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Truss uplift

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inspectorD

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Ok, another question.
Where is the main carry beam in the basement, and what is it made of. Dimensional lumber or LVL.
Pier under the opening may have sank.

Another is, I wonder if you have any blocking to the lower truss cord where the opening is. You can also get lateral movement at the top of the opening, which is the bottom of the truss cord.

Wind plays a part also on trusses, not just heat.
 

arnoldat30

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Two beams in the basement. One on each side of the opening, or so. No evidence of anything sinking. Sinking is the first thing I checked for. The crack closes back up in the summer. There is no lateral movement, or at least not that I can see.
 

inspectorD

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Two beams in the basement. One on each side of the opening, or so. No evidence of anything sinking. Sinking is the first thing I checked for. The crack closes back up in the summer. There is no lateral movement, or at least not that I can see.
If its dimensional lumber ..measure it.. I have had homes that the baseboard on the 3rd floor had a gap or 3/4 at the floor. All from the joists each shrinking half an inch during the winter months. Its amazing how much some homes move, and others do not. Depends on climate and conditions.
I think it could be a couple things at the same time in my opinion.

But one of those 3 things are causing that crack.
 

nealtw

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If its dimensional lumber ..measure it.. I have had homes that the baseboard on the 3rd floor had a gap or 3/4 at the floor. All from the joists each shrinking half an inch during the winter months. Its amazing how much some homes move, and others do not. Depends on climate and conditions.
I think it could be a couple things at the same time in my opinion.

But one of those 3 things are causing that crack.
If all the walls have the same number of plates, it would take extreme condition for the outside wall plates to expand that much and the gap would continue to the outside wall.??
 

nealtw

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Simpson has a continues rod system that would bolt the truss thru one of those walls to the beam below if not the floor, they have a ratcheting nut so as the shrinkage occurs the nut tightens and holds it in place.


The RTUD ratcheting take-up device is a cost-effective shrinkage compensation solution for continuous rod systems. The RTUD is now code-listed for use with rod systems to ensure highly reliable performance in a device that allows for unlimited shrinkage. Once the RTUD is installed, a series of internal threaded wedges enable the device to ratchet down the rod as the wood structure shrinks, but engage the rod in the reverse direction when under tensile loading. Continuous engagement is maintained on the rod at all times by the take-up device, enabling the rod system to perform as designed from the time of installation.

Key Features

Maintains rod-system tightness, allowing it to perform as designed
Pass-through design provides unlimited shrinkage compensation
Available for 1/2", 5/8" and 3/4" diameter threaded rod
Fastens easily to the wood plate with the BPRTUD bearing plate and (2) 8dx1 1/2" nails (minimum) or (2) #9x1 1/2" Strong-Drive® SD Connector screws (not included)
1.33-degree rod offset (1 3/4" max) allowed per floor
Very minimal force required to allow rod to pass through take-up device to mitigate rod buckling during wood shrinkage
Material


RTUD4_BPRTUD3-4_layer.jpeg

182d-2015.gif
 

inspectorD

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If all the walls have the same number of plates, it would take extreme condition for the outside wall plates to expand that much and the gap would continue to the outside wall.??
Its the interior of the building. The main beam shrinks but the concrete foundation walls stay put. The outside walls also have the stress skin of the plywood so not as much movement happens at the exterior. The interior walls fall inward so to speak.
Look at a fireplace exterior and look at the floor in front of it. The floor usually always slopes away from the hearth due to shrinkage.

The truss is the culprit at that seam... the solution is to find the movement.
To do that you need an engineer to see what can be modified at that connection for the truss.
 

bud16415

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That end truss wasn’t supposed to be a truss. You have the butterfly truss next to it to take the load. When he filled it in to have something to put the drywall on he made it into a truss with all the vertical studs attached top and bottom. Those studs are pulling up and forming the crack at the plate. I think I would block all the studs together on the back and then cut them free at the top. You will still get the movement at the top and a molding up there could cover it.

At least that’s what I see happening.
 

nealtw

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That end truss wasn’t supposed to be a truss. You have the butterfly truss next to it to take the load. When he filled it in to have something to put the drywall on he made it into a truss with all the vertical studs attached top and bottom. Those studs are pulling up and forming the crack at the plate. I think I would block all the studs together on the back and then cut them free at the top. You will still get the movement at the top and a molding up there could cover it.

At least that’s what I see happening.
I think you are looking at the wrong picture, his truss is flat bottom with fillers for drywall, I posted the other one showing a wall beside the scissor truss.
 

nealtw

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Its the interior of the building. The main beam shrinks but the concrete foundation walls stay put. The outside walls also have the stress skin of the plywood so not as much movement happens at the exterior. The interior walls fall inward so to speak.
Look at a fireplace exterior and look at the floor in front of it. The floor usually always slopes away from the hearth due to shrinkage.

