Can anyone decipher masonry and drainage requirements

[mark2457]

Hi All

Just got detached garage requirements from village.

Drainage

Any new or rebuilt accessory buildings with a floor area over 400 square feet shall have gutters directed to the front of the lot to drain to the street, a dry well system, or an open and improved public alley with positive drainage. Subject to Engineering Division approval.

It's at back of lot, so can't run gutters to front of lot. Does anyone know what specs are for a dry well? (depth, width, material, covering, etc.)

What the heck is "an open and improved public alley with positive drainage"

General Construction
Slab replacement permitted only if independent of frost depth foundation.

Foundation & Floor
Masonry Construction

• 5" concrete slab on 4" gravel/stone base
• Minimum 12" trench with 20" bell on all four sides. Foundation to extend 4" above grade and a minimum of 42" below grade or formed footing and foundation.
• Minimum 6 bag mix with 5-6% air.

What does "Slab replacement permitted only if independent of frost depth foundation." mean?

Totally perplexed by this: "Minimum 12" trench with 20" bell on all four sides. Foundation to extend 4" above grade and a minimum of 42" below grade or formed footing and foundation."

Frame Construction
Siding 6" above grade, brick to be 4" above grade.

I'm using siding, so does this mean the foundation/floor has to extend 6" above grade?

Walls
Short walls to be braced per current adopted IRC.

no clue what this means


Can anyone interpret for me?

Thanks

Mark

 

[C96]

Hi All Just got detached garage requirements from village.
Drainage


It's at back of lot, so can't run gutters to front of lot. Does anyone know what specs are for a dry well? (depth, width, material, covering, etc.)

Basically most lots when originally graded prior to building the structure were designed and graded for all drainage to be directed towards the street.

So, the new structures gutters & downspouts need to be directed to an area on your property where the natural, or man made run off will eventually take it to the street.

The gutters / downspouts themselves do not need to extend all the way out to the street.

Hi All Just got detached garage requirements from village.

Drainage


What the heck is "an open and improved public alley with positive drainage"

Basically the same as your street out front as far as drainage is concerned.

If such an alley existed behind your property you could direct the run-off towards the alley.

 

[altersaddle]

I'm sure others with more experience in Illinois (and similar jurisdictions) can give better advice, but I know what a few of those terms mean.

I built a 288 square foot workshop behind our house. Tying the gutters into the City storm drain would have torn up our whole property, so instead we installed a rock pit (which I presume is a dry well - as opposed to a wet well).

It's a trench filled with rocks with a drain pipe in it, so that the rain runoff from the roof has somewhere to go temporarily before being absorbed by the ground. Sort of like a septic field, except ONLY for rain water.

We had to get our pit designed and approved by a geotechnical engineer. Even the engineer was pretty surprised by this (it's a hole with rocks in it) but it made the inspector happy. Cost us an extra $800 or so.

I interpret an "open and improved public alley" as a paved access lane behind your property, with either surface runoff (gutters) that let water drain, or with storm drains that connect to the municipal system.

If your region is subject to freezing ground, then it's also going to be at risk of frost heaving. Most of the language around the foundation requirements are to deal with that.

I can't find a proper reference online, but this is close:

http://www.extension.umn.edu/garden/landscaping/implement/images/deck_footings_fig_8.gif

Notice the (bell!) shape of the concrete below the post. That shape will stop it from moving when the ground freezes and moisture in the dirt expands. You need that on your workshop so it doesn't destroy itself come winter.

Dunno about the rest. IRC could be International Residential Code though.

 

[Firebird 1]

The drywell depends on the township requirements. I have seen small holding tanks with perforations maybe 100 gal or so that act as drywells. At my last house the county made me put in a drywell for my rain gutters to run to. It was 12' x 16' x 12' deep lined with geo tech fabric, and filled with #2 stone. That system was well into the thousands of dollars.

 

[csp]

x2 on C96's comments on drainage. Above ground drainage towards the street is acceptable provided it goes to the street and not to a neighboring property.

What does "Slab replacement permitted only if independent of frost depth foundation." mean?

It means that you can remove the slab and replace it if it is a free floating slab not connected to frost footers or the foundation wall (except where it may sit on garage door openings). This would exclude a monothic pour where the slab and footers are all one piece of concrete.

Totally perplexed by this: "Minimum 12" trench with 20" bell on all four sides. Foundation to extend 4" above grade and a minimum of 42" below grade or formed footing and foundation."

If you're doing a monolithic pour slab the trench has to be at least 12" wide and flare to 20" at the bottom. The top of it has to be 4" above final grade and the bottom must be 42" below final grade. The other option is formed concrete footers and stem walls that also have to be 4" above grade and extend 42" below.

I'm using siding, so does this mean the foundation/floor has to extend 6" above grade?

It means that the bottom of the siding must be at least 6" above grade. Generally the siding extends all the way to the foundation, so by default the foundation would also be 6" above grade.

 

[readhead]

Go to the building department and ask. Most of the time they will be helpful.

 

[mark2457]

Thanks for info guys

 

[jimbbski]

I grew up in Chicago so I know it's a pain in the *** to build anything there. I hope you are on a first name basis with your alderman as he can "open doors" and "cut red tape" for you. Of course it helps if you make a contribution to his re-election campaign fund!

 

[mark2457]

I grew up in Chicago so I know it's a pain in the *** to build anything there. I hope you are on a first name basis with your alderman as he can "open doors" and "cut red tape" for you. Of course it helps if you make a contribution to his re-election campaign fund!

I'm actually buying in Skokie. Do they have Aldermen in burbs? (I'm an expat)

 

[kbs2244]

Skokie is different.
But it is the same.
Find something like what you want to do.
Find an inspector and talk to him about what you want to do over coffee (or even lunch)
"I want to do what they did over at ..... What do I need"
Do not be suprised if he pushes you at a local contractor.

 

[theoldwizard1]

Frame Construction
Siding 6" above grade, brick to be 4" above grade.

I'm using siding, so does this mean the foundation/floor has to extend 6" above grade?

Think of it as a 4" curb that goes around the perimeter, expect of course where the garage door is, assuming the garage floor is "at grade". It can be brick or block (likely filled with concrete) or possibly poured/cast with with the foundation.

Totally perplexed by this:

Minimum 12" trench with 20" bell on all four sides. Foundation to extend 4" above grade and a minimum of 42" below grade or formed footing and foundation.

and there is your 4" curb !

I don't know how you dig a trench that is 12" at the top and 20" wide at the bottom. I suspect it will just be 20" wide all the way down.

This is what it would look like

but the only way I can think of doing it is in 2 pours. The first 20" wide to what ever thickness (6"-12"?) and then forms on top for a 12" wall.