How to Vent Plumbing

hi I'm Tim Carter from ask the Builder calm and I'm in a pretty strange situation right now I'm up in the Attic of a brand new home and just a week ago I finished putting in the plumbing waste and vent system for this home it was really a fun job to do and just over my right shoulder you should be able to see the full-size vent pipe that leaves the roof let me tell you all about a plumbing vent system for a new home okay this is the plumbing vent pipe right where it leaves the roof of this particular home it goes out the roof right on the other side of that top cord of that flat truss and I know you can't see it but trust me it goes through the roof there the reason it's a four inch pipe is because we're in central New Hampshire right now and it gets very very cold here in the wintertime and you need to have a full sized vent pipe so that these vent pipes don't get choked off with ice what actually happens is right here where I'm standing in this attic it could easily get 20 below zero and the moist warm air that's inside this vent pipe can actually start to freeze and choke off on the inside of the pipe notice right here I transition from four inch PVC to three inch PVC and it's going to stay three inch PVC as it travels to bring air into the system and of course that's how these plumbing vent pipes work a lot of people think that a plumbing vent pipe is much like a chimney for a fireplace where you know in a fireplace you have smoke that goes up and out you know to the atmosphere well guess what what these pipes are really for is to let air from the outside into the plumbing system I know that doesn't make sense but here's what happens let right now let's imagine that no one's using the plumbing system and all of a sudden somebody flushes a toilet well all of that water that rushes from the toilet down the drain pipe down below it pushes air out of the system and that air needs to get replaced and the air comes into this and it is it is sucked down this pipe extremely fast you'd be stunned how fast the air goes through this pipe and so these vent pipes supply the much-needed air that your plumbing system needs to stay in equilibrium now you'll notice right here once again remember this is a three inch pipe and it stays three inch the whole way make sure your plumber does that they're going to try to talk you into just using smaller pipes like two inch or inch and a half it's really a mistake but here we've got a three by two inch T and this particular T is here because this two inch vent pipe goes all the way through the trusses down about fifty to sixty feet through the house and about thirty feet from here it branches off to the left to capture the kitchen sink but farther on it goes down and supplies air to the second bathroom in this home as well as the laundry room but if we come back here what happens is this 3-inch pipe continues on over about seven feet and then it makes a 90-degree Bend where it goes down to start to feed air to the lower bathroom let's go down and look at that okay I'm back down on the floor the subfloor I'm kind of glad about that it can be a little dangerous up there balancing on those narrow trusses but that's a shot up there that you rarely get to see most people never get to get up in those trusses and actually see what the plumbing vent pipe systems doing so once again over my right shoulder you should be able to see the three-inch plumbing vent pipe that is now coming down out of the attic and it's going to start feeding air into this system let's take a look at it okay there is that ninety degree Bend up above that I just talked about a few moments ago and of course if you travel that three inch pipe over you can come over here and you can kind of see where it goes up to the roof but look what happens the air comes through that pipe comes across hits that 90 and it starts to come down and here we are this is the master bathroom and once again this is the first place right here where you have water enter the system that is a three by inch and a half Y with a four five degree Bend on it and that is the branch arm that's what we call it right here for the master bathroom vanity okay so remember once if all of a sudden you fill the sink in the vanity of water to the brim and then you pull the stopper this inch and a half pipe is going to fill completely with water from all of that water rushing into the plumbing system that water comes through hits that 45 goes down the Y and starts to enter the 3-inch pipe and it's pushing air out of the way and it's pushing air down towards the septic system with that air needs to be replaced and as the water flows down the pipe air comes down the vent pipe here you know to replace that air so it's very very important that's how it works now what happens is down in the basement and because it's so dark you're not going to be able to see it this particular vent pipe it makes a 45 degree it makes a 90 degree Bend I'm sorry then right below the wall and it heads off at a 45 degree angle and you can actually see I drew it on the floor here for you you can see those lines well that center line right there is the center line of the pipe and it hits the center line of that see that other pencil that's going through the letter a well guess what there is the toilet pipe and there is a three-inch toilet pipe and right here where that letter A is is a three inch by 3 inch Y and that particular pipe goes all the way across under the floor you know over to the foundation wall there so that's a where the vent pipe actually connects to the main drain system is right under the floor right here with a three by three Y okay let me show you a few other vent pipes so maybe it makes some sense and these these are vent pipes that are once again in the master bathroom check this out okay this is the this big black thing right here I'll go around the corner here this is the shower for the master bathroom and this is the vent pipe for the master bath shower and it connects down underneath the floor it's that's an inch a half pipe yeah and there's a two inch by inch and a half tee that's underneath there because the shower drains need to be 2 inch drain pipe so this particular vent pipe you know comes up up up up up up up and there you can see it connects to another vent pipe that if we go over here and then we start to come down this wall this is the vent pipe that's going to be for the master bath whirlpool which is going to be in this space right in here so I know it sounds crazy but you need all of these vent pipes to supply air for each and every fixture and of course what happens is you can see this inch and a half pipe comes up over here it's up in the attic there and now look at this you can see right here where it makes the 90-degree Bend and it goes over over over here and right there look at that it connects to the 3-inch vent pipe that is coming down from the attic so that is exactly how the master bathroom shower and the master bathroom whirlpool get the air needed for their drain pipes is that cool okay I'm here in the kitchen what's over my right shoulder is the outside wall of the house you should be able to see the windows right there