New extension waste pipe worry

[iain14]

Hi, I am getting an orangery attached to the back of my house and the plan is to knock through the wall to make it open plan with the kitchen. The work has started and all of the brick work has been completed as has the concrete floor. However, the water waste pipe from the kitchen sink has been left in place and the concrete laid over the top of it. This pipe is going to have to be removed as the wall in which it runs down is going to be knocked out. Now, should this pipe have been removed prior to the concrete being laid? As it runs along the side of the house and then out of a hole that has been made in the orangery brick work, is the concrete floor going to be weakened at this area when the wall is knocked down? If this is the correct procedure what is done to the pipe when the wall is knocked down, do they just fill it over with some concrete? I have attached a few pictures to help make this a bit more clearer. The plan was to have the waste pipe in the house and come out where you can see the second one in the first picture. The second picture shows that the concrete is down and on top of the waste pipe.
Thanking you in advance.
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[ree]

There's no problem with leaving the waste pipe in the concrete - cut it off and pack the first few cm's with a dry mix of sand and cement.
At the gulley cut it or pull it out, and brick up.

AAMOI:
Where's the DPC?

The bricklaying is pretty dirty - with splashes and snots.

Why the air bricks? Will the slab be screeded?

Was your slab laid on hardcore and insulation?

I dont see the membrane lapping up the house elevation?

The remaining waste at the gulley can be re-arranged to neatly discharge into the gulley.

Whats happening at the extension jog-out, with the white RWP discharge, and the water coming down off the step & cover flashing on the extension roof abutment? Such details can create potential leakage difficulties down the line.

 

[iain14]

Hi Ree, and many thanks for your post.

The bricklaying doesn't look too grand in the pictures shown, after this was taken they have tidied things up a little.

I was told from the architect, before the work commenced, that the slab is going to be screeded, 125mm insulation with around 75mm screed on top, all laid on top of hardcore.

The DPC? I'm assuming you mean the drain pipe connection? Apologies as I'm a novice at building work. The drain pipe that is still in place was meant to be redirected inside the house to join up with the other waste pipe that is seen in the first picture, so that when the wall is knocked down then no pipes will be seen.

Again as for the membrane lapping up the house elevation, that wall is due to be knocked down to make it open plan with the new build, not sure exactly how much of the brick they will be taking out down at the floor level, again I'm assuming that this is why there is none there.

The extension jog-out, guttering from the new build will join up with the white RWP (Rain Water Pipe?) and the down pipe to the drain, if that makes any sense?? Once it is all finished there will be decking boards laid from the new build to the step that is seen, the ground underneath slopes gently to the drain in the corner in the first picture.

The extension roof abutment, as it's going to be a glass roof I think they use lead flashing.

Once again, thanks for your reply, I hope I have covered all that you have asked. The main problem is that I am not at home to over see any of the work as I work away from home. My main concern was that drain pipe being cemented over and I'm glad to hear that it shouldn't be an issue.

If you have any other suggestions or comments then please let me know.

 

[ree]

Thank you for the reply, i understand how difficult it must be for you. i would have similar difficulties attempting your work.
Perhaps ask your builder about some of the concerns i've raised? Do you have a copy of the approved plans/drawings?

1. But has the slab been laid on hardcore (pic 1. doesn't show hardcore) and insulation? I presume that the white stuff peeping up at the edge of the slab is the edge insulation?
The screed usually comes on top of the slab.

2. Damp Proof Course - i dont see it in the pics on the orangery threshold? Check around the brickwork for a black plastic DPC at that level.

3. The membrane should should be seen to lap up all walls - that is confirmation that its fit for purpose, and hasn't been left short. The membrane should go above the screed height and be cut to suit later.

4. There is a plastic air brick near the gulley - what purpose is it serving? Are there any other air bricks? Does the kitchen have a solid floor or suspended?

5. FWIW: make sure that all roofing, guttering pointing, & sat dish(move it) etc. above the orangery is in good order before the glass roof goes on the orangery.

6. Also make sure that the builder is intending to install cavity trays above the knock-thro. They go where your neighbour's step flashing shows.

 

[iain14]

Hi Ree, and thanks again.

I have spoken to my wife tonight and she assures me that there was double thickness insulation laid before the concrete slab, said it looked like polystyrene.

I have attached some more pictures that I hope show the DPC at the threshold. Also you will see a white plastic pipe running diagonally along to the house, I'm guessing that this is to supply air to the kitchen floor from the plastic air bricks shown. The kitchen floor is a suspended floor.

I'm not sure if there are any more air bricks down the other side as it runs very close to the small garden wall.

The sat dish is to be moved and the roof was checked and found to be in good condition. When they do the knock through there will be a building surveyor coming round to watch over what and how they do it, also it will be closely inspected after by the surveyor. I know a lot of planning and work went into this knock through as I have asked them to get it open as much as possible. Two large steel plinths (I-beams) have been delivered ready for that job.

Unfortunately the builder has now finished his part and away on holiday, the next team due to come in on Wednesday to start the frame work and do the windows, doors and roof. But he has assured me that by getting building regulations for the job, I get better cavity wall insulation and sub-floor insulation, apparently all doubled up.

We do have very basic plans, mainly just of the finished article, no details as to the floor etc. I questioned quite a lot about the floor as I am putting down underfloor heating so I needed it to be right to suit the system I'm using.

Once again, thank you for all your advice thus far.

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[ree]

You dont appear to have a DPC in either the brick or the block skins.

The vent pipes should have been in four 110mm soil pipes. You have two 70mm or 80mm RWP's.

How will you carry out maintenance on the wall tight to the neighbour's wall, or on what will be a glazed roof slope? Has BCO approved this design?

Cavity trays follow the roof line - they dont sit on the knock-thro lintels.

Bldg. Regs double nothing up - they ask for the bare minimum.

Why you have no plans for, what is in effect, an extension is a mystery?