am curious why you want a Faraday cage for CDs and DVD's. They are not emissive or particularly receptive so I'm wondering what you're shielding them from?

If you are building a Faraday cage why do you need to cut the collar tie? A Faraday cage can be sized and shaped as needed. If you need more room incorporate the cage around the structure or just turn the entire shed into a big one.
 
 

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