Originally Posted by agrostis
Cohesion is going to make almost all that water stay together, this work's on the same principal as those gutter's that only have a quarter inch opening in the front of the gutter, it does work. You will have few drop's escape but not enough to worry about. Use pea gravel underneath the catch basin's for leveling and drainage and you will never see water.
If you have to replace a catch basin, dig a big enough hole that you can pull that basin off of the pipe. This is where not using glue is big.
You can use silicon but it's not necessary and i wouldn't do it. Use duct tape to put everything together, but that's all it's for.
When you talk about 4" drain line's, they aren't airtight, if it's not sloppy loose, it's fine, "cohesion" is your friend.
A rubber coupling with clamp's is overkill, not to mention a unnecessary expense. I would use the speedi-drain's, they aren't that expensive. I have used a 4" 90* elbow with a round grate in a pinch.
As long as you have vented (airflow from one end of the drain to the other) your drain's and have at least a 2% fall over 10 feet, your drainage should work. Good luck.
OK glue isnt an absolute need.
Some of the catch basins will be "in line" on the main run so no matter what when it comes to replacing I will still need to handle that, glue or no glue but that is fine.
Now since I already have the pvc "t", caps and 4" square grate, if I glue the cap on the bottom, is that OK as a catch basin or is a 4" pipe and cap to small for a sump area (I can make it as deep as needed)?
The spee-d basins have a 6 inch round sump but its not that deep, dont know if that matters.
I have a basic grate question:
As long as the GPM can be handled by the grate, does it matter if I use a 6 inch square, 4 inch outlet or is a 9 inch square 6 inch outlet grate better?
Is the bigger one easier to grade to? Should I only use the bigger one if the GPM is needed to be that high?
My pitch is easy to get and I am day lighting.
Thanks for all the answers so far.