Fitting waste for a new sink outlet

[SparrowHawk99]

Hi again, this is similar to my other question just posted.

View media item 68959
I need to channel out a drainage run for the new sink that shows on the floor plan I've added here for you all to see.

Now at the moment the floor is uneven, so I was wondering, should I add the self leveling compound before I dig the floor or after?

I will be adding an inspection chamber to join up the SVP and new sink waste near to where the door is along that dotted line so hiring a CAT scanner tomorrow to make sure I won't hit the incoming mains supply.

I am going to buy a double sealed interior manhole but not sure what to buy, something like this I was looking at http://www.wickes.co.uk/invt/432028, with the manhole cover fitted on top. Is this correct??

I have a friend I'm waiting to hear from but he's not available until Saturday so hoping you guys can drop me some gold

 

[Hugh Jaleak]

Chamber in the link is fine for inverts up to 600mm deep, if the existing drain is deeper you'll need the bigger (450mm dia) chamber. Will need a sealed cover on top as it's internal. Personally I would set the cover at proposed finished floor level, make good the excavation in the floor, then use the levelling compound to bring the lot to a smooth finish.

 

[SparrowHawk99]

Thank you very much Hugh much appreciated.

My drain is no more than 300mm deeper than current FFL so I may be lucky here.

Will I need to bed the chamber ?

Will I need to bed the waste for the sink ?

What size depth/width should I chase the channel ?

 

[Hugh Jaleak]

300 should be fine for mini chamber, depending on floor covering, you may be able to get a cover same size as chamber that will seal for internal use. If under a carpet or lino remember where it is! (If tiling then will probably need to use inset cover.) Bed chamber on some concrete and haunch round to hold in it position.

I'd lay a 110mm branch drain at chamber invert depth across to sink position, 90 bend to bring it to FFL, bed in peagravel before backfilling. Then couple sink waste into that with appropriate connector. (You don't want a run of 40/50mm waste under the floor that'll be extremely difficult to clean out, especially indoors!

 

[SparrowHawk99]

Was planning on laminated timber flooring, will I need recessed or can I use the cover that comes with ? http://www.wickes.co.uk/invt/435230 or perhaps http://www.wickes.co.uk/invt/435227/?source=123_75

I will puncture DPM around the drain and in the channel if it is to be 110mm. Is this still ok?

 

[Hugh Jaleak]

Will need a screwed down, double sealed cover for internal use. (Ensures air and water tightness), such as: http://www.wickes.co.uk/invt/240731 DPM needs to be cut around drains and brought up around the pipe to ensure area is sealed from damp.

 

[SparrowHawk99]

Thanks Hugh.

So only the double seal cover is necessary, or both?

DPM will be punctured, how can I break out without splitting the DPM at some stage? Do you mean new DPM fitted and lapped around drain... this will not be water tight by a long shot??