Residential footing - crawl space

[JStructsteel]

Owner is doing block wall on concrete footing. Building department wants 32" frost depth inside and outside crawl space. Owner just wants it on the outside, said he will dig it out on the inside. Owner wanted 3'-0" clear on inside, so footing wall was 8 courses

He wants me to change the drawings to show this. I was not going to do that. I was going to keep the 32" frost depth shown on inside, and if he digs it out, his risk.

Do you folks agree?

 

[YoungGunner]

I'm surprised the building department would require that - I've never seen frost depth required on the inside. Every home we build here, where we typically have 30" frost depths minimum, digs out the crawl space. I couldn't say for certain that your situation is the same and is warranted to go against the building department. If that's what they require, they are either misinformed or have good reason. Either way, you risk your stamp if you go against it.

 

[phamENG]

It all depends on where the insulation is. If you run exterior insulation down the outside of the foundation wall to bottom of footing and condition the crawl space, this would be doable. But if there's no conditioning, the crawl is cut off from the interior by insulation, and the crawl is vented to outside and can freeze (even if vents close in the winter, the temperature can still drop), the interior footings need to go to frost depth, too.

Your drawings should reflect the requirements of the building code and your engineering judgement. You're not a draftsman for hire. The owner does not get to dictate the detailed content of your designs and drawings just because he/she doesn't like what they are required to do.

Option 1: leave drawings as is and tell him not to do it. This is probably the easiest. But I would say don't give him any of that "at your own risk" stuff. Tell him no.

Option 2: Drop the footings an additional 32" to maintain frost depth even with the crawl dug out.

Keep drainage in mind. Not sure how things are where you are, but around here this would be (and, as I've witnessed a few times, IS) a nightmare for maintenance. I like FEMA's guidance for this: crawl space should be a minimum of 1" ABOVE the lowest adjacent, exterior grade. Combined with a good vapor barrier and good grading, that keeps standing water from sitting in the crawl and rotting everything out.

 

[JStructsteel]

I actually spoke to the building department about this. He sent an email saying it needs to be inside and out. Plus, now that the distance from the joists to the grade is technically less than 18", joists need to be pressure treated.

Im going to leave with 32" inside and out, and let the owner deal with the building department. I will indicate the code requirements, let them decide how to build it.

Reason 1001 residential is a pain. I even sent prelim drawings twice to make sure its what they wanted.

I should send a change order, but I just want this guy out of my life.

 

[phamENG]

Yeah, I only work with architects in residential now. I won't work with homeowners. I rarely work with contractors anymore either. They just want piecemeal it with a sketch here and a sketch there, all the while I'm becoming liable for the whole building and only get to charge 8 hours worth for it. No thanks.

 

[jerseyshore]

I've never had a building department comment on frost depth of a crawlspace footing and around here 90% of the houses have crawls. Lots of interior footings aren't even buried at all, bottom of footing sits right on grade. I think they should, but not required here.

 

[JStructsteel]

PhamENG, anytime I do it direct for a homeowner or contractor (that I dont work with regularly) I require a deposit. I also only work lump sum. Sometimes can be a PITA, but if they pay. This guy is becoming a PITA.

 

[XR250]

Most houses around here do sealed crawlspaces nowadays so the inside is pseudo-conditioned and the interior of the walls are insulated. Is that not a thing where you practice? Would that satisfy the building dept?

 

[JStructsteel]

There is no requirement for a sealed crawl space.

The owner has confirmed with the building department that the interior grade does not need to be at frost depth.

I talked to the county building department. This falls under a city department, they dont have the same requirements.