Squash blocks detailing for concentrated loads on trussed floors

[Bammer25]

Hey guys

Curious how you detail out carrying large (for residential sake) point loads from roofs or lvls above when your floors are trussed.

Adding a squash block is pretty simple and they will just block it out, but when you are relying on a 6x6 or PSL to carry the vertical load you’re just not going to get there with that method. Trusses simplify things for sure but I am getting to where I prefer designing stick building everything (including the floors) so I can control this better.

 

[XR250]

Trusses simplify things for sure but I am getting to where I prefer designing stick building everything (including the floors) so I can control this better.

Same.

Adding a squash block is pretty simple and they will just block it out, but when you are relying on a 6x6 or PSL to carry the vertical load you’re just not going to get there with that method.

Why not if you fully support the area of the post?

 

[Bammer25]

Same.

Why not if you fully support the area of the post?

As in having jacks come up on both sides of the truss?

 

[XR250]

Yes

 

[GaStruct]

Hey guys

Curious how you detail out carrying large (for residential sake) point loads from roofs or lvls above when your floors are trussed.

Adding a squash block is pretty simple and they will just block it out, but when you are relying on a 6x6 or PSL to carry the vertical load you’re just not going to get there with that method. Trusses simplify things for sure but I am getting to where I prefer designing stick building everything (including the floors) so I can control this better.

I agree with what XR250 said above about full bearing squash blocks. Not a complicated solution, but, I don't see a lot of contractors chasing point loads unfortunately. Something to consider.

Regarding specifying 2x....contractors in my area despise this because of MEP. Structurally, it's hard to beat the allowable spans of engineered framing.

 

[XR250]

Regarding specifying 2x....contractors in my area despise this because of MEP. Structurally, it's hard to beat the allowable spans of engineered framing.

Funny, around here, most are the opposite.

 

[GaStruct]

Funny, around here, most are the opposite.

Interesting....Soffits and drop ceilings? Split systems?

 

[jayrod12]

When I've done trussed roofs and floors, I plan out my girder post locations such that I don't have large point loads coming down onto trussed areas below. If unavoidable, then there's no truss, I switch it to a beam.

 

[XR250]

Interesting....Soffits and drop ceilings? Split systems?

Mostly try to use 2 HVAC systems or have a chase going up to the attic to feed the second story.

 

[RontheRedneck]

I see plans all the time that say something like "solid blocking under girders down to the foundation". So I don't see what the issue is.

 

[jerseyshore]

I see plans all the time that say something like "solid blocking under girders down to the foundation". So I don't see what the issue is.

We have a somewhat similar note on all of our plans and I've never had a problem on 6 story buildings or single family houses with trusses.

Just like anything else, our plans are only as good as the framer(s) putting the stuff in.

 

[rlmengineer]

I would ensure the column doesn’t fall on a floor truss. Cut out the subfloor and support the column on a footing or pier. Unless the floor truss was designed to carry a concentrated column load your going to cause a localized dip in the subfloor.

 

[XR250]

I would ensure the column doesn’t fall on a floor truss. Cut out the subfloor and support the column on a footing or pier. Unless the floor truss was designed to carry a concentrated column load your going to cause a localized dip in the subfloor.

I am pretty sure he meant that he had support below truss also.

On a similar note, ran into this on a job yesterday...
This is a girder roof truss carrying floor and roof loads. 8.5k computed design reaction. Nothing under it in the foundation except a floor truss! The whole center of the house was down 1" as the load was trying to go other places.