Soil survey

[ianfish]

HELP!

 

We have engaged an architect who has come up with some strong designs for us.

 

We are adding a decent sized extension and summer house on to what seems decent land.

 

The block provider has suggested we work with a SE and to get a soil survey 

 

The loose quote we just had for eight holes is £4800?

 

What are peoples thoughts

 

We were not expecting a fee in that range.

[PeterW]

10 minutes ago, ianfish said:

The block provider has suggested we work with a SE and to get a soil survey 

 

By who..? Where in the UK are you, what is the soil like in the garden and how old is the current property..??

[AliG]

I just had a soil survey done in Edinburgh. I had a guy recommended on here at just over £1000, but he wasn't available. I basically went on Google and sent the same email to five companies.

 

Two came in at over £4000, two at around £2500 and one said they didn't do it, but recommended me a company who did it for just over £1000. I am still waiting to see the report before I recommend them to anyone. The high quotes often had absurd padding in them, such as £350 for a utilities report, even though it is on garden ground and I have a map of what is under it, or hundreds for H&S assessments etc.

 

I would just send out asking for quotes, they all came back in a couple of days. I only needed 3 holes, so you might be nearer to £2000 or more if they need to know what is under the site before they drill.

 

I paid over £4k for one arranged via an SE four years ago, when I looked back at it, around £1000 was because they weren't local and charged me for travel and subsistence, so I only checked local people this time.

 

Edit - Just had another look at your original post. Why would you need 8 holes for an extension, that is crazy. I doubt most people have anything for an extension, they probably just dig down and match the existing foundations.

 

 

Edited August 4, 2020 by AliG

[ianfish]

We are looking at a raft 

 

And in essence two structures 

 

But ones a summer house a big summer house but nothing out the ordinary

[AliG]

I assume that the SE is OK with a raft attached to your house which has a different kind of foundation? I guess this may need a couple of holes and maybe one extra one where the summer house goes. A summer house is likely to be a light wooden structure and probably doesn't need a soil survey at all, but if they are already on site, an extra hole won't cost much. Did the surveyors recommend 8 holes or the SE? The standard is 3-4 holes for a new house.

[Mr Punter]

If you are getting a local builder they may have a good idea of ground conditions / foundations needed.  If not, ask Building Control.

[JamieG]

3 hours ago, AliG said:

I just had a soil survey done in Edinburgh. I had a guy recommended on here at just over £1000, but he wasn't available. I basically went on Google and sent the same email to five companies.

 

Two came in at over £4000, two at around £2500 and one said they didn't do it, but recommended me a company who did it for just over £1000. I am still waiting to see the report before I recommend them to anyone. The high quotes often had absurd padding in them, such as £350 for a utilities report, even though it is on garden ground and I have a map of what is under it, or hundreds for H&S assessments etc.

 

I would just send out asking for quotes, they all came back in a couple of days. I only needed 3 holes, so you might be nearer to £2000 or more if they need to know what is under the site before they drill.

 

I paid over £4k for one arranged via an SE four years ago, when I looked back at it, around £1000 was because they weren't local and charged me for travel and subsistence, so I only checked local people this time.

 

Edit - Just had another look at your original post. Why would you need 8 holes for an extension, that is crazy. I doubt most people have anything for an extension, they probably just dig down and match the existing foundations.

 

 

I'm about to start a build just outside Edinburgh and planning requires some test holes so would be grateful if you could share your contacts once you have your report back and are happy with it. 

[ianfish]

Right rang local building and they jokingly asked why id started planning a housing estate!

 

He also sort if suggested for what reason did the system require so many samples?

 

If the raft was designed ok and the structural engineer had specified the amount of steel and maybe more concrete what real purpose would 8 bores do.

 

Looking through the quote the supplier is looking at in the first instance of 2.5k for delivery of icf blocks and insulation. 

 

Im feeling a bit mugged of..the volume of delivery i dont think justifies 2.5k

 

 

 

 

[ianfish]

3 hours ago, Mr Punter said:

If you are getting a local builder they may have a good idea of ground conditions / foundations needed.  If not, ask Building Control.

I was looking at doing stuff myself....

 

As much as was possible anyway..

[AliG]

1 hour ago, JamieG said:

I'm about to start a build just outside Edinburgh and planning requires some test holes so would be grateful if you could share your contacts once you have your report back and are happy with it. 

Will do once it comes through and I am happy with it

 

[JamieG]

On 04/08/2020 at 18:46, AliG said:

Will do once it comes through and I am happy with it

 

Were you happy in the end with your soil survey? If you were would you mind sharing the details? Hoping to get a soil survey done soon. 

[AliG]

Sorry @JamieG I was and I should have reported back. The SE did describe it as a bit brief, but it was al that was needed for the foundation designers.

 

The company who did it was called Aitken Labs in Falkirk.

 

I have booked them in to do a percolation test for a soakaway now.

[MortarThePoint]

How deep are the bores @ianfish ? I don't know what area you're looking to build over, but 8 seems like a lot. We had four sampled down to 5m, one of them went further but I can't remember how much. Percussive window sampling is pretty cool and you get to see what's down there and the lab analyses it in various ways. You get some instant results in the form of SPT data which is effectively how many knocks of the coring tool does it take to move a fixed distance (knocked by a known weight from known drop). You'll want to know the Plasticity Index as well, particularly if there are trees nearby.

 

Careful with local knowledge as it's easy to be near a boundary like we are.

