Deck footing depth and framing loads in Berrien County, MI
The numbers a Berrien County, MI deck permit turns on, and the one question worth asking before you draw it. Same figures the free deck span calculator sizes from.
- Frost depth
- 42″
- Ground snow load
- 50 psf
- Code in force
- 2015 Michigan Residential Code (the 2021 edition is enjoined)
- Stairs and guards
- Riser ≤ 8¼", tread ≥ 9"
MRC R403.1.4 (Michigan rewrite) — "shall extend 42 inches below actual grade"
Every member here is sized at 60 psf — 50 psf snow plus 10 psf dead.
Guard required over 30″ above grade, 36″ minimum height. Mich. Admin. Code R 408.30519 — MRC R311.7.4.1 / R311.7.4.2
Why Berrien County, MI sits outside the published tables
The DCA-6 deck tables everybody works from are built on 40 psf live load and 10 psf dead, and item 9 of the guide's own scope says it does not apply to decks seeing snow loads over 40 psf. Berrien County, MI’s ground snow is 50 psf. So a deck here is past the end of the tables, and the deck section of the code in force does not spell out which load controls.
The calculator takes the conservative reading and sizes every member at 60 psf. That is a choice, not a code citation, and it is the reason the question below is worth a phone call before you draw the next one.
Who to ask
- There is no Berrien County building department — Michigan has no unincorporated land, so the township, city or village is the permit authority. Weesaw Township and the Village of Galien are run by the State.
- CONFLICT, do not price around it without a phone call: a freestanding deck MAY be released from the frost line by R403.1.4.1 Exception 3, but R403.1.4 separately states a flat 42" for ALL exterior footings and says footings shall ALSO conform to R403.1.4.1. The text does not reconcile the two. Some townships read it as a full exemption; that is one department’s interpretation, not code. Assume 42" and confirm with the township, city or village before quoting.
- A Michigan Residential Builder license is required and Michigan holds NO reciprocity with Indiana.
- Berrien ground snow load is 50 psf (Michigan Table R301.2(5)). This plan sizes every Berrien joist, beam, ledger fastener, footing and footing product for 50 psf ground snow + 10 psf dead = 60 psf. That is above the 40 psf basis of the prescriptive deck tables (2015 MRC Tables R507.2, R507.5 and R507.6; DCA-6 item 9 does not apply to decks with snow loads over 40 psf) — confirm the 60 psf basis with the township, city or village building official.
- The stair values were confirmed against a rule version marked effective until 2025-08-29; re-confirm if the injunction is lifted.
The question, word for word
Read this one down the phone. It is answerable in a sentence, which is why it gets answered.
“For an ordinary open deck with no roof over it, do you want the framing sized for the 40 psf live load the span tables are built on, or for the 50 psf ground snow load plus dead load? And does that change for a deck with a roof or a screen room over it?”
Size a Berrien County, MI deck
The free calculator carries all of the above. Pick Berrien County, MI in the jurisdiction box and it sizes joists, beams, posts and footings at 60 psf, digs to 42″, and tells you where a number runs past the end of a table instead of printing one anyway.
Open the deck span calculatorNone of this is an engineered design, and none of it replaces your plans examiner. It is the published code, the published tables, and a note where the two do not meet.