PT 2: 2024 Garage Build – Plans

Getting an official Plan Set made

With the preliminary sketch in hand, I began to look for the next step. I experimented with Revit, even coming up with a workable plan for a simple garage. However, I was not comfortable drawing these plans myself due to the complexity. Attaching to my existing home really increased the difficulty. Additionally, with the second floor living space a simple truss based design would not adequately cover the loading calculations. A structural engineer was definitely required. I am an “engineer”, but not the kind certified to do structural plans. I decided to hire this part of the job out.

What I should have done was hire my neighbor to help. As it turns out, he used to be a draftsman/designer/custom home builder. He is currently an insurance agent. I knew this at the time, however I didn’t want to burden my neighbor or cause any issues close to home. I imagine I would have gotten a better product for significantly less money. After the project was built, he came by and chatted with me, very complimentary, and asked about it. He would have been more than willing to help with no issue – so my loss there.
Alternatively, there is a company local called Cider House Studio that does house plans for a really fair price. I contacted them and even got a quote to work on the project, but ended up not choosing to go with them. They don’t do engineering, however they have a partnership with an independent structural engineer who would stamp the plans.
Because of the separation of responsibilities, I was concerned about this path.

Instead, I hired the wrong company, they took longer than promised, had little attention to detail, and made a couple of errors that ended up costing me time and money down the road. In the end, the plans did get approved and the building is standing, so this is documentation of lessons learned.

The final plans received from the Engineer are at the bottom of this post. Initial consultation invoice paid 11Jan2024, Final Plans received 12Jun2024 – Actual Project duration 6 months and 1 day.

—— If you don’t want to hear me complaining about issues I encountered, I recommend skipping this section. ——

The next few paragraphs are pure moaning and offer no tech insight or useful information.
Its word barf, so you are warned.

This section can be summed up as:

Bait and Switch

I chose to hire a well-regarded local engineering firm “JDS Consulting” to make my plans. Upon initial contact, a representative told me a reasonable price for the work – $2000. The first step would be scheduling a site visit, where they would laser scan (in 2d) my house and perform a site assessment, for $400.

In the first of many issues, after the site visit was paid for and completed, the company came back and told me the job would actually cost significantly more. The Price quote was initially $7500. Obviously this is not what I was expecting, or I would not have gone down this path. I had already sunk the $400 into the site visit however, and delayed my job over a month waiting on the site visit + assessment, so some “sunk cost fallacy” was on the mind.

I did call and have a conversation with the manager, who reached out after a couple of unpleasant emails between myself and the sales rep, in which I requested a refund on my $400 due to the “bait and switch” pricing. What I should have done is cut my loss and move on. However, the manager got me with some smooth talk. I remember clearly asking him if I would receive high quality service and a good deliverable after the initial issues we were having, including the unpleasant conversation I was currently having. I was assured that regardless, I would receive the same “great” service as all customers. He offered to do the job at a lower cost as a good faith effort to work with me due to the misunderstanding. The agreed upon cost ended up at $5500. This was all verbal over the phone so I do not have written records of the conversation.

Schedule

I relented, and agreed to use JDS to complete my plans. The agreement was signed on 01Feb, and the start date for my job was stated as 11Mar with a 4 week turnaround. The initial payment was submitted on 08Feb. Due to my agreement for lower cost, I was warned that no changes would be permitted to the plans, and no site visits would be included moving forward. Fine by me, as I was committed to what I wanted at this time, I just needed a bit of help getting the proportions correct and ensuring the structural analysis was sound. With JDS having the detailed sketches seen in Post 1, I did not expect any issue converting to CAD and aligning with what we wanted layout wise.

Then we went radio silent for a long time. The stated 11Mar start date came and went with no communication. After a week, I sent an email asking if everything was OK and got a response! They did start on time, and preliminary plans would be forthcoming within a few days. Great! So I waited another week, then another, with no response. It was now 03 April, close to the proposed end date for the project, and I did not even have a preliminary set. So I sent another email.

Design Gaps

The next day, the prelim set arrived, and Immediately there were issues. The majority boil down to minimal attention to detail – Like doorways not lining up, generic “details” sections for features not necessary on my plans, etc. The major issue however was the ceiling height not meeting the specified minimum (12’3″), discussed as a firm requirement to allow lift use. In addition, there were a few more things that organically came up, requiring some back-and-forth discussion and decisions to be made. Examples would be placement of interior doors, door swings, and how to resolve the anticipated window issue on the existing bonus room’s south wall.

This continued on throughout the entirety of April, and the First 2 weeks of May. I would send a response with decisions, and get nothing for a couple of days. After getting a corrected set with some more questions, I would respond within 24 hours, and get nothing for a few more days. Fine, at this point I was being patient, but beginning to get upset.

Final Hurdles

We eventually got down to two final issues, the ceiling height, which centered around the design of the foundation wall design and slab construction, and the slope of the slab itself (drainage related).

Foundation Wall and Ceiling Height

The foundation wall design presented two separate issues. The first was ceiling height. I required from the beginning a minimum of 12′, with preference of 12’3″ to facilitate a wide range of 2-post lift brands. I eventually figured out that the designer was reference the distance between the top of the foundation wall to the bottom of the second floor joists as his “ceiling height” dimension. For me, this dimension was not relevant – I only cared about the top of the slab to the bottom of the drywall.
The second issue was the usable floor space available, affected significantly based on the choice of foundation wall design. The original block foundation wall would result in a block wall coming up between 8″ and 1′ and being 8″ thick, then reducing down to a regular 5.5″ thick wall (2×6 construction). This would result in toolboxes, cabinets, benches, etc. having a 3″ offset from the wall above the first foot, wasting usable space (6″ total if you include both sides), creating a void for debris and bugs to accumulate, and reducing the stability of tall furniture.

