Homeowner DIY (possibly) - city inspector asking for "stamped" plan - willing to pay for help

rbtreml

Hello - I've been lurking in the forums for quite some time as I've slowly started renovating/adding onto a home in the Twin Cities area of Minnesota. The original home is a 1954 cabin (about 1000 sq ft on slab), a two story addition was added in the early/mid 80s (about 800 st ft - small crawl space and boiler room below), and I'm in the process of adding an attached garage with a bonus room above (an additional ~550 sq ft of livable space, 550 sq ft of garage). Total livable sq footage of about 2350 st ft, 2900 if you include the garage.

There's a long, messy story about a bad general contractor experience (since fired) that is only relevant in the sense that the city inspectors are now extremely heightened to the renovation work. They are unwilling to sign-off on the plan I've provided to retrofit the existing home and build the new addition with in-floor pex radiant floor heat using the existing boiler. They want an HVAC contractor or licensed Mechanical Engineer to sign-off/stamp the idea. Is there anyone on the forum that would be interested in giving me a hand (I'm more than willing to compensate - only stipulation is the Minnesota license thing).

More details - sorry for the length:
The boiler is about 10 years old (Smith GBX-105 - says 80k BTU/Hr output, https://literature.mestek.com/dms/SmithCastIronBoilers/GBXIOM-4.pdf). There is an existing Taco pump on a closed 2 zone system that covered the baseboard heat in the original home + 1980s addition (I don't have the technical details handy right now, but can definitely get them when necessary).

I had a local HVAC company create a new secondary loop off the existing boiler that feeds via 1" copper into a Cross Manifold (8 zone http://www.crossmanifold.com/cross-8/). Included in that loop is a mixing valve and as a GroundFos Alpha2 pump (max 21 GPM, Max 19 ft head). The intent was for the Cross 8 manifold to provide 5 zones: main living/kitchen area (~875 sq ft - 3 loops), downstairs bed/bath/office (~400 sq ft - 2 loops), upstairs bed/bath (~400 sq ft - 2 loops), new bonus room above garage (~550 sq ft - 2 loops), and the garage (~550 sq ft - 2 loops). I've run some high-level calculations to determine the heat needed for the bonus room and garage - based on the spray foam insulation and window/door info. Overall I'm coming up with around 60k BTU/hr required for the entire home.

Originally the city inspector said I needed to show that the existing boiler could handle adding the new addition heat requirements and that the 1/2" pex I intend to run to each zone would be sufficient to provide enough fluid/heat for the new areas. I realize it's not ideal to run 1/2" for supply and return on long runs, but I think the max length from the manifold to any zone is around 30-40 feet, at which point I would then run loops/circuits within the zones that are of equal length and less than 300 feet. I provided some calculations regarding the approximate flow rate I anticipated for each zone, which I believe is under the max flow rate 1/2" is capable of providing. The city then countered and said something to the effect of "you haven't been able to provide the necessary pex pipe information for us to approve, you will need a licensed mechanical engineer to sign off on your plan." After I asked what I needed the ME to include so I could move things along more quickly, they added that they couldn't find anything about the brand of pex I'm using that tells them how long the supply/return runs could be, or how long the loops could be, etc. They said other pex manufacturers (like Uponor) have installation guides that explain the max loop length, flow, etc and if my brand of pex had that they may have been able to approve things. In my naive initial days of this reno plan, I bought Vevor O2 barrier radiant floor 1/2" pex (https://www.vevor.com/pex-tubing-c_10837/1-2-x-1000ft-pex-tubing-pex-pipe-oxygen-barrier-o2-evoh-red-radiant-floor-heat-p_010912625553). While I now realize a more common/well known brand may have led to less hassle, the Vevor does list this with what I believe are the typical ANSI, NSF, IAMPO certifications. Is it typical for inspectors to require the pex to have this type of guide to sign off on a system design? I'm curious if HVAC contractors use materials that all have that type of information provided in a detailed installation manual (given the number of pex manufacturers, I'm skeptical).

Anyway, any help would be appreciated. I started the construction of the addition in September of 2022 - with the contractor issues and the recent inspection/plan delays I'd really like to get past some of these barriers to I can finish this stupid house. Thanks.

