# Brick Invert/channel w/ brick bench in sewer MH, Any tips never done this before...



## Little (Jul 22, 2006)

I gotta install my sewer in a week and I have to use a special brick and latex coating for the channels and benches in the new manholes. In the specs, it says i can use an 8" pvc pipe cut in half to use as the channel, and i will do this on my straight thru mh's. I have two with bends thought that i will have to do the entire channel with the brick. Any of ya ever done this? Any tips? We are going to do a practice one in the yard on an old mh we have laying around.


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## PipeGuy (Oct 8, 2004)

First-off: Please just go ahead and hire someone who knows how to do this. It couldn't cost you more than several hundred dollars a channel to hire a pro and then if it doesn't look right you just get him to re-do it. If you absolutely can't do that:

You'll need 2 - 3 times the brick and mortar that a real bricklayer would use.
A couple practice runs is a must.
You'll need properly mixed mortar per the specs.
You'll need solid sewer brick per the specs.

Lay the long narrow side of the brick(s) facing the channel except at the top of the channel (the bench) lay the short narrow side toward the channel.
Build "spines" in the channel first - that is the flat surface at the bottommost course (the invert).
Build the first "spine" so it provides a smooth even slope from the invert of the lowest pipe to the invert of the pipe which is most opposite the lowest pipe.
Then build spines from the first spine to the invert of the next highest pipe, etc.
All the bricks in the spine are layed on edge (plumb) with their long narrow sides up (and down for that matter).
The surface of each spine should be smooth and free of protruding joints.
You'll need to fill beneath / alongside each course with brick/mortar (or dry-mix if the specs allow) to allow you to slightly "roll" each subsequent course to match the curviture of the pipe.
By the time you've laid up to the springline of the pipe the courses should have rolled enough that the bricks are now layed flat with their long narrow sides facing the flow.
From the springline to the bench bricks are layed flat and the edge of the channel is held plumb with the pipe's springline - that is the edge of the channel doesn't follow the pipe's curviture in the upper half of the pipe.
The top of the last course of brick (the bench) should be even with the top of the highest pipe at the edge of the channel and slope slightly upward towards the wall of the manhole.
At the bench lay the bricks flat with their the short narrow edge facing the channel.

It goes without saying that you'll have to cut bricks with a brickhammer to fit the curves and slopes presented by the various pipe slopes and angles of entry at the manhole.

I've never applied a coating to sewer brick. Sounds like "painting" to me.


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## Little (Jul 22, 2006)

Thanks alot pipe. I hear ya on just hiring someone to do it, but we will go ahead and do our practice runs and if things seem a little tough or are not working out, then we will go ahead and get someone with experience. 

I am however excited to try something that our company has yet to do. 

Have you ever done any with the PVC pipe used as the channel? I have to check my spec sheet again and see what they say about the bench if using the PVC pipe for the channel, as i'm curious why I wouldn't be able to just pour concrete there as no sewage flow goes there.


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## S.R.E. (Apr 8, 2010)

I have used PVC for the channel before and we used mud to build the benches on the sides. I have also channeled an angled MH using mud. You have to be patient and use the right mud. Can you use precast? Most people around here use precast with pre built channels.


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## Little (Jul 22, 2006)

Nah no precast in this town ha, they are one of towns that stay old school. Well the manholes are precast but they want the brick in the channels.


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## rino1494 (Jan 31, 2006)

Why in the hell would they want to use brick ??

There is one town in my area that still wants clay pipe for all new sewer mains.


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## Little (Jul 22, 2006)

I'm just glad that all the 4" laterals tie into the 8" main and not into the manholes as we can do the pvc channel like i was saying in all the manholes that are straight thru. I only have two manholes with bends, both at the start of the run.


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## Gnella (Jan 16, 2009)

Can you use electrical pvc for the bends? They have a larger radius and will usually work good in some situations.


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## Little (Jul 22, 2006)

Nope they are only allowing the PVC for straight thru manholes.


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## jmacd (Jul 14, 2009)

somebody post a photo of one so we all can see what he has to build.


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## WC&T (Feb 22, 2010)

rino1494 said:


> Why in the hell would they want to use brick ??
> 
> There is one town in my area that still wants clay pipe for all new sewer mains.


 
They still make clay pipe? If i asked my pipe supplier for clay pipe he would probably giggle.


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## Little (Jul 22, 2006)

I checked out bunch of pics of old school sewers and i have a pretty good idea now how its supposed to look. Still haven't gotten around to doing test run as got some other stuff coming up first. I will def take some pics of the install.


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## Dozerman56 (Dec 11, 2009)

Oh yeah, VCP is still used in a number of places. It's far more corrosion resistant than PVC or DIP. And it's been 20 years since I left NH for NC, but last I knew any invert built in NH was going to be water struck brick. Durham NC still wants brick inverts right now, I know from personal experience.


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## dayexco (Mar 4, 2006)

brick inverts sound to me like a bricklayer's union having enough influence to save their jobs.


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## Little (Jul 22, 2006)

Thursday i met with the sewer inspector and he took me too a job down the street and we popped some manholes both straight through and ones with a bend to show me how they are done. REal nice guy, it looks pretty simple. Gonna do my first one wed if weather is ok.


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