Cutting Concrete Slab To Add Drain Line??? Drain for Drip System - Best Option?

[tanglovers]

Hi All,

I am in the process of building out new ray tank - 520 gallon display - 650 gallon system.

Part of this system will be a drip system. I am trying to figure out the best way to run the drain. So far I have come up with 3 options. The closed drain I have is about 15 feet away across a soon to be finished bedroom.

1) Run drain outside like a greywater type system. I live in Michigan though and I see freezing in the line / water backing up being an issue

2) Use a sump pump to pump the water out of a drain reservior and pump it through the ceiling into the drain.

3) Cut a trench in the concrete floor to the drain and repour the slab.

Option 3 is the most work but I think would allow for a gravity drain. If I go this route - any advice?

I can use PEX, PVC or what?

How much drop per foot of run to get the water to drain sufficiently?

How far down from the top of the slab does the line need to be? I will be tiling over the slab when this is done.

Thanks!

 

[Bderick67]

Cutting the concrete will be alot of work. Maybe you could use both options 1 & 2. Have the water drain outside and when frozen use the pump instead.

 

[tanglovers]

The amount of work is not a concern for me to be honest. I prefer to do things right the first time. I would rather not cut the concrete and go that route but open to it if people feel it is the best option.

 

[Inglorious]

I feel that if you go for option #2 then you are just asking for trouble down the road. I've cut a trench for a shower drain that ran about 4' before and although it sucked more than a bit, in the long run it was the best way to go. If you really want to do it properly, and will have this setup for many years to come than the trench is the way to go. As for the drop you'll only need 1-2" over the distance for it to be effective. As for #1 I would abandon the idea. Between living in Oklahoma, Wisconsin, and Iowa I know all to well how easily a sump pump drain can freeze in the middle of winter...don't risk it.

 

[tanglovers]

Thanks, for the info!

Cutting a trench, roughly how deep below the surface of the slab can the line be? PVC or Pex be best?

 

[Michael Day]

If you use option 2 you can get a heat trace product which is used in refigeration for freezer drains, very easy to use and cheap to run and cost wise would be cheaper than option 1 or 3. Also doesn't get too hot so can be used with PVC

 

[tanglovers]

I thought about these or condensate pumps.

I should have added the drainage will likely be 65-100 gallons per day. I was concerend this would be much more then this type of pump would be able to handle long term.

I then figured well I could have a backup float to shut off the source water if the float is tripped then wondered if I am making this more complex then needed just to avoid cutting the concrete.

 

[Inglorious]

I would make the trench 1" bigger on all sides than the drain, so for a 3" pipe you'll cut a 5"x5" trench. I'm not a plumber though so what I did might be overkill. Everything I've learned from plumbing has been passed down from my dad who learned by trial and error. As for the actual plumbing I've only used PVC, with good results, but can't say if pex would be better, maybe someone else can chime in with a better answer.

 

[tanglovers]

I think PVC would likely be the best. I am unsure Pex comes in that big anyhow thinking about it.

 

[rik01]

I'm not a plumber but I do concrete does your slab sit on the ground. if it does then it is probably only 6 inches thick with wire mesh in it then you should have beams that could be anywhere from 12 inches to 18 inches wide, that will run the same direction with any of your support walls. They will be anywhere from 18 to 24 inches thick. If it was me doing the job I would cut the trench atleast a foot wider than the size pipe you decided on and i would do a full depth cut on the concrete and remove it leaving the tops of the beams in tact, I would also use the smallest pipe possible maybe 2 inch or 3 inch schedule 40 pvc. I would also drill dowel pins every eighteen inches on center on both sides of the trench offset from one another to support the weight of the new concrete that way after the concrete cures it doesn't sink lower than the top of your slab if the ground below it moves or shifts any. you really only need 1/4 inch of fall for every 10 feet of drainage pipe of any kind, you can even run it level for the whole length only drop it the last couple of feet. you will need atleast 2 inches of coverage on top of your pipe with concrete so it doesnt crack up under the floor you lay on top of it. you may think its alot of work but I do these kind of jobs about every two or three months for plumbers in commercial settings like malls and public building when they have to move bathrooms and grease lines and plumbing for kitchens. Also if you have a post tension slab I wouldn't cut the slab at all for fear of cutting a tensioning cable.