Home on elevated concrete slab?

[pattyw]

I am trying to model my home which needs to be elevated.  I will have piles in the ground with a pile cap on top and a grade beam connecting the pile caps.  There will be a floating ground floor slab not supported by the piles.  I am then trying to model 10' high square concrete columns that would support an elevated concrete slab.  Then I would start modelling the main house (ICF walls).  I'm having trouble with the columns and elevated slab.

 

1) How should I model the pile caps and grade beam?

2)  The ground floor will have breakaway walls between the columns.  I can model the ground floors walls but then don't know how to get columns into it.

3) How should I model the elevated concrete slab?  There will be tie beams connecting the top of the columns with a concrete slab between them. 

4) What if I wanted to model that 1st elevated concrete slab using composite steel decking like say ComSlab or Vulcan?  or something like InsulDeck?

 

Here is a pic of an elevated slab using Insuldeck.  Does this software support modelling this? 

 

 

 

 

Thank you

 

2021 Home Designer Pro

[solver]

Do you intend to submit your plans as construction documents for permitting, or are you simply wanting a visual representation of the house?

 

 

[pattyw]

I already have enough in the computer for a visual representation, but take offs, cross sections, etc are not accurate.  I was originally hoping to hand over my rough drafts for a draftsman to officially draw up, but so far they are all 3-6 months out so now I am now hoping to just do all the drawings myself and submit for permitting and hopefully I can find an engineer to review my drawings.

[solver]

You will certainly need an engineer to design the structural -- columns, beams and slab, so why not let them do the work? For a house like this, you really need a team -- you, your builder and an engineer working together.

[pattyw]

Thank you, I know I need an engineer.  I plan to GC the house myself.  I just don't want to wait 3-6 months for somebody to draw something for the engineer to approve. Also don't understand some of them telling me once they do start it could still take another few months.  I've already designed the house.  I don't think it should take months to figure out exactly what rebar we're going to put into the columns and slab. I don't need an architect, just somebody to draw and an engineer.   I have an engineering degree and understand enough about this construction that I'd like to think I have enough knowledge to draw it.  A big part of this design is just looking up stuff in various tables checking spans and loads to know how wide, tall, how much rebar, stirrup spacing, etc .  After the engineer reviews, if they want me to tweak a dimension or two or clarify in some cross section drawing the rebar or change what rebar, etc, I'm not worried about that.  In searching through building permits online for similar construction nearby, I see a lot of the construction and sub details are the same, really feels like a lot of these engineers just tape predefined cross sections to the drawings and add a few notes.  The other reason I'm getting more involved in the engineering is on advice from others that GCd similar construction themselves and to not just trust every single thing from the engineer and be careful I don't end up with a way over engineered (and more costly) house so I do want to understand the why about every decision that goes into it.

 

I figure I'd put a few weeks into trying to draw this all myself, including all the various cross sections, notes, etc and see if I can find an engineer to look at them.  All I have to loose right now is my own time and setting me back another few weeks.

 

The question is can this software handle this house? 

[solver]

2 hours ago, pattyw said:

The question is can this software handle this house? 

 

Probably. The key is learning the tools the program provides, and then using them to create the model. If you have a good understanding of the program, you may be able to use its automated tools to do some of this, but even then I suspect much manual work.

 

You will need details for all the rebar and anything the program does not do, like the floor system you described above.

 

 

18 hours ago, pattyw said:

 

1) How should I model the pile caps and grade beam?

 

I don't really understand this question. The program has no concept of a pile cap , so you use the best tool (Soffit, Slab, Shape from the library etc) to model it. Then create a detail to explain what it represents. The foundation builder has a Grade Beam on Piers option that you might review.

 

18 hours ago, pattyw said:

2)  The ground floor will have breakaway walls between the columns.  I can model the ground floors walls but then don't know how to get columns into it.

 

It depends on the assembly. Railing walls can automatically include columns, and Panels might work for the breakaway parts. You can place columns independently as you wish too.

 

18 hours ago, pattyw said:

3) How should I model the elevated concrete slab?  There will be tie beams connecting the top of the columns with a concrete slab between them. 

 

As it will be built.

 

18 hours ago, pattyw said:

4) What if I wanted to model that 1st elevated concrete slab using composite steel decking like say ComSlab or Vulcan?  or something like InsulDeck?

 

Using a detail drawing is your best bet here. 

 

If you know SketchUp or another similar program, you could create symbols and import, manually placing them to represent these options.

[pattyw]

So I've been playing around for a month now and have made great progress but always some little details.

 

I tried your idea of using a rail and while I got it to kind of work it was very inflexible.  It didn't draw the columns on the plan and I couldn't place the columns were I wanted to.

 

For the piles and grade beam, what I've found is to NOT use the applications built in grade beam on pier feature.  Here in florida in VE and AE zones it's very common to have a grade beam on piles, but then also a stem wall on top of the grade beam.  When using the built in grade beam on pier feature, I was not able to have the slab be above the grade beam.  So I switched to a wall with footing and I am treating that footing as the grade beam and it has the dimensions for the grade beam.  I then manually place cylinder objects beneath the grade beam for the piles.

 

For the ground floor walls and tie beams, I found an online tutorial for doing that with a pony wall and it does work nicely.  Although, ..., my tie beams are 24" wide and the pony wall beneath it is only 6" or 8" depending on that wall type.  I did use the align pony wall features, but it would be nice if you allowed a custom offset. I don't want it aligned with the outside or the center.  It will be almost to the outside but inset a inch or two. I tried to create an exterior air gap later in the wall types but it insists on rendering that outermost layer. Don't see a way to create an artificial layer in the wall type to offset how it's drawn.

 

For the columns I just manually place a square shape over the walls.  Don't see a way to attach additional materials to that like the rebar needed.  This is assuming a cast in place column.  Another approach is to make a 16x16 column using blocks.  I tried making the wall extra thick, two walls side by side, etc, but wasn't making progress with that approach either.

 

Next up will be that elevated slab on top of the tie beam!