AirstreamJake

Perimeter Masonry Piers on Grade Beam Foundation

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Hello,

 

I am trying to create a foundation for my home that will consist of perimeter and interior CMU (block) piers.  This is a extremely common type of foundation in the south, but one which does not seem to be easily accommodated in Home Designer (Pro version, in my case).  It is not one of the three foundation types among which one must choose in the Default Options panel.

 

See the one-page 'Raised Floor Foundation Guide' which I've attached below for pictures of the structure of the foundation I am trying to create.  On my home, the perimeter CMU piers will rest upon either a continuous concrete grade beam or on concrete spot footings (see pictures in attachment).  On top of each CMU block pier will be a perimeter beam (girder) consisting of two 1-3/4" x 11-7/8" LVL.  On top of the girder will rest the floor platform (rim board and I-beam joists, etc).  The floor joists will be supported in the interior of the structure by LVL girders resting on CMU piers on spot footings.

 

Does anyone have any direction for me as to how I can get started in producing this type of foundation plan in Home Designer?  Any help or pointers would be greatly appreciated.

Raised Floor Foundation Guide.pdf

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What's not working for you?

 

Posting a plan that represents your best effort will give others something to start with.

 

The software will not build this type of foundation automatically, so you will need to create and place any piers, and possibly some of the framing.

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Solver, I am working on such a plan now, and I will post it as soon as I have worked through to my best solution.

 

A comment though, admittedly made out of frustration.  Having spent $600 for design software that is marketed to non-professionals (i.e., I didn't purchase from their more advanced software line), it is disappointing to say the least to find that the software can't readily and easily handle one of the most common foundation types in the South.  Homes have been built in the way I describe here for hundreds of years, and still today, the 'wooden beams on concrete block piers' are probably the most common foundation type other than slab (in the south anyway, where we don't have basements).  Why in the world could this type of foundation not be automatically generated, without each new Home Designer user having to reinvent the wheel?  Just venting.

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Attached below is my best shot thus far at getting the house to sit on CMU piers, as I desire.  However, as you can see, there is no framed platform (sill plate, floor joists, rim joists) for the first floor.  Can anyone give me any ideas on where to go from here?

House on Piers.plan

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Start by building a stemwall foundation. That will get your floor platform. Then delete the foundation walls.

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Eric, thanks for once again getting me over the hump.

 

I had tried using a slab-type foundation, then deleting the slab, but that of course was not the right approach (which, in hindsight, is obvious).  Your suggestion was spot on.

 

I'm now trying to get the pillar height correct (as can be seen on the plan below), but I've looked through all the options on the menu and can't seem to find the height of the floor to which the pillars need to reach.  I know it's got to be a simple thing to do, but I've looked everywhere and can't find what I need.

 

House on Piers.plan

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In a framing overview, select the framing member that's above the pillar and open it. It will give you its dimensions -- elevation of the top and bottom etc.

 

Set the top of your pillar to equal the bottom of the framing member.

 

You can do the same thing by taking a cross section and using the dimension tools to measure.

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Okay, that worked.  However, I expected that the lowest framing member would be the sill plate; however, it appears the sill plate is missing and so the lowest framing member is the rim joist.  How do I get a sill plate in there if it didn't automatically generate?  Also, there is a gap (see plan) between the wall base plate and the floor joists (see attached plan).  Is that just how the program displays things in framing view, or is there a true gap there?  Is the gap caused by the missing sill plate?

House on Piers.plan

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You will need to manually draw it. Use a joist and resize it.

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14 minutes ago, AirstreamJake said:

Also, there is a gap (see plan) between the wall base plate and the floor joists (see attached plan).  Is that just how the program displays things in framing view, or is there a true gap there? 

 

Are you asking about the gap between the wall and floor framing? Turn on the Floor Surfaces layer.

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Hi Eric - all of this was extremely helpful, and I literally couldn't have done it without your input.  I've now got the sample house sitting properly on the piers and with the newly-created sill plate inserted between the piers and joists (see attached plan - mainly for future readers of this post).  Your suggestion to turn on the Floor Layer display also fixed the air gap that I was seeing between the wall base plate and the floor joists.  It's a learning process, but I think I've now got what I need to start applying this to my actual house plan.

 

I only have two remaining problems, minor and I can work around if needed:

(1).  Since my piers and footers are an architectural block, I can't get the piers themselves to snap to the CAD lines outlining the foundation.  Instead, it snaps to the widest part of the architectural block; i.e., the footers, and

(2).  Since my sill plate is really a transformed floor joist, the program still identifies it as a floor joist and not as a sill plate.  No big deal, but is there a way to predesignate it such that the program realizes it's really a sill plate?

 

Thanks for getting me to the point that I can add in my piers on my plan.  I've got a concrete guy coming out tomorrow to give me a quote so I can get the foundation underway, and I was getting concerned that I wouldn't be ready for him! 

House on Piers.plan

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5 hours ago, AirstreamJake said:

Since my piers and footers are an architectural block, I can't get the piers themselves to snap to the CAD lines outlining the foundation.

 

I'll use CAD lines, and center the block on them.

 

5 hours ago, AirstreamJake said:

Since my sill plate is really a transformed floor joist, the program still identifies it as a floor joist and not as a sill plate.  No big deal, but is there a way to predesignate it such that the program realizes it's really a sill plate?

 

Guessing you are referring to the material list? Not positive, but I don't believe there is a way to change.

 

In my experience, you don't use a continuous sill when building over piers. Just a single block of treated material on top of each pier.

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Eric - thanks for walking me through this.  I completed adding the pier foundation to my plan today, just in time for the concrete guy to provide an estimate tomorrow.  You are correct, the sill plate is usually not continuous but, for purposes of my plan, I've left it there for now while working on the piers.

 

To help others out in the future, I've attached a 3D image of my house plan on CMU piers.  I still need to add the beams between the sill plates and the floor joists, but that's a job for another day.

1229 SF - House Plan on Piers.stl

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