Pre Fab building no foundations?

[dannewhouse]

has anyone ever had anything to do with one of these?

I have a planning application in and they are wanting a CMRA Coal Mining Risk Assessment and will probably want some bore holes doing, I don't quite know what these will cost?
we are debating whether we can use one of these pre fab buildings which just bolt to a concrete pad but haven't had anything to do with them other than there is one on site for the same reasons we are hitting now. building is 30x45x 16 to eaves.

we might put a building up in the future so it could be worth having the bore holes etc done just looking at options open to suggestions.

 

[TheTallGuy]

Depends on the ground structure to start with. I know of one building that's been up for 60 years with no foundations but no signs of stress, whereas a 10 year old build on a rafted foundation about 2 miles away keeps having to be repaired as the raft keeps shifting and moving the loadings.

 

[dannewhouse]

Depends on the ground structure to start with. I know of one building that's been up for 60 years with no foundations but no signs of stress, whereas a 10 year old build on a rafted foundation about 2 miles away keeps having to be repaired as the raft keeps shifting and moving the loadings.

I'm pretty damn sure that the ground is ok as there is umpteen houses within metres of the site which aren't showing signs of any problems just reluctant to pay for boreholes etc for nothing in my eyes.
annoying thing if it had been agricultural over the boundary I dare say non of this would be needed! 2 great wind turbines and no boreholes or CMRA for them! just annoys me a bit. (no point getting angry or owt with council though as they'll just do there best to stop it any way)

 

[Forever Fendt]

The coal authority have certain criteria for buildings with no foundations so the floor slabs to be self supporting and free spanning for 6m cantilever so not really doable in most cases

 

[MickMoor]

I have a good, reasonable structural engineer from Sheffield designing a tank foundation for suspect ground conditions East of Hull. I was led to believe all that twaddle about boreholes etc., but he said "Why? Just plate tests for ground bearing pressure. I recommend XYZ from Doncaster" About a tenth the cost. PM if you want contact details. In my experience, the normal thing that happens around your area is that settlement sometimes makes drains run the wrong way.

 

[dannewhouse]

I have a good, reasonable structural engineer from Sheffield designing a tank foundation for suspect ground conditions East of Hull. I was led to believe all that twaddle about boreholes etc., but he said "Why? Just plate tests for ground bearing pressure. I recommend XYZ from Doncaster" About a tenth the cost. PM if you want contact details. In my experience, the normal thing that happens around your area is that settlement sometimes makes drains run the wrong way.

the borehole bulls**t Is for planning not the actual foundation design the annoying thing is I can 99.9% tell you what the bore holes will show. odd seam of coal within top 10m nothing major max 6" lower down there might be a decent seam or 2 perhaps 1m 1 or 2 of these might have been mined out thus being a void. the report will say as these workings are so deep they should be of no concern to the development etc. just ££££ for nothing much!

 

[MickMoor]

I would ask the planners why they need boreholes, in a friendly way, sounding as if you are really interested in the whole process, it might sharpen their minds if they have to justify it. The integrity of the structure is not normally a planning matter, only the effect of the new building on the environment.
If you need his opinion, this is why he impressed me. I had received a quote for boreholes, as you probably know, running into thousands.
" I have some experience of working in the area - south of the river - where it is silty. However, whilst information on ground conditions is important, the quote you have received seems OTT for our purpose. What we require is the load carrying capacity of the substrate to enable the design of the raft. Therefore, I suggest you dig trial pits, say three spaced out within the footprint of the tank. Sketch out the positions and number them for reference. Take samples of the substrate from each at depth of about 600mm (which is I guess where the raft will be based). The lab I use is XXX - The lab. Manager is Clive on 08XXXXX - he will be able to give you a quote for the testing. Last time I had work done it was £110 plus VAT!
Since a cubic metre of water weights one metric tonne - and the tank will have a maximum height of 5.6m, the maximum load which will be applied to the ground will be 5.6 metric tonnes/sq m.
I have arranged with XXX that they will load the plate incrementally 2 tonnes at a time, up to a maximum of 10 tonnes. Providing the settlement is within limits acceptable to you, this will equate to a Factor of Safety of about 2.
They have said, in view of the relatively light loading, that a JCB will be adequate for the operation."

 

[Forever Fendt]

I would ask the planners why they need boreholes, in a friendly way, sounding as if you are really interested in the whole process, it might sharpen their minds if they have to justify it. The integrity of the structure is not normally a planning matter, only the effect of the new building on the environment.
If you need his opinion, this is why he impressed me. I had received a quote for boreholes, as you probably know, running into thousands.
" I have some experience of working in the area - south of the river - where it is silty. However, whilst information on ground conditions is important, the quote you have received seems OTT for our purpose. What we require is the load carrying capacity of the substrate to enable the design of the raft. Therefore, I suggest you dig trial pits, say three spaced out within the footprint of the tank. Sketch out the positions and number them for reference. Take samples of the substrate from each at depth of about 600mm (which is I guess where the raft will be based). The lab I use is XXX - The lab. Manager is Clive on 08XXXXX - he will be able to give you a quote for the testing. Last time I had work done it was £110 plus VAT!
Since a cubic metre of water weights one metric tonne - and the tank will have a maximum height of 5.6m, the maximum load which will be applied to the ground will be 5.6 metric tonnes/sq m.
I have arranged with XXX that they will load the plate incrementally 2 tonnes at a time, up to a maximum of 10 tonnes. Providing the settlement is within limits acceptable to you, this will equate to a Factor of Safety of about 2.
They have said, in view of the relatively light loading, that a JCB will be adequate for the operation."

Mick your are being logical here but remember it is planners we are dealing with and common sense does not prevail,In certain areas the planners have to consult with the coal authority who require a CMRA and depending what this says they attach conditions to the planning permission to do intrusive investigations in the form of bore holes at 30m deep and any voids will need pressure grouting to stabilise the ground at massive costs this is before the development can begin and you have to pay them £235 for a permit to drill on top of all other costs