Vijay Posted April 21, 2017 Share Posted April 21, 2017 I think I've sorted a drainage plan but before I run it past the BCO, could I have any thoughts on it. The blue dots are all the points where they rise through the floors and the yellow lines are the pipe runs. There are already 2 manholes (large red dots) where the pipes are already run and connected into the mains sewage. I have 2 inspection chambers (yellow dots) which then run onto the 2 manholes. I could run IC1 to either manhole (pipe 1 or 2), would it make a difference? Link to comment Share on other sites More sharing options...
Barney12 Posted April 21, 2017 Share Posted April 21, 2017 I am FAR from an expert but I dont think this works: Chambers have an "inlet" and an "outlet" at the lower level. These are fed by 2 or 4 inlets at a higher level. You seem to have runs crossing. Do you even need this pipe? Hope that provokes thought. I'm no expert. Link to comment Share on other sites More sharing options...
bassanclan Posted April 21, 2017 Share Posted April 21, 2017 I think inspection chamber 1 should be moved down a bit, so pipe 2 doesn't doesn't cross the line of foundations. Get rid of pipe 1, I assume pipe 2 will get less traffic over it and be easier to get at if you need to in the future. Are you swapping the gf wc basin and loo locations? Link to comment Share on other sites More sharing options...
Vijay Posted April 21, 2017 Author Share Posted April 21, 2017 Hi Barney12, I've only looked at he manholes that were installed (red dots) and I didn't see why they they couldn't have as many as 5 inlets and 1 outlet (pic attached), 1 would run straight through and another 4 from the sides? I would use EITHER pipe 1 or 2, so wouldn't need both Link to comment Share on other sites More sharing options...
Vijay Posted April 21, 2017 Author Share Posted April 21, 2017 4 minutes ago, bassanclan said: I think inspection chamber 1 should be moved down a bit, so pipe 2 doesn't doesn't cross the line of foundations. Get rid of pipe 1, I assume pipe 2 will get less traffic over it and be easier to get at if you need to in the future. Are you swapping the gf wc basin and loo locations? I've confirmed with the BCO that he's happy for pipes to be within foundations as long as they are supported above with a lintel, but I'd happily move that IC a bit to find the best position on site. Yes, pipe 2 would get less traffic but I wondered if it was better so split things up between the 2 manholes as they are joined by 6" pipework. Yep, I didn't see the sense in having the loo on the other side of the drainage and having pipe running around the walls, sow they will be swapped over Link to comment Share on other sites More sharing options...
MikeSharp01 Posted April 21, 2017 Share Posted April 21, 2017 Cripes - its been so long since one had a drawing room! I guess the best thing is to define the rules and then work it out from there. Here is what I have been using as rules, that I can recall. 1. Keep the falls correct as per BR. 2. Do not have underground joins - IE only join flows at access chambers so you can rod through in case of a blockage. 3. Have straight runs to access chambers - max flows to one chamber looks to be about 5 see HERE 4. Do not split flows out - you will end up with, for want of a better word, muck building up on the split and eventually it will block. 5. keep runs under the house to a minimum and always straight. 6. Employ correct practice when passing through slabs / foundations to allow for differential movement, structural integrity and any possible settlement. 7. There are special rules for dwellings with many toilets that ensue you don't create a backup if everybody flushes at once! (usually the minimum size pipe allowed) Think that is everything Link to comment Share on other sites More sharing options...
Vijay Posted April 21, 2017 Author Share Posted April 21, 2017 Mike, I'm common from London, so I don't have a drawing room, there's only front and back rooms to me lol I didn't think about number 2, I'll have to look at the length of drainage pipe. What do you mean with number 4, don't split flows out? Link to comment Share on other sites More sharing options...
oranjeboom Posted April 21, 2017 Share Posted April 21, 2017 12 minutes ago, Vijay said: Mike, I'm common from London, so I don't have a drawing room, there's only front and back rooms to me lol I didn't think about number 2, I'll have to look at the length of drainage pipe. What do you mean with number 4, don't split flows out? Number two's are the most important aspect when it comes to sewerage I would say! No.4 = You are splitting your outflow into two paths at IC1 in this case. This has the potential to reduce flow of water via either route and increase debris settlement at the point of the split. I think that's what @MikeSharp01 is referring to. Link to comment Share on other sites More sharing options...
PeterW Posted April 21, 2017 Share Posted April 21, 2017 Always combine - never split ..!! Unless you have a perfect split with a matched flow then you will end up with blockages if you try to split a drain. Only reason for doing it is on big installations (i.e. Hospitals, hotels) and then it's done using weir tanks which are all specialist design and installation items. Link to comment Share on other sites More sharing options...
Vijay Posted April 21, 2017 Author Share Posted April 21, 2017 I'm not splitting at IC1, it will be EITHER pipe 1 or 2, not both. The reason both are shown is there is an option and wondered which would be best Link to comment Share on other sites More sharing options...
Vijay Posted April 21, 2017 Author Share Posted April 21, 2017 6 minutes ago, oranjeboom said: Number two's are the most important aspect when it comes to sewerage I would say! Especially if you drink Guiness so I've been told!! lol Link to comment Share on other sites More sharing options...
MikeSharp01 Posted April 21, 2017 Share Posted April 21, 2017 2 hours ago, Vijay said: Mike, I'm common from London, so I don't have a drawing room, there's only front and back rooms to me lo Sorry @Vijay its an in joke with me which is the result of something a friend said to me many years ago, suffice it to say they built an extension on their cottage which included a drawing room because it had been a long time since one had had a drawing room. Link to comment Share on other sites More sharing options...
Vijay Posted May 2, 2017 Author Share Posted May 2, 2017 Just to update this post, the BCO is happy with the plan and happy for IC1 to go to either manhole 1 or 2 Link to comment Share on other sites More sharing options...