The truss is the culprit at that seam... the solution is to find the movement.
To do that you need an engineer to see what can be modified at that connection for the truss.
The fireplace is an insert sitting on the floor so there will be nothing to see there. A string line strung across at the height of the outside walls will prove a sag in the floor or the uplift of the truss.
 

bud16415

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I think you are looking at the wrong picture, his truss is flat bottom with fillers for drywall, I posted the other one showing a wall beside the scissor truss.
Oh I see that now, his was a truss he just added a bunch of studs to it.

So he has no butterfly truss at the end?? What is his insulation stapled to?

A trim strip over the crack is looking better all the time.
 

nealtw

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Oh I see that now, his was a truss he just added a bunch of studs to it.

So he has no butterfly truss at the end?? What is his insulation stapled to?

A trim strip over the crack is looking better all the time.
They would have added a 2x4 to this side to match the scissor for the ceiling drywall and insulation.
 

inspectorD

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The fireplace is an insert sitting on the floor so there will be nothing to see there. A string line strung across at the height of the outside walls will prove a sag in the floor or the uplift of the truss.
Sorry Neal..I meant looking at a fireplace as an example of joists shrinking. Not this particular one.
 

nealtw

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Two beams in the basement. One on each side of the opening, or so. No evidence of anything sinking. Sinking is the first thing I checked for. The crack closes back up in the summer. There is no lateral movement, or at least not that I can see.
What did you build behind that truss for the insulation.
 

arnoldat30

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There is batting coming down about 16 inches from lower ceiling. Then 19 inches of blown in covering the remaining 16 inches and the other ceiling.
 

arnoldat30

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If I understand what you are asking, the batting is stapled on the 2x4s and I have some netting stuff on the back side holding it
 

nealtw

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If I understand what you are asking, the batting is stapled on the 2x4s and I have some netting stuff on the back side holding it
We would have built a wall behind that truss just for the insulation.
I have a fix but it won't be easy and you might be able to save the drywall.
I think it would be best when the gap has closed.
The trick will be to build a wall for the drywall and allow the truss to move.
I talked to a drywall hanger who has seen this before and they request the framing to be a 2x6 wall with the studs cut to go thru the truss with clearance for movement. Then they only screw the drywall to the studs and the would not screw the ceiling to the 2x4 that is on the face of the truss.

My next question was how do we do that now? And he had an answer.
So with a stud finder you can find the screws in the drywall and remove most of them.
From the attic side, remove the studs that were added to the truss.
2x4 bottom plate with a half in space between the truss and the plate.
2x6 studs with slightly over sized notches to clear the members of the truss
2x4 top plate, plumb the wall and brace it back to other trusses in the attic.
Re screw drywall to the new studs and remove the remaining screws that are into the truss.
He said if you have a sprayed ceiling and you don't want to remove screws into that 2x4 above you could pull the nails and let the 2x4 float too.

This doesn't sound like fun but the drywall would be one with the lower wall and the truss would be allowed to move up and down. for inspector, the walls could move up and down.

Thought?
 

inspectorD

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We would have built a wall behind that truss just for the insulation.
I have a fix but it won't be easy and you might be able to save the drywall.
I think it would be best when the gap has closed.
The trick will be to build a wall for the drywall and allow the truss to move.
I talked to a drywall hanger who has seen this before and they request the framing to be a 2x6 wall with the studs cut to go thru the truss with clearance for movement. Then they only screw the drywall to the studs and the would not screw the ceiling to the 2x4 that is on the face of the truss.

My next question was how do we do that now? And he had an answer.
So with a stud finder you can find the screws in the drywall and remove most of them.
From the attic side, remove the studs that were added to the truss.
2x4 bottom plate with a half in space between the truss and the plate.
2x6 studs with slightly over sized notches to clear the members of the truss
2x4 top plate, plumb the wall and brace it back to other trusses in the attic.
Re screw drywall to the new studs and remove the remaining screws that are into the truss.
He said if you have a sprayed ceiling and you don't want to remove screws into that 2x4 above you could pull the nails and let the 2x4 float too.

This doesn't sound like fun but the drywall would be one with the lower wall and the truss would be allowed to move up and down. for inspector, the walls could move up and down.

Thought?
Sure the walls will stay where they are, and the truss will move. But that only means the crack is not at the lower wall, the wall ceiling joint will give somewhere if you do not remove the ceiling screws at the edges.
And that only works if there is enough play, which there usually is not. This is why folks install pieces of floating trim at those joints.
The truss clips, {everyone never uses} are what is needed. Then the wall is connected and floats with the truss.
 

nealtw

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Sure the walls will stay where they are, and the truss will move. But that only means the crack is not at the lower wall, the wall ceiling joint will give somewhere if you do not remove the ceiling screws at the edges.
And that only works if there is enough play, which there usually is not. This is why folks install pieces of floating trim at those joints.
The truss clips, {everyone never uses} are what is needed. Then the wall is connected and floats with the truss.
This us how they want the built before they drywall.
Even if it is tight and the drywall is only screwed to the studs, the back of the drywall will be scuffed.
The ceiling would be a concern, I think you are right, about removing screws there if there are any.
 
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