Conservatory foundatios.

[Shytalkz]

If it's fill, it should not be used to take strip foundations. The reason for this is that settlement is uncontrolled. The exception to this would be engineered fill, but even then some form of ground stabilisation measure would be used. Or possibly a raft foundation.

30 years on, obviously a fair amount of compaction would be expected to have occurred, but....

I presume that this is a subbie working to a price for the conservatory company and is putting a foundation in purely in accord with the GGF details, as he won't get any extra for extra dig.

The vibes you are giving, bit by bit, are not good....

 

[Tristar]

As I knew this was made up ground, I got the supplier to sign a statement that this would be taken in to consideration when constructing . However, as it does not come under BR's I suppose he can use that as an excuse for not going further. I would be willing to pay the subbie extra to go down further if you guys think it is necessary. Better safe than sorry. Does the rule about 225mm concrete footings apply however deep the trench is? Obviously there will be extra blockwork to pay for also.

 

[^woody^]

Do you know how deep your house foundations are?

I wonder if a 600 wide strip would be better than digging them deeper?

But I think you may be worrying too much

 

[Tristar]

I think the extension foundations are about one meter deep, but I do remember the BCO insisting on steel reinforcement. However, the ground was made up in 1976, and seems fairly well consolidated now.

I am trying not to worry, but just gauge the measure of the general opinion of the experts, for which I am, as always, exceptionally grateful.

Having slept on it, I am inclined to accept the current depth of trench, with the two step option described. The brickwork is to be tied into existing with wall plates.

 

[Thermo]

dont get too hung up on it tristar, its a conservatory dwarf wall, not a house wall

 

[Tristar]

Thanks Thermo, no I'm not that concerned, as I said, just wished to get the widest possible input, then make a decision, based on that and my own observations.

Cheers

 

[Thermo]

have a bit of trust in your builder as well, thats why your employing him

 

[Shytalkz]

dont get too hung up on it tristar, its a conservatory dwarf wall, not a house wall

Unfortunately, that is precisely the approach that most conservatory companies take; precisely why all conservatory work should be subject to BRegs; and precisely why I have a never-ending supply of conservatories built in such a way that need sorting out, inevitably ending up in court.

You seem to infer that, in some way, it's less important for a dwarf wall (or the conservatory as a whole) to be founded on decent ground, when it's a case of precisely the opposite being true, as there is less capability of the wall to attempt to arch over any soft cráp.

It's a structure, it requires a decent founding soil, end of.

 

[Shytalkz]

have a bit of trust in your builder as well, thats why your employing him

You mean the subby employed by the conservatory company, on a fixed price, always being paid at least one or two jobs behind. Yep, trust him implicitly to make the right decision...

 

[Tristar]

Thanks to everyone who has contributed.

I have decided to ask for the footings to go down to at least 1 meter, and widened to 450mm to allow 100mm each side of the wall. Although the supplier signed a document agreeing to construct the conservatory in accordance with the industry best practice, (and all the sites I have looked at recommend 1000mm deep footings) I will offer to pay half the extra cost of going deeper. Getting it right now is more important than the cost of repairing it later.

 

[Shytalkz]

Getting it right now is more important than the cost of repairing it later.

You got it in one!

 

[Shytalkz]

...agreeing to construct the conservatory in accordance with the industry best practice...

That'll be the GGF typical details then - although that doesn't recommend 1m depth from memory (I can't remember the exact details, I've got it somewhere in a job file where it all went Pete Tong for the contractor). 600mm can be perfectly adequate in the right soils; conversely 1m can be a complete waste of time in inappropriate ones. The GGF detail makes no distinction.

 

[Tristar]

In the last five minutes I have spoken with the supplier who is unhappy with the depth and width, and is going to instruct the builder to go down to at least a meter.

I have to say I am very happy dealing with this supplier, but as he says, he can't be on every site checking builder's work, and relies on observant customers to pick up these lapses.

Thanks again for all help. no doubt, like Gen. Douglas MacArthur, I shall return.

 

[Shytalkz]

...he can't be on every site checking builder's work, and relies on observant customers to pick up these lapses...

Words fail me, that is complete and utter bawliks. And you trust this bloke?

 

[Tristar]

A poor choice of words, on my part. He was quite happy that I brought this to his attention, and phoned me immediately he was aware of my concern to assure me that the foundations were not satisfactory based on my comments, and that he would talk to the builder before tomorrow.

And yes I do trust him, having dealt with him since last September, I am quite confident that he wishes to provide a good service.