Back drop pipes

[evanstrev]

Having discussions at work about the use of back drop pipe set ups! Whilst I will always try to lay pipes to the min/max gradients with the use of back drops to overcome large falls, another lad who hates back drops tells us to just lay long runs of pipe from A to B irrespective of gradient! Who's right and according to building regs, what is the correct way to overcome large gradients?

 

[Brendan]

Having discussions at work about the use of back drop pipe set ups! Whilst I will always try to lay pipes to the min/max gradients with the use of back drops to overcome large falls, another lad who hates back drops tells us to just lay long runs of pipe from A to B irrespective of gradient! Who's right and according to building regs, what is the correct way to overcome large gradients?

According to one Anglian water man, they don't want back drops, or at least the guy who was signing it off didnt, which resulted in a huge fall to the inspection chamber

 

[hiluxman]

Recent advice here was if using plastic pipe there's no maximum fall now.

I often suggest back drops for jobs and the number of so called professionals don't even know what a back drop is.

In terms of regs round here both are accepted methods.

 

[Smiffy]

Recent advice here was if using plastic pipe there's no maximum fall now.

I often suggest back drops for jobs and the number of so called professionals don't even know what a back drop is.

In terms of regs round here both are accepted methods.

I think the length of run at maximum fall is limited but don't know to what.
I work with eastern Europeans that will just fit a short run at 45 degrees instead of a back drop. I would rather the back drop as future maintenance is easier.
And often with staged drainage you have no choice. We often install footings and internal drainage before inverts of the whole system have been finalised. So better to install everything as high as possible and stick a back drop in than to install to low.

 

[hiluxman]

I think the length of run at maximum fall is limited but don't know to what.
I work with eastern Europeans that will just fit a short run at 45 degrees instead of a back drop. I would rather the back drop as future maintenance is easier.
And often with staged drainage you have no choice. We often install footings and internal drainage before inverts of the whole system have been finalised. So better to install everything as high as possible and stick a back drop in than to install to low.

No, as I said no maximum here now.

 

[6feetdown]

I would stick with building regs until the time if and when they change them, or get something in writing from the people who tell you otherwise. If something legal ever happens a professional will always try and use regulatory guidance i would think

 

[DaveDCB]

Until the book is updated I’ll keep putting backdrops in when required. I see it from both points but no way am I going back to a job when a book reading inspector won’t sign off my work because I think I know better.
They aren’t difficult just afew more fittings and abit of planning.

 

[JerryRtilt]

Until the book is updated I’ll keep putting backdrops in when required. I see it from both points but no way am I going back to a job when a book reading inspector won’t sign off my work because I think I know better.
They aren’t difficult just afew more fittings and abit of planning.

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Another good reason to use backdrops is it saves digging such a deep trench

 

[DaveDCB]

Another good reason to use backdrops is it saves digging such a deep trench

Definitely on that job as the main pipe run ran along existing house, no backdrop would have put me below existing foundation level! Ie no!

 

[Furniss]

Not often needed but we use short run of 45° not backdrop,

 

[Stroppymonkey]

Who remembers Mascar Bowls? See a few of them around still. Dont drop your van keys/phone in one of them!

 

[Giles]

Always backdrops the only way to do it properly, the science says on too steep a gradient the solids are left behind by the water

Regs says backdrops, unit do it to regs no come back on you. Plus as been said keeps trenches shallower and safer

 

[Furniss]

Always backdrops the only way to do it properly, the science says on too steep a gradient the solids are left behind by the water

Regs says backdrops, unit do it to regs no come back on you. Plus as been said keeps trenches shallower and safer

Backdrops come from a different era of pipe ,they are still best in certain scenarios as discussed, but with modern pipe not always necessary - never had a callback in 20 odd years so it must work.
They dropped the 4% max rule over here a few years ago.

 

[DaveDCB]

The French have smaller poos so it doesn’t really count does it?

 

[Furniss]

The French have smaller poos so it doesn’t really count does it?

Yes and they are more slippery

 

[Lancs Lad]

Yes and they are more slippery

Crap joke

 

[JerryRtilt]

Yes and they are more slippery

The velocity that they arrive at in the chamber also has to be taken into consideration ?

 

[bobthebuilder]

The velocity that they arrive at in the chamber also has to be taken into consideration ?

splatt factor as a building inspector commented

 

[6feetdown]

The French have smaller poos so it doesn’t really count does it?

Looking at the size of a lot of our folk i well believe that

 

[6feetdown]

The French have smaller poos so it doesn’t really count does it?

Looking at the size of a lot of our folk i well believe