EdTheHeaterMan

Any homeowner has the right to make repairs and additions to their home themselves if they are up to the job. That said, I added a 3 car garage to my property with a simple drawing with no load calculations on the roof rafters or the load bearing walls. It was basically a rectangle with 3 squares for garage doors on the front and the side looked like a house you would draw as a kid in grade school. The only difference was that it was a 1/4" = 1 foot scale drawing. I signed it in the lower right corner. That was enough for my building inspector in Dennis Twp. NJ. I believe that is all that is necessary.

You may want to call your State Building Code Official (the guy that oversees all the local code enforcement officials) or ask the building inspector that requested the document.Ask if there is anything in the code that states that a sealed set of drawings are required for the type and scope of your project. You may need to get the plans drawn up or you may not. But you can always blame the need for that information on a higher power, like the bank that is funding the project (even if there is no bank… but the higher power is your wife) You personally really don’t need this information but the higher power does, and you (the inspector) are the only guy that I can depend on to know where that information is. Any help you can give me in this would be greatly appreciated.

The idea is "it's going to cost more for those plans, so you need to explain this rule to the bank why as to why you need more money." Building inspectors can be very helpful if you can get on their good side. You need to understand that they are there for your safety and their job is important and you are eternally thankful and grateful for any helpful information they can provide for your safety.

That is the BS I used to give all the inspectors that came on my jobs. Less hassles that way. An I would always leave something undone like a missing switch place cover or the safety tube off of the relief valve so they could find something wrong to fee like that did their job. Have a piece of pipe ready to install that safety tube while they are there and they will most likely hand you the approval sticker then and there .

dko

Vevor is a reseller, you will have to e-mail them and ask for the submittal/spec sheets and the approval certifications. You will find the original manufacturer from those documents, it'll be one of the major manufacturers like Rifeng. Then use the documents from that company. Important to use e-mail so you have the paper trail.

You're going to have to hire and pay an engineer to draw and stamp. There is no way around it. No one is going to simply stamp your plan.

EdTheHeaterMan

Sometimes the building or plumbing inspector will give you some hoops to jump through to see if you know what you are doing. Once you get on his good side with some intelligent answers to his questions, then it will get easier. @ethicalpaul has just dealt with inspectors on his DIY Boiler job. Maybe he has some insight into the process.

dko

I assumed the inspector felt someone didn't know what they were doing and then required the stamp. So possibly

rbtreml

Thanks EdTheHeaterMan and dko. I appreciate the quick responses and feedback.

At this point, I am definitely looking for an engineer to stamp the plan (or even tell me my plan is idiotic and I need to reevaluate) - I thought I'd hit up this forum to see if anyone has any contacts or recommendations in Minnesota. Oddly enough, I have a degree in mechanical engineering from UW-Madison - but it's been almost 20 years since I held a true engineering job and that was in the tire industry. So I hold no licensure in MN and I'm admittedly new to the permit/inspection process in this municipality.

What frustrates me is the method the inspectors have taken to arrive to this recommendation - I'm not saying the final conclusion is wrong, just how we got here. I've had them out multiple times at this point due to the old general contractor causing numerous issues. They signed off on all of my (DIY after the GC screwed it up) plumbing work, reviewed the gas line update and boiler modifications + manifold done by the HVAC guys, "passed" the pressure test I had done on the entire Pex system/manifold, etc. They said nothing on that visit to lead me to believe they were questioning my approach - even a few "looks good" comments before leaving. So I'm a bit frustrated that now they are asking for more work to be done when I really want to get the new contractor moving on drywall, flooring, etc.

GGross

my neighborhood 2 sets of sealed plans are required prior to starting major remodels or new residential construction, they also want a manual J that is shown to be done in accordance with code acceptable practices, and they want a quick sketch of the proposed systems such as electrical HVAC plumbing, most contractors submit really nice looking plans. Sounds like you have maybe made the unfortunate choice to argue with the inspector, what they are asking for is reasonable. What you need to do is a manual J (load calc) for the entire house including any additions or remodels.

