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Old 02-15-2012, 09:45 PM   #1
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Roof framing


I have a studio that I am remodeling the main room is 10'x18'. It was built in the 50's all 2x4 construction everything is 24" oc. The original low ceiling was drywall. I want to remove the 4 2x4's that run the length of the ceiling 18ft, so I can have an open cathedral ceiling. Are these 2x4's serving any purpose? Would it be safe to remove them?
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Old 02-15-2012, 10:09 PM   #2
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I have a studio that I am remodeling the main room is 10'x18'. It was built in the 50's all 2x4 construction everything is 24" oc. The original low ceiling was drywall. I want to remove the 4 2x4's that run the length of the ceiling 18ft, so I can have an open cathedral ceiling. Are these 2x4's serving any purpose? Would it be safe to remove them?
Well that depends on if you want your roof to come crashing down on you? those are key parts to your truss system that is the bottom cord. Don't remove them! one thing you need to do is if you want a cathedral ceiling is replace the roof with scissor jack trusses. what you want to do is not a DIY project.

Also remove the insulation and drop it in to the bottom cord of the truss.

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Old 02-15-2012, 11:22 PM   #3
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Roof framing


In other words, those 2x4's are keeping your walls from pushing out.

The only way you could safely remove them would be to have a ridge beam that could support the full weight of the roof.

I'm in the middle of a 2-story addition right now...the upstairs is going to be vaulted ceilings....I have a ridge beam running down the center that is a PSL beam 5.25x11.25....total length is about 32' with a support in the middle.
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Old 02-15-2012, 11:33 PM   #4
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Roof framing


a roofer installs roofing material like shingles and metal what you need is an engineer what you have are rafters not trusses and a ridge beam is not all you would need and the person who stated if you would remove the bottom board and the walls would fall is probably correct depend on a few factors that an engineer could explain to you the best solution would be to take the suggestion about getting new trusses
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Old 02-16-2012, 12:21 AM   #5
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Thanks. I think I'll leave it as it is.
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Old 02-16-2012, 09:47 AM   #6
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Thanks. I think I'll leave it as it is.

Good idea.

Question, did you notice any sag in the ceiling at all when the drywall was on there?
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Old 02-16-2012, 10:11 AM   #7
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For future reference, the 2x4 floor joists are sometimes called rafter ties, although a better name might be wall ties. They do in fact structurally provide the lateral resistance that keeps your walls from spreading outward. I notice you have a relatively short horizontal board up near the top of the rafter. These are called collar ties. They are probably the most misunderstood structural element in your roof.

A lot of people think they act to keep the ridge from sagging, but they don't. Some people think they keep the walls from spreading, but they don't. All they do is equalize uplift forces on the roof in the event of a severe wind storm. They are important, but not crucial. The rafter ties (your ceiling joists) are crucial.

And as another point of reference, the roof system you have is typically referred to as a rafter system. Although it is technically a truss system, since the definition of a truss is a structural framework based on the rigidity of the triangle, it is not often thought of as a truss because there is exactly one triangle (formed by two rafters and the floor joist). Any roof truss system you order is going to have multiple pieces of lumber arranged in triangles, typically held together with special splice plates.
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Old 02-16-2012, 10:17 AM   #8
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If that insulation is installed tight up to the sheathing without foam baffles and no ridge vent the shingles will be super heated and shorten there life drasticly.
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Old 02-16-2012, 06:50 PM   #9
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Originally Posted by Daniel Holzman
And as another point of reference, the roof system you have is typically referred to as a rafter system. Although it is technically a truss system, since the definition of a truss is a structural framework based on the rigidity of the triangle, it is not often thought of as a truss because there is exactly one triangle (formed by two rafters and the floor joist).
Do rafters and joists form a true definitive triangle, given that the rafters are not in the same plane as the joists? I always thought this was the key difference between the two configurations (truss vs. rafter/joists)
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Old 02-16-2012, 07:08 PM   #10
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Even though the rafters are slightly offset from the joists, they still form a triangle for structural analysis purposes, so technically they form a one triangle truss.
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Old 02-16-2012, 07:21 PM   #11
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What about gambrel roofs which have no triangles? Are those simply rafters with joists?
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Old 02-16-2012, 08:00 PM   #12
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Quote:
Originally Posted by Daniel Holzman View Post
For future reference, the 2x4 floor joists are sometimes called rafter ties, although a better name might be wall ties. They do in fact structurally provide the lateral resistance that keeps your walls from spreading outward. I notice you have a relatively short horizontal board up near the top of the rafter. These are called collar ties. They are probably the most misunderstood structural element in your roof.

A lot of people think they act to keep the ridge from sagging, but they don't. Some people think they keep the walls from spreading, but they don't. All they do is equalize uplift forces on the roof in the event of a severe wind storm. They are important, but not crucial. The rafter ties (your ceiling joists) are crucial.

And as another point of reference, the roof system you have is typically referred to as a rafter system. Although it is technically a truss system, since the definition of a truss is a structural framework based on the rigidity of the triangle, it is not often thought of as a truss because there is exactly one triangle (formed by two rafters and the floor joist). Any roof truss system you order is going to have multiple pieces of lumber arranged in triangles, typically held together with special splice plates.

that sounds a little odd from what ive been taught as a licensed carpenter specializing in home construction.. ceiling joists tie the two opposite walls together which keeps them from spreadig.. by keepig them from spreading the ridge will not drop. ceiling joists are at the height of the double top plate. collar ties are in the top 1/3 of the total rise of the roof system
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Old 02-17-2012, 08:01 AM   #13
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I was talking about the collar ties not providing the lateral resistance. You are correct, the floor joists (floor from the perspective of the attic, ceiling from the perspective of the floor below) provide the lateral resistance to spreading.

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