DNA Posted May 28, 2017 Share Posted May 28, 2017 Hi Vijay & everyone else, Sorry to open this tread up again but reading it and alot of other posts has caused me to have a rethink about my drainage layout. I'm having a block and beam floor and so far had planned for each internal stack to exit out to an inspection chamber through the cavity wall. However, looking at your drawing you have a lot more drainage internal under the floor than I had planned. If I took this approach it could save a lot in terms of chambers / having to stop up exit points etc. Since I started searching though I have now found an even more efficient approach in the attached - blog about Strawberry Tree Lodge (apologies to the owner of this but I did try to post a link to the blog but it wouldn't work). Here you can see that they have lined drainage stacks up internally and then exited one end to an inspection chamber and then at the other to a rodding point (see bottom right) - saving on chambers and external drain runs etc. Any thoughts on this anyone as I like the idea but have to get my head around having the runs under the floor Link to comment Share on other sites More sharing options...
CC45 Posted May 28, 2017 Share Posted May 28, 2017 Most of ours run under floors to exit in the right direction. Link to comment Share on other sites More sharing options...
Onoff Posted May 28, 2017 Share Posted May 28, 2017 Those external rodding points look like a good idea. Link to comment Share on other sites More sharing options...
DNA Posted May 28, 2017 Share Posted May 28, 2017 (edited) Thats what I thought Onoff - saves loads on inspection chambers in paths etc and just cuts down on the number of bends and places where blockages start. It would work really well for me as luckily enough most of my drain runs are straight lines so I can get away with only two external manholes and a few rodding points. Also just less clutter in the paths making it easier for services / surface water gulleys etc. Anyone got any details of how the floor under the beams should be prepared or are we just talking some pea gravel and mortar to pin the rest bends in place? Edited May 28, 2017 by DNA Link to comment Share on other sites More sharing options...
Nickfromwales Posted May 28, 2017 Share Posted May 28, 2017 You'll have to observe standards regarding spacing between supports, as if it were clips on an external horizontal run, and if it were me I'd put an 18"x18" flagstone down and bed the mortar on top of that. You really need to ensure the rest bends stay put and the pipe runs cannot sag even slightly. Changes of direction / junctions should receive the same treatment. BCO should really be involved here TBH . Link to comment Share on other sites More sharing options...
DNA Posted May 28, 2017 Share Posted May 28, 2017 Hi Nick, Will get the BCO up next week and I've dropped the tecnical inspector a note too. However, if its a reasonably acceptable approach then the workmanship issues don't worry me. I'd still bed everything to falls on 10mm gravel and and set the rest bends out on bases / paving slabs etc. I usually like to pin them in with a brick or two as well so that they cant move if rodded etc - might do the same with the pipe as well. Other than that though I was just wondering what else others would do in setting the pipes out and keeping them in place and also how they felt about drainage done this way Link to comment Share on other sites More sharing options...
Triassic Posted May 29, 2017 Share Posted May 29, 2017 I'd not be happy with the poorly jointed riser ring in the photo above, it's not inserted properly, I'd want to get that sorted out as part of the job. Link to comment Share on other sites More sharing options...
Ian Posted May 29, 2017 Share Posted May 29, 2017 14 hours ago, DNA said: Other than that though I was just wondering what else others would do in setting the pipes out and keeping them in place and also how they felt about drainage done this way Just a couple of thoughts: - if if you can make the design work by taking them around the outside of the house why take the risk of running them underneath the floor? Have you worked out whether the saving in materials is worth the extra long term risk of a major problem in the future? - I'm guessing your ground is good and you have standard strip foundations but I know others will be reading this who may have issues such as peat, clay heave, high water table etc and in those kinds of conditions the risks increase. Link to comment Share on other sites More sharing options...
Nickfromwales Posted May 29, 2017 Share Posted May 29, 2017 Underground soil pipe runs, when fitted properly, are extremely reliable TBH. Gone are the issues with minor heave or settlement cracking clay pipes, and then the nightmare of roots filling the pipe at that break, so imo if there's the means to go under and you can keep to straight or relatively straight runs then I'd really not worry about it. I've seen so many adverse runs ( which have been functioning without issue for decades ) to really worry about runs ( installed according to current regs ) to be panicked by running 'under slab'. The above pic with the end of line rodding points is an excellent solution imo, and the real point to make here is about doing the job right rather than where. . 1 Link to comment Share on other sites More sharing options...
Tennentslager Posted May 29, 2017 Share Posted May 29, 2017 @Nickfromwales Check out your likes total Lucifer?? Link to comment Share on other sites More sharing options...
Bitpipe Posted May 29, 2017 Share Posted May 29, 2017 11 minutes ago, Tennentslager said: @Nickfromwales Check out your likes total Lucifer?? Fixed it. Can't lose our resident Captain Flange to the beast, can we... Link to comment Share on other sites More sharing options...
DNA Posted May 30, 2017 Share Posted May 30, 2017 Hi Nick. Thanks for the advice. I'm with you on this as the space under the block and beam floor lets me have very straight pipe runs and I really like the through rodding ability from both ends. I'm not on good ground either Ian with soft spots and high water table so it avoids things like path settlement & surface water drainage cross overs etc. As you say, workmanship and doing it right will be the most important issues. So, i'll be compacting the area under the internal lines, teram and 10mm gravel all through and rest bends / joints / junctions on a slab with mortar to pin them in place. What are your thoughts on pipe exits through cavity walls Nick? The obvious seems to be lintels leaving a fairly big square hole though I cant believe that someone hasn't come up with a better idea yet. What would you use to seal the holes - I can only think of some cement board? Link to comment Share on other sites More sharing options...
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