Porch foundation digging and unexpected pipes found

[markblue777]

Hi all,
So I broke ground this evening on the porch foundations and have found a couple of plastic pipes higher up than I was thinking.

So some context, just at the top of the picture is the soil inspection chamber.

so I am expecting a pipe say a meter down as that is about the bottom of the inspection chamber.

now say at around 20cm down the grey pipe is there (next to that in the pic on the right is what appears to be some silicon, may be wrong with that but it seems to be the case) and then 20 cm down from that is the brown pipe (the direction the brown pipe is running seems to go past the inspection chamber)

over that side of the house (where the grey pipe appears to be going) is the gas and elec meters so i am wondering if that is covering the gas or elec line. Under the grey pipe is polystyrene. Around the brown pipe is pea shingle from what I can tell compared to the ground around it.

Just wondering if anyone has a rough idea on what they could / would be.

if you need more info or pics let me know

Cheers
Mark

 

[oakfield]

The brown pipe is a 4" drainage pipe, so could be a soil pipe, rainwater, soakaway etc. are there slots on the bottom of the pipe? If so, it is a soakaway pipe.
the grey pipe looks like ducting, could be for electric, telephone etc, there should really be a warning tape in the trench above gas or electric and both should be at a minimum depth.

Are th

 

[markblue777]

Hi Oakfield,

I'm imagining your have some more to write as it cut off haha.

anyway I will have to dig under the brown pipe some more to see if there are slots but I am thinking it is for some type of drainage and not soil as the direction it runs is away from the main sewer entry point (from the houses) and in the other direction is just a field that sits above a motorway tunnel so

I am sort of thinking it could be a soak away but as i said i will dig more and have a look under it.

Cheers
Mark

 

[blackrodd]

Sorry to see the dreaded pipe work, Here's a quick read for you to see what's involved in bridging the services.
Personally, I would go to plan "B", re instate what you have just removed and build something lighter on the base.

http://www.diyfixit.co.uk/building/foun ... n-run.html

Regards Rodders

 

[markblue777]

Hi Rodders,
How do you mean plan "B" do you mean re-fill the hole and lay a concrete slab (say 150mm thick) on top and build on that?

Cheers
Mark

 

[blackrodd]

Yep! loads of work involved for a small porch, Build in timber stud and fix a membrane and expanded metal lath (EML)
on the outside and plaster, follow the roof line above but lower, as the planners like to see, on a later addition to the property.
Regards Rodders

 

[markblue777]

Hi Rod,
Yeah it does seem like it would be a hell of a lot of work for the size the porch will be as it is just timber framed (prob 2 course of brick at bottom more for a look than anything else), so really should not weigh all that much. I was going to clad it with softwood so would that still be ok to do instead of the metal lath (I imagine the plaster would prob weigh around the same amount as the cladding anyway, like not much in it)

The porch falls under permitted dev and no building regs as well but obviously want to make sure it is safe and to not negatively effect the value of the house.

Cheers
Mark

 

[blackrodd]

Yep, you're allowed 2 mtrs square outside dimensions, but they will usually insist on keeping a "step" in from a vertical line of 100mm and a lower roof line to denote a later addition in a buildings history, and also I would think any sewer/foul water bridging will bring the whole project into building regs.
Suggest you don't do any digging, build a shutter the base size, and put some chippings on the pipes, as there should be, sand polythene and the conc base.
Regards Rodders

 

[markblue777]

Just another note with regards to the slab.

with a quick look online I think I will go for either
a slab-on-grade foundation or even Frost Protected slab-on-grade.

http://www.concretenetwork.com/concrete/foundations.htm

any recommendations?

from what i have seen from digging I done our soil is clay and ballast leaning more to sand and ballast from what I saw

Cheers
Mark

 

[markblue777]

hey Rodders
When you say chippings on pipes do you mean to put pea shingle around the pipes and then back fill with the soil.

and then in the form put hardcore (compacted), sand (compacted), polythene (insulation)?, DPM and then concreate?

Cheers
Mark

 

[blackrodd]

If you have the depth of room then either would suffice, But what does you're local council recommend in the way of frost protection?
In the main, these building inspectors do know what they are talking about and make good sense, I've found here in Sunny Devon.
Or ask a good local builder.
Regards Rodders

 

[markblue777]

ok i will give the council a ring tomorrow and see what they say about frost protection.

Thanks for the help

Will update what I do and start a WIP thread

Mark