I am in Costa Rica and have a concrete block garage with 2nd story above. I want to add 3 toilets, 3 showers and 3 sinks. The sinks and showers are on a separate grey water system. These rooms are sort of like a motel room for my guests.

I am planning on raising the floor under the toilet and showers to allow for plumbing so we can route the pipes through the exterior wall to the back of the building. The main sewer line will run horizontal to the end of the building and then drop vertical for about 6 feet and then make a 90 degree turn travel another 15 feet horizontally and then make another 90 degree turn downward for two more feet and then another 90 elbow for a final horizontal run of about 12 feet to the top of my septic tank where the last 90 degree elbow dumps into the top of the tank. I plan to put a vent at the first vertical section.

Should I use 4" from start to finish, or is 3" OK? I'm thinking 4" with 1/8 inch slope because of the elbows. I will use pairs of 45's wherever I can however I am stuck in a couple of spots and must use 90 degree elbows.

I can put Y-clean-outs at two of the locations where there will be a 90 degree elbow and I can put a clean-out plug at he beginning of main horizontal run across the back of the building.

Building codes here are not an issue. You wouldn't believe how must plumbing is done. They don't use vents or traps. I am using both.

Thank you in advance for any advice you can share. I have a toll free number in the US that rings at my home here in Costa Rica if you want to talk. 1-877-410-1944.

Djweller...

I'm off for the night but will work on this tomorrow AM if I can. Otherwise, check periodically as we have a few guys here capable of answering this question just as well as I can.

Thanks...

MARK

Mark, this one is over my little head but I don't like the sound of 90s in such a conjested set up. I do know that raising the floor for the pipes gets tricky fast. A 4" pipe needs 1/8" per running foor and a 3" pipe needs 1/4" per running foot. That could mean a floor must be raised 6-8" depending on the size of the room. I am glad you understand the need for vent stacks and traps so you have some skills on the books.

DJWeller44: It is good to know that even you don't have to do it the "right way" - you still want to do it the right way... :=D

You pretty much have clear idea how to plumb it. Yes, use 4" all the way and use clean outs where ever possible. As Ballengerb1 correctly suggests, don't use 90's in horizontal runs. Use 45's.

DJWeller44: It is good to know that even you don't have to do it the "right way" - you still want to do it the right way..... :=D

You pretty much have clear idea how to plumb it. Yes, use 4" all the way and use clean outs where ever possible. As Ballengerb1 correctly suggests, don't use 90's in horizontal runs. Use 45's.

There are two places where I just don't have room for using two 45s to make a 90. That is the main reason I went to 4" which everyone here thinks is an over kill. Regardless, I am carefully measuring slope to 1/8" per foot for horizontal runs. I already blew it on the 90 that makes the final dump into the top of the septic tank. Now I see that I could have used two 45s there. Hopefully the 4" size will help this mistake.

I have some photos posted here: Picasa Web Albums - Dennis - 2009-01-30 Pl... (http://picasaweb.google.com/djweller44/20090130Plumbing#)

My building is 80 feet long. I am running 4" all the way from one end to the other with a 10" drop in elevation. Does that sound good. The only water going into this drain system is from the 3 or maybe someday 4 toilets. The other waste water routes to a gray water system using 2" pvc. All of my plumbing is external to the wall of the building and exposed to tropical sun for several hours. Do I need to protect these lines from the sun or the heat of the day?

My floors on the 2nd floor are thick reinforced concrete, so the plan is to have an elevated floor under the toilet and shower to accommodate the pipes which will go through the wall at floor level and then make a 90 to connect to the main line across the back of the building. The connection to the main line will be with a Y fitting.

That's my story. Any suggestions will be greatly appreciated and if you are ever in Costa Rica I will treat you to something nice.

There are two places where I just don't have room for using two 45s to make a 90. That is the main reason I went to 4" which everyone here thinks is an over kill. Regardless, I am carefully measuring slope to 1/8" per foot for horizontal runs. I already blew it on the 90 that makes the final dump into the top of the septic tank. Now I see that I could have used two 45s there. Hopefully the 4" size will help this mistake.

I have some photos posted here: Picasa Web Albums - Dennis - 2009-01-30 Pl... (http://picasaweb.google.com/djweller44/20090130Plumbing#)

My building is 80 feet long. I am running 4" all the way from one end to the other with a 10" drop in elevation. Does that sound good. The only water going into this drain system is from the 3 or maybe someday 4 toilets. The other waste water routes to a gray water system using 2" pvc. All of my plumbing is external to the wall of the building and exposed to tropical sun for several hours. Do I need to protect these lines from the sun or the heat of the day?

My floors on the 2nd floor are thick reinforced concrete, so the plan is to have an elevated floor under the toilet and shower to accommodate the pipes which will go through the wall at floor level and then make a 90 to connect to the main line across the back of the building. The connection to the main line will be with a Y fitting.

That's my story. Any suggestions will be greatly appreciated and if you are ever in Costa Rica I will treat you to something nice.

My 90 degree elbows are only at the top and bottom of vertical sections. I don't have any 90 degree elbows where the line is running horizontal.

When this project is done I will have black water, gray water, hot water and cold water all running along the back of the building. The gray water will be in 2" pvc. Does the same slope work for grey water? Can I just hang the gray water line under or over the black water line? Does it matter if it is above or below?

The hot and cold water lines are going to be my next challenge. I am thinking it might be better to bring the cold water up through the floor from below so that it doesn't get hot from the sun. The hot water pipes here are typically 3/8 inch high temp pvc. That is run through the concrete walls. This is awful as the flow is low and the concrete sucks the heat out of the pipe. I will probably use a solar panel with a roof mounted tank that is above the panel so that the recirculation will be by convection. So, I am not too concerned that the hot water pipes will be outside the building in the sun. I am also planning on using high temp 1/2 pvc for my hot water system. Does all of this sound right?

On a completely separate project, I am thinking to run a new hot water pipe under the eaves to my kitchen in the main house. My hot water for the main house is an electric tank on it's side with a solar panel below it. The reason I want to do this is because it takes forever to get hot water into the kitchen and the flow is low because of the 3/8 pvc they use here for hot water.

I don't want to use an electric booster heater at the sink as I have no 220v there and electricity costs more here than in the states. I could use the old hot water line as a return line so that I could circulate the hot water and then I would have instant hot water in my kitchen which would be really nice. Does any of this seem possible or did I spend too much time on submarines when I was a kid?

Dennis