existing horizontal pipe is 140mm OD clay pipe so I assume 4" internal?
I also need to add a branch to a slot drain from a new slate patio.
I was thinking this:
or this:
I'm not sure i'll have enough fall for proposal 1 hence proposal 2. I will fit the piece of slate on top on the slot drain sump with a sand only bed so that it can be removed for cleaning.
I also need to replace a bottle gully on the other side of the new patio:
with a similar setup but with a standard bottle gully.
For anyone doing similar. I thought I'd post what I did.
Second gully replaced with this
First gully replaced as per my option 2
Patio going in. Every piece of slate is a different thickness and size. I used a bridge tile cutter which I certainly couldn't have done the job without. Cutter was a Rubi Dc 250 850. Amazing tool.
Slate purchased from Berwyn Quarry in Wales as offcuts.
Pointing was done using gthk VDW800 2 part resin mortar colour Basalt. Great stuff and highly recommended.
I forgot to mention, I used 2 x 25KG tubs of Pointing mortar and only just had enough. Patio is almost exactly 20m2. I am not going to work out the average size of slab. Joints are 12mm.
I also treated the slate with VDW950 prior to Pointing. I used about 1 litre for the 20m2
The slate is a mixture of finishes.
Polished/honed, sawn and riven. I tried to get an even spread of finishes but had to work with what I got from the Quarry.
The Quarry supply pallets of offcuts which are approx 10m2 per pallet which I found to ring true. I order 3 pallets and discarded a few pieces that I thought were a bit too thin for my application (approx 20mm). All the pieces I used were between 25mm and 45mm thick. I still have a bit left which o am going to use on a smaller section of patio elsewhere in the garden.
I've never heard of easy bends but will definitely look at those next time I do underground drainage.
A 100ml 90% bend in a run is not rodable an is susceptible to blockages. A 15 %bend at both ends would of been more preferable. Where your 90% bend is should of been an I C for change of direction. There are those out there who would say : " it is only storm water but i don't subscribe to that school of thought. All drainage, regardless of it's use, should be laid correctly.
I see. The originals were there for 60 years without getting blocked so hopefully I won't have problem. If only you were here when I was still just planning. Thanks though. At least I know for next time.