Foundations.

[Jsmithy]

Hi all,

I hope i can get some help on my problem which is:

I am going to build a side extension which is 2 storey, all planning has been passed.
the extension will be up to the boundry,
my neighbours house is 1.6m approx higher than mine from my damp course to theirs .
we are on a hill and i have to dig down for my footings but because my boundry is only about 1.4m from my neighbours house do i have to expose their footings as to ake sure i dont undermine them? ,
or can i shore their soil up and dig my footing then fill back in when built to their ground level.
Would B.C.O give me advice on this?
I know there are a lot of questions here but i would be thankfull for advice on my options as im not sure where to go on this.

Thanks

Jsmithy.

 

[^woody^]

I don't think that any BCO would give you advice on this due to liability issues

You do need advice though, take heed of this www.diynot.com/forums/building/wolverhampton-collapse.314210

 

[Jsmithy]

Thanks for the link woody,
i realise this could be a nightmare
Where or who would be best to advise me on this?
all the lads i have worked with havent come across such a problem and therefore dont have the expirience happy to advise.
I am sure that the neoghbours footing will be at a simalar level to mine as my footing is only 4 bricks down from my dpc
and the houses are only3.6 m apart from back door to back door.

 

[Jsmithy]

I have quoted this text from the link woody has posted

On our most recent project we had to dig a 1.5m deep foundation directly adjacent to the neighbouring building for a distance of 5.5m. Our dig exposed their footing and went below it by a good 900mm.

We decided to dig and concrete in stages. Once a section of foundation was dug we would hammer rebar into the soil so that there was 500mm of bar both in the exposed pit and into the soil of what would be the next part of the footing.

Worked ok. BC was happy.

noseall could i be so cheeky as to ask how you did this? on my plan the exterior wall which will beholding back the soil and the existing neighbours footing?
is right up to the boundry and to be tanked.
Would the wall need to be brought up in stages and back filled as not to disturb anything?

Thanks in advance for help. View media item 43498 [/img]

 

[Jsmithy]

I have added an old pic of my house (on the right ) and the neighbours,
this may help with my explanation,
i have already exposed the footings on my house and removed some of the stone wall between the houses and the red brick wall is where my boundry is.

Thanks.

 

[jeds]

This depends on too many factors to safely get it right over a forum. You need to know the type and condition of foundation beneath your neighbours house and the depth. You also need to know the type and condition of the soil and the total depth of your proposed foundation. When you have all that information you (or your structural engineer) should prepare a structural design and serve a party wall notice on your neighbour.

 

[Jsmithy]

Thanks jeds

I have got the bco coming out weds morning and getting as much input from him as i can and then i can take the appropriate action,
I have had to get on to the firm who did my plans to draw up a retaining wall suitable to hold back the earth as the first effort was a normal cavity fill tanked wall.
When i get the info from the bco and engineer i will keep posted about the outcome,
Thanks.

jsmithy

ps anyone who has had this problem-input appreciated.

 

[Jsmithy]

double post

 

[Jsmithy]

I have got se to do plan for a 300mm block wall with 100mm cavity with a393 mesh in the cavity filled with 10mm c35 concrete,
i will be mixing this at 1cement 1.5 sand 2.5 aggragate.
The footing will be 20mm c25 concrete, would this work out at 1 cement to 4 or 5 parts ballast?

The footind is 1.2m wide and will have mesh top and bottom with t10 rebar running into the cavity.