and I'm hoping that you can see the vent pipe that's taking care of the kitchen sink let's take a look at it okay this is the drain pipe system and the vent pipe system for the kitchen sink this is the what we call the branch arm for the kitchen sink and the way I piped this that is an inch and a half pipe right there and but this is a inch and a half by inch and a half by two inch T so it's got inch and a half pipe that comes out you know and goes over to the branch line there that's inch and a half pipe that goes up but this is two inch pipe that goes down to the drain line and eventually connects to the septic system down in the basement so whenever your your plumbing a kitchen sink it's really a good idea to put in a two inch ak is what we would call it and so it gives you extra capacity and it makes it harder for that line to get clogged up but that's an inch and a half branch line that's all you need now here's what happens remember when you fill both sinks with water in your kitchen sink and then you pull both Stoppers you completely fill that pipe right there with water and that water rushes over hits the tea and then starts its path way down to the sewer or the septic system well once again it's pushing all types of air ahead of it down this two-inch pipe and that air needs to be replaced well that air comes right here it comes in through this vent pipe that goes up up up up up up up look it's going to get kind of dark here believe me it'll come back and there's the vent pipe that's going to go across the ceiling we'll look at that in a minute let's take a look okay here's the top plate of the wall the outside wall at the kitchen sink and there is the inch and a half vent line and of course it goes up and here it's going to travel all the way across the ceiling right here and it's got a slope to it it's got a slope just like a regular drain line it's sloping at an eighth of an inch of foot and right here I know you can't see it well you'll be able to see it right here there right or right underneath it right there the vent pipes to the left and they're the inch and a half vent for the kitchen sink connects to that two-inch vent pipe that I told you about back at the beginning of the video all right I've kind of turned around here's the two-inch vent pipe it's up in the attic once again and there is the inch and a half pipe that's going over over over to that kitchen sink if you remember there's the windows but let's come back here and see what happens with this two inch vent pipe so here it is it goes through the trusses we're going to follow it across and you'll be able to see right here it kind of makes a couple of bends so what happens here is the first pipe that comes down from that two-inch vent is an inch and a half vent pipe and that inch and a half vent pipe is the vent for both the vanity sink which is right here and it also Lexx and supplies air through another inch and a half bend pipe for the toilet that you can see in the room right here here is the toilet flange on the other side so once again these vent pipes connect down to the pipes down in the basement sorry it's too dark to see that but once again I'm just trying to explain to you about what vent pipes are in the walls that you can't see and notice when you install these you always put the t's upside down because the air is coming down it's like water in other words it's flowing this way and the bend goes this direction so it comes down and goes that way so that's the way you want the tee to be oriented so that it helps the flow of the air okay once again I'm up above this guest bathroom now and let's see what happens with the rest of the vent line so here it kind of jumps down comes across and right here you can see another connection up there and there's a pipe that's coming down very close to us right here well this vent pipe comes down and takes care of the tub and shower in this bathroom but way up there where that vent pipe makes a 90-degree Bend it's going to go collect and supply air to the laundry room in this home so we're almost done with the vent pipes okay I've walked down a hallway so that you can see it from the other angle but there is the vent line that's going to go across and connect to the two-inch vent but here we have it making that bend and it's coming across the ceiling here right here you can see it here it is there it is and I'm rotating around and there it makes a bend to come down this wall and this is going to be the vent pipe for the laundry room you know washing machine drain here in this room the actual piping is going to be outside of the wall because we don't want that trap you know there's always a trap for the washing machine if you put it in the wall here in New Hampshire it will freeze solid in the wintertime so that will get connected after the rooms finished but that's basically exactly what the vent pipes all about and once the insulation and drywall is all in you never get to see them so this is a very rare time for you to see all these pipes and remember these pipes all have fall to them in other words right here this is the lowest part of the vent pipe in the entire system and from this point all the way back over to the roof the vent pipes go uphill so that the water in the condensate in the vent pipes flows back to this point so understand that there is water you know from condensation that collects in these vent pipes it needs to drain because these pipes can never allow to have standing water in them so right here it all that water flows backwards income it's going to be coming down this pipe right here isn't that cool okay wasn't that pretty cool now you know a little bit about plumbing vent pipes you may first wonder Tim how is it that you know so much about plumbing vent pipes well I know I'm the ask the Builder guy but among other things for about the past 32 years I've been a master plumber I always love to do plumbing I did a lot of plumbing work on Oaks almost all my own jobs and I just find it very interesting and very satisfying to do plumbing work so I just wanted to share what a plumbing vent pipe system is how it works because you know once they get hidden behind the walls the average person never gets to see these wonderful pipes and you most of the time don't even realize they exist so you often have as much piping up in the walls and ceiling of your home then you have actually down below the floor so it's a very important part of the plumbing system make sure if you live in a cold climate you have your plumber installed full-size vents either three inch or four inch so you never get you know cut off from air if it gets bitter cold outside I'm Tim Carter for ask the filter comm if you 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Channel: Ask the Builder

Views: 1,214,734

Keywords: diy, home improvement, remodeling tips, building tips, carpentry tips, plumbing tips, home building, tim carter, askthebuilder, how to vent plumbing, plumbing vent pipes, full size vent, full size vent pipe, frost in vent pipe, prevent ice in vent, prevent ice in vent pipe, diy plumbing vent pipes, how to vent pipes

Id: WBU76ZcrGlM

Length: 15min 37sec (937 seconds)

Published: Tue Feb 09 2016