Discharging to Brick Sewer

[qaztor]

We have a project where we will be connecting (discharging) to an existing 54" brick sewer (old but in relatively good condition). Installing a new Manhole is not an option. has anyone tapped into a brick sewer? any tips?? thanks

 

[dicksewerrat]

Don't try it unless you have done this alot. Why isn't a manhole an option? When I was in charge of an 800 mile system and part was brick, NOBODY connected to a brick sewer without a manhole. Brick sewers have a tendency to look wonderful. Until someone touches it. then it unravels like a zipper. The risk is too high for you to try this.

 

[Maury]

I agree with Dick. Even if a brick sewer seems in good condition, it's still fragile and can collapse like a house of cards. If constructing a manhole isn't an option, then forget about making the connection.

 

[LHA]

I third the motion. Please use a manhole, even though it will be pricey for 54". Your client will spend more time and probably more money repairing the brickwork which always caves in.

I have seen lots of plans with vague notes like "contractor shall tap into existing sewer and repair in kind". Contractors often either submit an RFC (asking to use a manhole) or just won't bid the job.

Build a doghouse manhole around the existing, and you might be able to do the job without interrupting flow...bypass pumping for a 54" sewer main would likely be thousands of USD per day.

 

[qaztor]

Thank you very much for your input. The reason why we cannot buid a MH is due to its size and lack of room at the present site. I have already started a preliminary plan to extend the new line a couple of hundred meters to the nearest existing manhole where some work will have to be done. The pipe will be flatter than what I prefer as a min. slope but it might work for the best.

thanks again

 

[dicksewerrat]

I can't understand why you can't build a manhole? You only need a space 18" wider than the outside dimension of the main. and a 54" brick egg is about 39" inside plus two layers of brick for another 16". You dig down to the spring line of the main. Bore down 4 8" holes to below the main. clean off the brick outside. Place concrete down the post holes and place a footing on these. Set the manhole on these footings. Before you break into the brick sewer, put 2-4 inches og concrete all over the clean brick that is exposed. Let the concrete ooze out side the manhole. then sawcut into the fresg concrete and brick. Break out gently. Once the hole in the brick is large enough, Place more concrete up to the bottom of the hole. Just remenber to have all the wght. of the manhole resting on your foundation and not the brick.

 

[nackra]

Can you install a liner insert in the brick egg sewer such as Insituform or KM-Inliner:

http://www.multiliner.net/Library/Specifications.pdf

then construct MH? Liner can be designed to provide structural "support" to hopefully minimize damage to brick sewer.

Good luck

 

[Scoomer]

I have seen situations where they have built up manholes despite interference from utilities. Usually it involved "cutting" a side of the manhole structure square with the sidewall of the excavation that contained the interfering utility (as opposed to a full round structure)

For example, we had to connect to a 42-inch brick sewer by building a manhole structure. The structure's total circumference interfered with a 24-inch watermain. They poured the bottom slab, brought the structure up with manhole block, and poured the sidewall between the 24-inch water and the 42-inch sewer. I've also seen them build up sidewalls with manhole block as well.

Typically, if you run this stuff by the City prior to installation, they don't have a problem with it as long as the structure is properly mudded both inside and out.