This was obviously not desirable, so I pushed back for a different solution. I was asking about alternative options when the change to a Monolithic slab with integral curb was presented. It finally came down to a discussion of options, in which the various types of CMU (Concrete Masonry Unit) block designs were compared, along with a short pure concrete poured curb. During this discussion, it also was pointed out that going to a Monolithic Slab would be potentially cheaper to build!
Well duh, why did we not start with the cheaper option, which also increased floor space? I can’t possibly say, but we got there eventually. Now I just needed to get a clear section drawing of this detail, so I can ensure its built to design.

Turns out, that was harder than expected. It took at least 3 more revisions, including one that was sent for “stamping” by mistake before my agreement, before I got something workable with a section drawing illustrating this feature in enough detail I could get it constructed.

Slope

Most of the end of May was spent bickering with the engineer(s) about the slope of the slab. Now you might not think slope is a big deal, but in my case it’s important for two reasons:
1. Lift install
2. Corner Balancing

Lift Install

I want to buy a lift that has the lowest possible pads, to allow lowered cars to be easily lifted. If you have ever used a lift installed on poorly sloped concrete, or tried to lift a lowered car, you will understand.

If the lift is on concrete sloped 1/8 per foot (the engineer’s proposal), the front of the front lift arm, and the rear of the rear lift arm, would easily be an entire inch different in elevation.
To install the lift correctly, its columns must be straight up and down. Therefore, the back (door side) of the lift column gets washers or shims to offset any concrete slope. If the front side was touching the concrete (Not shimmed), now when you try to swing the forward arm out front ways to the “storage” location when a car is not lifted, it will hit the concrete! So you must shim both the front and back of the lift base plate. This reduces surface contact with the concrete (which is strong in compression only), and adds height to the lift arms. If the front and back arms are 8′ apart when straight out, this means the rear arm will be a full inch off the ground at the back, and that’s a lot when we are taking about ride height for race cars.

Corner Balancing

I plan to perform setup for track use on my personal and customer cars in this space. To do so, I will need to establish a location with maximum flatness, and shim my scales appropriately to ensure they are all level and don’t influence the setup of the car. In this application, even 1/8″ over the wheelbase of the car is important.

For anyone who doesn’t understand the process, you place all 4 corners of a vehicle on scales to measure the weight. Then you adjust the height at different corners, as well as re-arranging weight within the vehicle if possible, to balance out the car. With “Coil-overs”, you can spin the adjusters to directly increase or decrease ride height. With other suspensions, shims or blocks can be added to change the balance.
The target is to get 50/50 cross weight – meaning the front left + right rear, and rear left + right front have the same totals. This will help the car perform equally in both left and right hand maneuvers.

In order to do this successfully, you must ensure all 4 scales are exactly level. Otherwise the small slope will change the weight balance of the car and reduce the effectiveness. If you are at the track and see small circles or squares painted/taped in the garages or paddock, I’d bet its from a pro-team using its scales onsite and ensuring the base plates remain stationary through the weekend once they level them. To do this in a garage, you use a laser level to establish a level square at each contact patch location. I have seen people use LVL tiles, wood, cardboard, paper, and many other commonly available materials. Pro race teams use leveling squares sold by the scale manufactures (for example, Longacre).

Finding a Compromise

Having 1/8 per foot of concrete slope designed into the slab was not acceptable to me. I know that concrete is an imperfect surface, and I expect some small variations in surface slope after construction, but I didn’t want to intentionally add slope. I worked hard to ensure this was not part of the original design.

After getting the initial set of “stamped” plans, I had some feedback about the slab. The concrete thickness and specified compressive test were not aligned with what was specified in my initial sketch provided to the engineer. The plan also called for welded wire fabric (WWF). I did not specify or want WWF. When drilling the holes to install a lift, hitting steel is a problem. Rebar needs to be carefully placed to ensure the lift can go in without hitting the steel. With WWF, the mesh is so tight that this becomes impossible. I also feel WWF is less effective, as when pouring the slab it gets stepped on and pushed to the bottom. All of this was specified in my initial sketch, but somehow got overlooked.

At first, the engineers refused to issue a drawing set without slope specified. The engineer’s opinion was formed around the slope being a code requirement per R309.1 and being a life safety issue. The stated opinion was “the slope is intended to slope out hazardous chemicals” – That really confused me.

My initial suggestion was to rename the area in question. The code above is non-specific in its requirement – it doesn’t specify a minimum slope. If the downstairs area was referred to as a “shop” or a “storage”, it would no longer be subject to Section R309 and the loosely defined requirement above.
I would also like to note that I suggested at this time an issue with the naming of the upstairs rooms as “office”, which is specifically called out as forbidden by Wake County – this will come up again down the road.

The engineering firm did discuss my suggestion, but the final decision was to reject my idea. The justification being that the space is accessible by a driveway, and the doors are large enough to accommodate cars. They also provided a NC Department of Insurance letter regarding a case which referenced the definition of a Garage. I have attached this document for reference.

Solution

Knowing that the renaming was off of the table, I really had to think of a solution. After a couple cups of coffee, this is what I came up with: Liability coverage via Ambiguity

Instead of specifying the slope, the engineers could just specify “slope” which is in perfect synchrony with the code requirement. At the time of construction, it would be up to me as the owner and foreman to construct the slab within the defined limits. I am able to specify any slope I would desire, such as 0.0000001 in/ft.

This was accepted by the Engineering firm, and the plans were re-stamped with the updates.
The final plans were not received until 12Jun, a full 2 months behind. AT least they were finally done!!!! (foreshadowing…)

—— End of ranting, now back to some reasonably useful information in the next post ——

These are the pans turned over by JDS Consulting on 12Jun2024.