Storm Sewer Drop Inlets

dayexco

i have a question for those who get into storm sewer work. i have a patent pending. here in south dakota, a typical curb inlet is 2'x3' inside 3'x4' outside. there are 2 avenues we can take in putting these in....hiring a cement contractor to pour these in place, or buying precast. both have advantages, disadvantages. my patent pending, and comes with the blessing of the SD DOT, and 4-5 different consulting firms i work with, is having a plastic company extrude 20' lengths of 2x3 and 3 x4 plastic forms, onsite we cut them to height we need, take a sawzall, cut for your pipe openings, stick in your rebar, throw some restraints on forms so they don't blow out or in. you buy zero plywood for forming, the forming stays in place. EVERY engineer i've talked to has zero problems with leaving the plastic form in place. were it the cost of precast, or forming on jobsite, would you go with it? bear in mind, you've got zero strip down, or haul away of cast in place plywood forming.

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someday, i'll be as patient as Nick.

jmic

Day,
Hi ya doing? Sounds like an interesting concept. But not seeing it or fully understanding it I think I'd still go for the precast.

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___"Remember You Never Get A Second Chance To Make A First Impression"______________________
Joe

denick

Day,

We don't do enough to warrant my comment on our use of it. We do a bit of custom concrete form work and I can see the basics of an easier way to do the job.

Have you done a trial?

Do you have the demo video in production?

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Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein

dayexco

at least locally, you pay triple for precast products from what cast in place is, the plus side is they're made, and on your jobsite as you need them, downside is you still have to get a ready mix truck in their to grout up your pipe openings after they're set. cast in place pluses allow for adjustments if necessary, let's say a gas line that can't be moved, etc. what i'm talking about is a plastic extruded form that you cut off to whatever length you need it. cut the openings for pipe, etc. wherever you need them. typically what happens is the concrete contractor you hire will chop up sheets of plywood to form these up, and not be able to reuse the plywood on the next drop inlet. with what i'm talking about, you form them, pour them, leave them...no stripping, no waste of plywood, well, you're wasting the plastic, but i think that would be offset in the cost of having somebody come back and strip the forms. i've got some drawings back at my shop that maybe i'll post online. btw, i've got a few work pics posted at www.photobucket.com you can type dayexco into the search line, has a few pics of what we do

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someday, i'll be as patient as Nick.

PipeGuy

That inlet, at 5' tall, needs about 36 CF of ready-mix. I can buy a comparable precast unit for under $500 if it's one of several being ordered. We seal the annular space around the pipe with brick and mortar.
There's no way I'd want to pour inlets in place and if I was the approving agency no way I'd want anything other than precast.

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Fortunately I keep my feathers numbered for...for just such an emergency. -Foghorn Leghorn

dayexco

here, they will now allow you to just brick the gap up. if the boxes aren't cast in place, they want a 4000 psi concrete collar poured around them sloped back at a 45 degree angle. on an 18" opening, typically about 1/4- 1/3 cu. yard. if you have 3 openings per box, that's another 85.00 not including the labor to place it.

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someday, i'll be as patient as Nick.

Duff

Day,
Enjoyed looking through the jobsite pics. Isaac looks ready to go in a few more years!
Duff

TMatt142

Day...being I worked in MN for so long, I know exactly where you are coming from!! MNDOT has had us putting those 2x3 puppies in for quite some time. As for your idea, I think it's brilliant! In SD do you still have to buy the pre-cast sump (bottom)? In MN all 2x3 CB's have a 2ft sump to catch debris and sand and stuff from winter months. We usually had those as pre-cast and then formed up the rest around whatever inlets,outlets, and build height. In MN as well, they refuse to allow any type of build out of cement bricks. They only allow 6" of grade rings. Man....patent that and market it in the Metro area of MN alone, you could retire and never have to spank the dirt again!!!! A little side note to these wonderful little Catch Basin structures......When I was still a laborer, we had a job in ST.Paul which had probably around 160 of these CB's. My job, along with another laborer was to pull a compressor behind a single axle, equiped with just a coffee can (so small thats all you can shovel with), 5 gal bucket (between your legs) and a lot of the times a 90lbs jack hammer. Go through each CB, clean out the 2ft sumps of dirt water etc and sometimes a ft of concrete from when the paving crew came by and managed to splooge a 1/2 yard or so when they paved the road. Some of the structures were up to 12 ft deep. No ladders would fit, ya just scaled down the walls, trying to watch all the form nails so you didn't get stabbed!!! Just a little horror story I wanted to share...Thanks for bringing back the memories!!!!!! By the way....We got to where we were cleaning 6 a day! 11 hr days. What a pace!!!