cwr Posted January 20, 2020 Share Posted January 20, 2020 Folks, can anyone shed some light on whether a BIGT is really needed? Seems simpler to me to just run 110mm straight to an IC. Am I missing something? Link to comment Share on other sites More sharing options...
ProDave Posted January 20, 2020 Share Posted January 20, 2020 For anyone wondering BIGT = Back Inlet Gulley Trap I don't have one. 110mm straight in from the inspection chamber and then appropriate reducer down to 40mm. Link to comment Share on other sites More sharing options...
Temp Posted January 20, 2020 Share Posted January 20, 2020 We don't have any either. We brought 110mm up in the kitchen under the sink area which is on an interior wall. 40mm waste pipes go into that from sink and dishwasher via an adapter. The 110mm runs straight out to an IC in the garden and we could rod back from there (although we have never needed to). Link to comment Share on other sites More sharing options...
HerbJ Posted January 21, 2020 Share Posted January 21, 2020 +1 to this 10 hours ago, Temp said: We don't have any either. We brought 110mm up in the kitchen under the sink area which is on an interior wall. 40mm waste pipes go into that from sink and dishwasher via an adapter. The 110mm runs straight out to an IC in the garden and we could rod back from there (although we have never needed to). Link to comment Share on other sites More sharing options...
PeterW Posted January 21, 2020 Share Posted January 21, 2020 Only place I’ve used external 40mm pipe is where it’s not seen in a very narrow gap behind a house as the final kitchen layout wasn’t known. Simple job to just core drill and connect to the vent stack on the outside. Link to comment Share on other sites More sharing options...
cwr Posted January 21, 2020 Author Share Posted January 21, 2020 I think the original plan was to run the waste through the wall straight into the back inlet of the back inlet gully (so not exposed), but looking at my section and detail views this is in the middle of the slab, which makes BIGT's even less appealing. 110mm to the IC it is. Link to comment Share on other sites More sharing options...
joe90 Posted January 21, 2020 Share Posted January 21, 2020 I did instal one but with the 40mm pipe connected to it just below ground level so no external pipe on the wall. I did it to give me rodding access and also to collect crud from the kitchen sink rather than let it into the treatment plant. Link to comment Share on other sites More sharing options...
cwr Posted January 21, 2020 Author Share Posted January 21, 2020 That's a good point about collecting crud. However, if I put in BIGT's they'll end up like this with pipe through floor slab (110mm shown here, but same effect if 40 or 50mm): 1 Link to comment Share on other sites More sharing options...
cwr Posted January 21, 2020 Author Share Posted January 21, 2020 Direct to IC more like this. By the way, is a rest bend needed if just for sinks and basins, or can an ordinary elbow be used? I know regs say 200mm rad min, but that's shown on the bottom of a stack. Link to comment Share on other sites More sharing options...
Temp Posted January 21, 2020 Share Posted January 21, 2020 Not sure what the BCO will want. We used large radius rest bends. Google just found this which looks like it has a radius in between a standard bend and a rest bend. Seems cheap as well... https://www.speedy-plastics.co.uk/shop/underground-drainage/110mm-underground-drainage/90d-double-socket-swept-bend/ Link to comment Share on other sites More sharing options...
Russell griffiths Posted January 21, 2020 Share Posted January 21, 2020 Why not use a rest bend, they are so cheap it’s not worth trying to use an alternative. Link to comment Share on other sites More sharing options...
Oz07 Posted January 22, 2020 Share Posted January 22, 2020 I think architects always draw like this. Mist be something about negating need for an aav. Link to comment Share on other sites More sharing options...
cwr Posted January 28, 2020 Author Share Posted January 28, 2020 On 21/01/2020 at 20:35, Russell griffiths said: Why not use a rest bend, they are so cheap it’s not worth trying to use an alternative. Good point, will do just that! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now