Foundation Plugin


This brings to mind something I saw on a construction site a couple years ago. A contractor was framing up a garage wall and one of the anchor bolts landed exactly in the middle of one of the wall studs. A big V-shaped notched was removed from the bottom of the stud, to the point that the bearing strength of that stud was severely compromised. A 3.5" sill plate also leads to situations like this:


A good builder would give it much thought. I know that I’ve given thought to the code requirement, joist layout and also foundation vents, not to mention where the anchor falls in the mortar joint of the cap blocks. These things combined probably require a few more anchors than the code requirement.

The straps shown in the post above do avoid some of these items but likely are not acceptable in all seismic zones or even all local codes.



To me , fixing that bottom sill plate with such oversized anchor bolts seems totally weird, the only thing it is holding is the bottom sill plate, because , usually , the wall framing is only fixed on the sill plate with a few screws , or nails.
Better extend the anchor bolts to the top sill:)


The 1/2" and 5/8" anchor bolts, washers and some standard nuts.

View models here:



I like the way you did the threads in your drawing. Reducing the circle used for the bolt hole and bolt from 24 sides to 6, 8, or 12 reduces the entity count by factors of 6, 3, and 2. Though the appearance of the 6 sided bolts is a bit crude for sure…

I did a quick drawing borrowing your original just to show myself what they would look like.

All the best,
Charles Sloane


I learned that little trick with the threads from my working with Solidworks. They call it a cosmetic thread. The idea is to try and create the appearance of threads with a material but maintain the lightweight model but not actually modeling the threads. By creating another circle bisecting the solid and the surface I can then apply the thread material to the threaded portion. I adjust the thread pitch by adjusting the scaling of the material in its material properties. The height is the inverse of the threads per inch.


So I’ve loaded three components (sketchup files) from my components folder, a bolt, washer and nut and now I want to combine them all into one component, any hints?


Version 1.0.7 - 03.19.2017

  • Added 1/2" and 5/8" Dia. Anchor Bolt option to stemwall and slab on grade foundations.
  • Anchor bolt lengths are nominal 10", 12" and 14", square washers are 2"x2" or 3"x3".

View model here:

The anchor bolt, washer and nut are three separate files that are loaded in as components. Then the nut and washer components are inserted inside the bolt component and exploded so only the solid group(s) remain. Its pretty amazing what you can do with a robust API and a little bit of Ruby code.

It took me most of today to figure out how to do all of this since I’m in uncharted territory but now that I’ve got it kind of figured out it opens up the possibility for a host of other things (holdowns, windows, doors, vents etc…) for this plugin and the others I’m working on.


The cosmetic threads actually render quite nicely as does my rebar material/texture. I just realized I have not added any custom materials into the foundation plugin.

As you can see from the image the orientation of the J-bolts is the same regardless of the wall, however it would not be a couple more lines of code to orient them all facing in or facing out or some other combination. Curious how the contractors actually install these, is the orientation important


I’ve been talking to a few other contractors out there and most of them don’t pay alot of attention to the orientation of the J-bolts into the concrete, they let the concrete set up a bit and then stab them in.

I’m adding in the custom materials, stemwall foundation below is an example:

I will need to roll another revision probably tomorrow to get this update out there.

I was wondering about adding in the option for vents in the stemwall, for foundations with crawlspaces. Any thoughts on this and what is standard construction in your locale as well as what type/brand of foundation vents/inserts are used.


The ICC codes call out a minimum of a one vent within 3 feet of each corner. It shouldn’t be to much trouble to create the openings in the stemwall and place some vents:

For a rectangular building (4 sides) should I place 4 vents or 8 vents? Provide only the openings or also provide a generic foundation vent (lightweight geometry?)

Moving an opening is actually very easy within SketchUp, when it comes to a solid wall like this.

What is the typical header thickness between the top of the vent hole and the top of foundation?

Vent size seems to be 16"x8" for most vents I’ve seen.

With regards to vents there are the cheap plastic ones you can get a Home Depot or Lowes and and then there are a whole ton of more expensive louvered metal manufacturers of vents and flood vents.


The options for the vents will be:

1.) Width (in.)
2.) Length (in.)
3.) Corner Distance (ft.)
4.) Top Fnd. Distance (in.)
5.) Max. Spacing (ft.)
6.) Location: All Walls|Left/Right Walls|Front/Back Walls

The Max. spacing variable will determine whether to insert intermediate vents along the wall line. The module will always place two vents per wall (if wall line selected), one at each corner and then equally space vents along wall line based on the Max. spacing variable.


I just realized that I created the anchor bolts in SU2017, this could be a problem for users of previous version of SU. What is the best way to convert SU files/components into previous versions?


Best way is to save as (File>save as) and then select an early version of SketchUp.


Thank-you I didn’t even know that was an option, somehow missed that. I will give that a try.


The vent module seems to be working fairly well:

If you set the top distance to zero the vents are right up to the sill plate:

Notice the top bar is clashing with the vent cutouts.



If the ICC only requires 1 vent within 3’ of the corner, does this mean on each wall segment near the corner (i.e. 2 per corner), or on any one wall segment, as long as it is within 3’ of the corner. So that a smallish square foundation would only need 4 vents, not 8? Not that I have studied the ICC any time lately…

Nice work.

All the best,
Charles Sloane


My understanding is you only need one vent per corner so yes, 4 vents on a small square/rectangle foundation. The number of vents is also driven by the square footage of the crawl space and the net free air of the vents, a simple calculation.


Version 1.0.8 - 03.23.2017

  • Added crawlspace vent option to stemwall foundations.
  • Added a “Materials” tab within the global settings; Auto material assigment (colors and textures) is now an option.
  • Enabled materials for all foundation types.


I think I’ve fixed the bug, download version 1.0.8 again and reinstall, the previous version is broken.