Advice on lifting this slab to see if manhole was covered

[DaveHhh1]

Hi all,

I was checking the drain maps on my property and discovered that the foul sewer line runs through the garden v close to an extension I have. I had plans to knock down or add to this extension but thought the sewer line may create challenges with build over etc.

I have two manhole covers down an alley nowhere near the area I would extend to. I check the flow of sewage and waste and it doesn't go to the back of the property according to Thames Waters map rather to the front.

However there is a sewer line running through the garden according to maps and neighbours flow does go to back.

So I wanted to see if I could get an idea of the diameter of the pipe and used the manholes I can see to do that that's all good got it. But then when I was looking at the crazy paving I noticed a questionable perfect couple of rectangular slabs in the paving. I'm immediately thinking there could be drains under here.

I need to look. Because if they are drains that need access they would have to be moved and that may affect any plans to extend. I can't for the life of me pry them up. Any advice? They got to be drains or at least one which would make 3 or 4 manholes in this property alone.

Thanks,

 

[johnny2007]

Only one way to find out...
Lift them up.

 

[23vc]

Wrecking/crow bar (the rigid type not the flat ones that flex)

 

[noseall]

Hi all,

I was checking the drain maps on my property and discovered that the foul sewer line runs through the garden v close to an extension I have. I had plans to knock down or add to this extension but thought the sewer line may create challenges with build over etc.

I have two manhole covers down an alley nowhere near the area I would extend to. I check the flow of sewage and waste and it doesn't go to the back of the property according to Thames Waters map rather to the front.

However there is a sewer line running through the garden according to maps and neighbours flow does go to back.

So I wanted to see if I could get an idea of the diameter of the pipe and used the manholes I can see to do that that's all good got it. But then when I was looking at the crazy paving I noticed a questionable perfect couple of rectangular slabs in the paving. I'm immediately thinking there could be drains under here.

I need to look. Because if they are drains that need access they would have to be moved and that may affect any plans to extend. I can't for the life of me pry them up. Any advice? They got to be drains or at least one which would make 3 or 4 manholes in this property alone.

Thanks,

Slabbing around an IC tends to settle more than the IC, meaning the covering slab would have tell-tale cracking around it. As said, lift them up with a pick or a strong shovel.

 

[DaveHhh1]

Slabbing around an IC tends to settle more than the IC, meaning the covering slab would have tell-tale cracking around it. As said, lift them up with a pick or a strong shovel.

What's an IC sorry? I tried with a wrecking bar it ain't moving. Seems very thick

 

[noseall]

What's an IC sorry? I tried with a wrecking bar it ain't moving. Seems very thick

Inspection Chamber.

 

[DaveHhh1]

Success. Got one up. God knows what's under here how should I proceed?

 

[johnny2007]

Break the mortar, very gently.
Crack the edges with a chisel and lift it up.
It will probably break into smaller pieces.
In fact, there's a bit on the bottom left that has an edge, try starting the lifting from there.

 

[Harry Bloomfield]

Success. Got one up. God knows what's under here how should I proceed?

Masonry drill, in the middle, see if you hit a steel cover?

 

[DaveHhh1]

Break the mortar, very gently.
Crack the edges with a chisel and lift it up.
It will probably break into smaller pieces.
In fact, there's a bit on the bottom left that has an edge, try starting the lifting from there.

Yeah I saw that and wondered what it is it was quite hard. I'll try a different and see. It's definitely covering something

 

[Notch7]

Yeah I saw that and wondered what it is it was quite hard. I'll try a different and see. It's definitely covering something

Watch out for bodies…..

 

[Ivor Windybottom]

I wonder if it's just that Mr Crazy Pave just happened to have two whole ones and a load of shrapnel.

Do your neighbours have chambers in their back gardens? If so then ask to have a look in them, hopefully this would give more of a clue than just wrecking anything rectangular!

 

[DaveHhh1]

Just seems to be some stone... Not sure I can go much farther... I'm not sure how deep this is.

My neighbour has one in their conservatory a lot further back than my extension. But sewage plans indicate there is a drain line in front of extension.

 

[Ivor Windybottom]

It's possible that your neighbour's chamber is just the head end of their own private pipe that goes under their house to the pipe at the front.

The plans are likely to be right!

 

[DaveHhh1]

Yep I think the plans are correct. What I want to ascertain is if there is a IC under here. Because if there is I'm unlikely to get a build over agreement to extend sideways or if I do a huge expense to move the chamber. Anyway I went down a couple of inches and it's solid. No idea.