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Single Family Home Precast Floors

jar546

jar546

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The slab is poured but for the 2nd and 3rd floor they will be using these for this SFR to increase the speed of construction. Anyone else use these?
IMG_4725.JPG
 
I've seen them used a lot in commercial buildings, especially hotels, but never in a residential setting. They certainly would make a good solid floor for residential and would greatly reduce noise transmission from floor to floor.
 
We see them occasionally for garages in SFR to create a basement for the garage. Most of the time it is for houses on the river to give them a place to lug in their canoes, kayaks, etc.
 
Msradell said:
I've seen them used a lot in commercial buildings, especially hotels, but never in a residential setting. They certainly would make a good solid floor for residential and would greatly reduce noise transmission from floor to floor.
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If you use sound attenuation below your tile and hardwood.
 
Do they have some camber built into them? They don't appear to have a T&G connection?
 
Pcinspector1 said:
They don't appear to have a T&G connection?
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If you look closely you can see a bit of a rounded recess in the edge of the precast. They probably set them in place, caulk the bottom of the joint, and fill the gap with high strength grout. If there was a traditional t&g on the edges, the installers would have to be sure not to get two T’s or two G’s together ... this way the precast is omnidirectional.
 
e hilton said:
If you look closely you can see a bit of a rounded recess in the edge of the precast. They probably set them in place, caulk the bottom of the joint, and fill the gap with high strength grout. If there was a traditional t&g on the edges, the installers would have to be sure not to get two T’s or two G’s together ... this way the precast is omnidirectional.
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Careful with longer spans as they can bounce depending on weight applied.
 
We used them once many moons ago in a house for a German doctor who wanted it built SOLID the way they do in Germany. The main problem we ran into was that some of the strands got cut when they core drilled for plumbing. I'm guessing there were a couple extra strands because we didn't notice any structural distress afterwards.
 
Paul Sweet said:
I'm guessing there were a couple extra strands because we didn't notice any structural distress afterwards.
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Looking at the picture, i only see a strand at the bottom of the webs. So if you located the hollows and drilled there it shouldnt be a problem.
The plumber is going to need something stronger than a sawzall.
 
Paul Sweet said:
I'm guessing there were a couple extra strands because we didn't notice any structural distress afterwards.
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Sorry ... don’t know how to edit a reply after it is posted.
The concrete units might not have prestressing tendons. Not all precast concrete is prestressed, or post-stressed.
 
In my limited experience,

These are pre-stressed. They are cast with a bow in the center to allow them to settle level, the space between the panels is stuffed with a backing material and a top coat of concrete applied over top, because the people who can afford this type of thing in their garage/house will not accept having those beveled edges. If there is coring or drilling, they should be factory installed (precast). site modification of the panel is a huge no-no. An engineer is required on each project not just for the panel, but the wall supporting it as well.
 
tmurray said:
These are pre-stressed. They are cast with a bow in the center to allow them to settle level, the space between the panels is stuffed with a backing material and a top coat of concrete applied over top, because the people who can afford this type of thing in their garage/house will not accept having those beveled edges. If there is coring or drilling, they should be factory installed (precast). site modification of the panel is a huge no-no. An engineer is required on each project not just for the panel, but the wall supporting it as well.
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Now we're cooking, so there's an engineer involved, I thought so.

So there should be an arrow saying this side up ^. Probably some paperwork for Jar to read...I would think..
 
Pcinspector1 said:
Now we're cooking, so there's an engineer involved, I thought so.

So there should be an arrow saying this side up ^. Probably some paperwork for Jar to read...I would think..
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We get stamped plans and the factory turning these out sends a crew to do the installation. Our subdivision inspector actually used to do this. He is an invaluable source of information on these.

Walls here are a reinforced concrete wall (CMU is not typical for residential construction in Canada). Typical reinforcement is 2 rebar mats 15M at 12" vertical and horizontal.
 
tmurray,

I clicked on your like button, cuz you explained what 15M means, but that does not mean I like the metric system!
 
Right ... 15 mm = 0.59” ... #5.5 rebar. So how does that work? The rebar i see has the size molded in with the ribs ... whole numbers ... surely there isn't a separate rebar mill for metric sizes.
 
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