Foundation for Balcony Leg

[self builder 123]

Evening

We are currently planning to build a balcony from the rear of our house.

The balcony is approx 6m wide x 2m deep going back to the house. It is to be supported at the rear from the gable of the house.

At the front there is to be a vertical timber support at each corner with a laminated timber beam in between. The vertical supports are to be 150mm x 150mm timber.

We had to put in a new footing for one of the vertical supports.

I dug down into the soil ( which drains very well - no clay ) so that the top of the concrete footing was 220mm below ground level.

The actual concrete footing was formed using C35 ready mixed concrete with 2 layers of A142 mesh and measures 900mm long x 600mm wide x 225mm deep. On top of the concrete there are 2 courses of concrete blocks laid block on flat with 3:1 mortar to come up to ground level.

As this will be supporting the balcony in one corner does this footing sound adequate ?

Cheers

 

[Shytalkz]

Yes, providing the ground you cast into is good virgin stuff and not fill.

 

[self builder 123]

Hi Shytalkz

I'm not 100% sure that the soil was not fill put in many years before ???

What remedial action would you recommend ?

Could I dig down next to the footing going deeper and pour in concrete in the front and to the sides making it laterally bigger so that it is less likely to move ?

Cheers

 

[Shytalkz]

If it didn't contain any nasties like topsoil, large lumps of rubble etc, you should be ok.

Now I hope you weren't within 3m of a neighbour and should have served a party wall notice...

 

[hotrod]

 

[self builder 123]

Hi again Shytalkz

If it is fill it was put in about 6 years ago and has been trafficed back and forth over the years plus it has been rained on many many times in the same period.

When I dug down I found course sand and stones, not top soil or any other form of rubble - it was very clean in that respect.

Is there a "belt and braces" remedial approach which I could take to give myself peice of mind ?

Cheers

 

[self builder 123]

Hi Shytalkz

By any chance do you have anymore advice for me ?

 

[Shytalkz]

Sorry, obviously missed the Last Post

From your soil description and as long as it seemed reasonably compact to you, that won't be going anywhere: no need for any remedial work.

As a fine upstanding professhunul engineer I do of course have to tell you that, as this is structural work, you must obtain Building Regulations approval....

 

[self builder 123]

Thanks again Shytalkz

Will have the Local BCO take a look.

Many thanks - much appreciated.

 

[Shytalkz]

Will have the Local BCO take a look

I was joking...!!!!

 

[self builder 123]

Hi

I have uploaded a picture of the footing.

Untitled

• self builder 123
• 20 Jun 2009
• 1

The concrete blocks have been used to come up to what will be the finished ground level.

Any other comments ?

 

[Shytalkz]

Looks fine to me. Should withstand a nuclear war, for sure

 

[self builder 123]

Cheers Shytalkz

The ground material lying around the construction is typical of what I dug out.

Stones and a course sandy material - no top soil and no vegetation. I was paranoid that I did not go deep enough all the way don to virgin formation ?

This area had laid undisturbed for several years and has been rained on many many times, so I believe that it is well settled.

So to close this subject ( I am sure you are glad to hear ) from what you can see is there little risk that this footing could move when the balcony is built ?

I am very grateful for your advice.

 

[Shytalkz]

As long as it was compact with no significant voiding, there should not be an issue.

 

[hotrod]

Untitled

• self builder 123
• 20 Jun 2009
• 1

Any other comments ?

That has a remarkable resemblance to the surface of the moon