Curb Drainage is better with Curb Nozzle!
A durable curb drainage solution is finally available.
Questions about Curb Nozzle?: Call or text 713-884-6141 or email gbeck 'at' texasengineer 'dot' com.
When ready to buy, tell us how many Curb Nozzles you need with your shipping address and email. We'll email a quote with shipping (~$9 to $12 in USA) and any sales tax. You can pay online and your Curb Nozzle(s) will arrive in 2 to 3 days via UPS or Fedex.
What is a Curb Nozzle?
Curb Nozzle is our Patent Applied nominal 2" tall x 6" wide PVC nozzle end that replaces the last 12" of 4" diameter PVC pipe. It fixes the curb breakage caused by forcing a 4" PVC pipe though a 5" to 6" tall concrete curb (see photos).
How does it work?
Simply connect your 4" PVC drainage pipe and align the Curb Nozzle bottom with bottom of your curb. Curb Nozzle increases the concrete cover by 250%+ while providing the same storm water flow and velocity.
What else is needed?
A standard 4" PVC drainage coupling, or a 4" internal PE drainage coupling. We can add 4" PVC drainage couplings for $3 each.
Do you make the Curb Nozzle only in blue SDR-35 PVC?
No, but we do think SDR-35 is best for this application. We also make 4" Curb Nozzles in SCH-40 PVC. They sell for $45 each.
How do I know if I need a Curb Nozzle?
If your curb looks like below and you don't like it, Curb Nozzle is a great repair choice. If you're building a new house, tell your builder you want Curb Nozzles to help avoid similar future curb failures.
Should I choose blue SDR-35 PVC or white SCH-40 PVC?
Both are tough but SDR-35 PVC is more flexible and therefore less fragile. Without a Curb Nozzle, both types will be damaged if rolled over when unprotected, but the SDR-35 survives the impact a little better than SCH-40 PVC.
What makes the Curb Nozzle better than a 4" pipe?
This will get complicated! (Not really)
A 4" SCH-40 PVC pipe is 4.5" tall and a 4" SDR-35 PVC is 4.25" tall. A standard curb front is 5.75" to 6" tall (but may be shorter or taller depending on overlays and drainage slopes).
A 4.5" tall pipe typically allows only 1.25" to 1.5" of concrete cover. It may be even less such as 3/4". There is no room for rebar. A 1.5" un-reinforced concrete overlay section easily breaks in shear failure from 1 wheel of a small truck, or a rolling strike from a delivery vehicle.
Curb Nozzle allows for a 250%+ increase of concrete depth, increasing the strength by 2.5 times or more. Each Curb Nozzle comes with two removable rebar holders, so rebar could by added above the nozzle, greatly increasing the overlay strength.
Why can't I just use a 3" pipe?
With 3" pipe through a curb you can add 1" extra of concrete - but there is still not enough room for protect and hold rebar. (Curb Nozzle allows 3.5"+ of concrete to protect and cover the rebar.)
What if I use two 3" pipes. Is that okay?
Yes, but 4" to 3" transition will hold about a 1/2" of water - perfect for growing mosquitoes! You will need a 4 x 4 Wye Splitter, 2 offset 4"x3" reducers, and couplings. This gets you 1" extra of concrete, still not enough room for rebar. (Here's my 3" PVC pipe with the curb cracks already starting - soon to be replaced by a Curb Nozzle)
Curb Nozzle is simpler. One coupling with ~3.5"+ of concrete overlay with plenty of room to add rebar.
I'm a homeowner - how do I install a Curb Nozzle?
Here it is in 3 😉 easy steps...
(1) Confirm your drainage pipe size is 4" and if it is white or blue.
(2) Decide exactly how handy are you with the 'magic mud' of concrete. (2a) If not handy, hire a handy man who is and who either owns or can rent the right tools. (2b) If handy, drag out your concrete tools and clean out or cut out your curb's broken area until you have a clean 8" to 10" wide flat area (12" wide is even better). (2c) Remove broken concrete or cut out any concrete to fit a Curb Nozzle's basic 12" total length back to your existing pipe end. (2d) Cleanly trim your pipe end to fit a coupling between the pipe end and the Curb Nozzle. (2e) Somewhere in here you will need to buy one or two Curb Nozzles. (2f) Decide if you want to add new #4 or #5 rebar or reuse the existing #3 or #4 rebar. (2g) Decide if you want to use an internal or external coupling. Internal couplings are more forgiving, are required for white SCH-40 PVC pipe, but cost a little more. (2h) Drive back to Home Depot or Lowe's or your local Hardware store for whatever you forgot.
(3) Buy high strength patching concrete bag mix and have fun.
That's it in 3 easy steps! If building a new home, specify and require Curb Nozzles so you can avoid all the above fun in the future.