It is unclear if you are supplying a manifold with 1/2" pipe, or these are the infloor runs. If you are supplying the manifold with 1/2" pipe then anybody would question it, and you better have exact numbers to back up your claim because it just looks like someone is trying to cheap out. This would be a dumb thing to argue with an inspector about in my opinion, it would immediately flag you in my mind as a hack and I would not want to deal with it. You also can't just use 1/2" and say you aren't at the maximum allowable flow rates, there is also flow velocity to take into consideration, and the added pressure drop from the smaller tubing. Easy fix here is to upsize the supply and return, just be done with it, make it right, but now you need the actual numbers as well so get a design done and manual J

If you are just running the 1/2" in the floor for floor heating then they are correct that you need to show them a radiant design, which includes a manual J. They won't really need an HVAC contractor to sign off on it if you can show them that it will work, and back it up with documentation done in accordance with code acceptable practices

Daveinscranton

I would exhaust all possibilities on the DIY front. Many times life gets easier when the inspector/permitting bunch knows that you are competent.  And accountable.

 If diy, I suggest overkill on design.  The money saved elsewhere can be put back into better quality materials etc.

If you absolutely need stamped drawings, you need a friendly licensed engineer with a reasonable ego to redraw your plan.  I saved a huge amount of money by doing the calculations for the permitting process.  

delcrossv

Weird. Per @EdTheHeaterMan 's comments, the most static I got from the local building inspector was to use joists 12" on center forour addition because the house has 2x8 floor joists.

Once they saw the cast iron drains with poured seals my plumbing inspection was done. 🤣

You can always work on your own house.

EdTheHeaterMan

I did another addition on my own home where I asked a draftsman to take my drawing and put it on "Blueprint" type paper at the office where he worked. I gave him my detailed hand drawings. He was impressed at the accuracy of my plans on graph paper and the detail that went into measuring everything down to the 1/4 round molding. The plan was solid and he was able to transfer them to "BluePrint" paper. for a very reasonable fee No one ever sealed th drawings. and the job got done with only one problem. the helper I used for the electrical work was no up to date on electric code. So I hired a licensed electrician to get the Electric Approved. By that time I was over it for getting the job done and that was going to be faster than confronting the inspector with the work that was done, and how I didn't need a licensed electrician if I was doing it myself.

In NJ it does not take an engineer's seal to get a permit and the necessary inspections. But piss of the building department and you can't get anything done without a lawyer. ...and that costs too much

pecmsg

EdTheHeaterMan said:

But piss of the building department and you can't get anything done without a lawyer. ...and that costs too much

Sound Advice

realliveplumber

So each state legislatively adopts their model building code, and the rules to go with it.

In New Jersey, the owner of a single family home may submit plans and obtain electrical, hvac, and plumbing permits if they are doing their own work. The caveat is that you must reside in the building. The idea is that you have a right, and if you mess up you are only hurting yourself and your family.

Townhomes, condos, etc. are not included in that law.

it looks like in Minnesota a homeowner can do their own electrical work, but I didn't see anything about plumbing and hvac.

You should call the State, they will give you the answer.

EBEBRATT-Ed

All states are different. MA used to allow homeowner permits for electrical...no more. Gas and plumbing are not allowed to be done by homeowners. (everyone does it just don't get caught). That being said if you need permits for an addition your out of luck doing the work yourself.

Daveinscranton

There are a few monarchs left in society.  Not many.  Where I live, the person in charge of permitting driveways is in a position of power.  No driveway permit = you will not build.  And… it is a question of “public safety “.   Not easy to surmount if you piss that person off.

Next up?  Sewage Enforcement Officer.  (SEO) Without your permit for a septic system, you will not build.  And… it falls into the domain of public safety and health.  I don’t know what court you would bring that case in. If denied.  I have doubts any appeals court would hear the case. The SEO wields extreme power.

After that?  Zoning board/town council.  Local politics at its finest.  Then you get to submit your plans.  And you will play by the rules.  

If you need stamped and acceptable drawings, then you may just need them.  Cheaper than fighting the battle.  Faster too.  I ended up with 23 separate permits and inspections.  Overall, it was pretty cordial.  

If you gain the confidence of the applicable authorities, life will be easier.  

EBEBRATT-Ed

Around here if you don't have city water and need a well the well must be installed and working before the house is built.

Reason is someone built a new house and started drilling for water and never got water.

gotgas

I recently needed a set of stamped MEP drawings and I went on Upwork to get them. Found an engineer who was licensed in the state we were working and told him what we wanted to do. He put the plans together and sent them over stamped. I think we only paid about $500 for that.