[Declan52]

1 hour ago, MortarThePoint said:

How deep are the bores @ianfish ? I don't know what area you're looking to build over, but 8 seems like a lot. We had four sampled down to 5m, one of them went further but I can't remember how much. Percussive window sampling is pretty cool and you get to see what's down there and the lab analyses it in various ways. You get some instant results in the form of SPT data which is effectively how many knocks of the coring tool does it take to move a fixed distance (knocked by a known weight from known drop). You'll want to know the Plasticity Index as well, particularly if there are trees nearby.

 

Careful with local knowledge as it's easy to be near a boundary like we are.

The joy wears off really quickly when your listening to that banging every hour of every day!!! But I did get to travel all over the country.

[ianfish]

On 03/10/2020 at 14:55, MortarThePoint said:

How deep are the bores @ianfish ? I don't know what area you're looking to build over, but 8 seems like a lot. We had four sampled down to 5m, one of them went further but I can't remember how much. Percussive window sampling is pretty cool and you get to see what's down there and the lab analyses it in various ways. You get some instant results in the form of SPT data which is effectively how many knocks of the coring tool does it take to move a fixed distance (knocked by a known weight from known drop). You'll want to know the Plasticity Index as well, particularly if there are trees nearby.

 

Careful with local knowledge as it's easy to be near a boundary like we are.

a little bit of over egging a project it seems... the advisor who suggested 8 no  longer works for the parent company ...make of that what you will

[SuperJohnG]

Just to throw something in here for anyone who finds this. 

 

These prices are crazy, I jad a soil survey done for 350,.paid a jcb driver 100 quid to turn up an dig 5 holes for 2 hours and backfill. Full soil investigation survey supplied in a couple of days. 

 

Unless you're needing ti do boreholes for whatever reason it's crazy money. 

[TonyT]

I was £900 for my soil survey, foundation, wall, roof design from the SE.

[ianfish]

18 hours ago, SuperJohnG said:

Just to throw something in here for anyone who finds this. 

 

These prices are crazy, I jad a soil survey done for 350,.paid a jcb driver 100 quid to turn up an dig 5 holes for 2 hours and backfill. Full soil investigation survey supplied in a couple of days. 

 

Unless you're needing ti do boreholes for whatever reason it's crazy money. 

 

 

It was a very loose @iss take by a chancer...

 

One survey can cost 350 ish. 

 

The advisor wasnt very good at advising.

Oddly we never heard from him again. despite his he had a mate who could sort it for us asap....

 

 

[oldkettle]

Hi @ianfish , @TonyT

 

Where are you located? Just had a quote for a soil survey for our garden building. There are plenty of houses around including our bungalow which is fine with a 1m foundation and doesn't mind old conifers around. Despite BC saying it's a sandy clay mix low to medium shrinkabilty the surveyor says 4 holes 3m deep, £1500 plus VAT. I wonder whether we can get it done cheaper in Surrey. 

[ianfish]

16 hours ago, oldkettle said:

Hi @ianfish , @TonyT

 

Where are you located? Just had a quote for a soil survey for our garden building. There are plenty of houses around including our bungalow which is fine with a 1m foundation and doesn't mind old conifers around. Despite BC saying it's a sandy clay mix low to medium shrinkabilty the surveyor says 4 holes 3m deep, £1500 plus VAT. I wonder whether we can get it done cheaper in Surrey. 

is this for calculations or for a screw foundation?

 

We have been told the need for two soil surveys for a domestic build is extremely rare 

[Declan52]

Unless you need to go beyond 3m due to a risk of peat,silt or possible contamination etc there is no real need for boreholes. For anything else a 3.5t mini digger is more than capable of doing the job. But you do need some one there who can examine the spoil as it comes out and tell you what it is and if it's suitable to build on.

[oldkettle]

4 hours ago, Declan52 said:

Unless you need to go beyond 3m due to a risk of peat,silt or possible contamination etc there is no real need for boreholes. For anything else a 3.5t mini digger is more than capable of doing the job. But you do need some one there who can examine the spoil as it comes out and tell you what it is and if it's suitable to build on.

 

Thank you Declan

 

3.5t digger is too wide for our existing passage, only have about 1.20m. Thought I could dig 2m with a 1.5digger then use an auger. The question is whether it's good enough for an SE: I was asked for "factual and interpretative report for a potential insulated raft foundation, soil parameters, ground water and shrinkability of the soil as well as desiccation". I must admit this particular SE was talking about screw piles, no idea why - as I said, no existing house needed those. 

Edited March 5, 2021 by oldkettle

[oldkettle]

6 hours ago, ianfish said:

is this for calculations or for a screw foundation?

 

We have been told the need for two soil surveys for a domestic build is extremely rare 

This is only for the survey, SE wants this before proceeding. I actually asked the surveyor whether 4 holes were needed and he just said yes. 

 

I didn't mention it to the surveyor but SE did suggest screw foundation. Don't know, maybe they talked directly. 

Edited March 5, 2021 by oldkettle

[ianfish]

Just now, oldkettle said:

This is only for the survey, SE wants this before proceeding. I actually asked him whether 4 holes were needed and he just said yes. 

 

See what your local BC says.

 

A now ex employee of a company we were thinking of using suggested six for a single story 5m x12m extension.

 

I rang BC and asked what they would advise, he was dry but asked was I doing a hosing development or car park he was unaware of.

 

Do one and then go from there I have been told since, if you need more than two something is a miss and a raft may not be the best option.

[Declan52]

What you dig out of the ground is classed as a disturbed sample so you can perform any worthwhile test on it for it's bearing capacity. If the structural engineer wants this type of data then it has to be boreholes and spt tests.

You could ask the company for a quote just to use dynamic probing. This just involves driving a long thin metal pole into the ground and count how many blows it takes to get a certain distance,1m intervals usually.

But if they want data and specific soil samples at 2m,3m  depth then it's boreholes. 

So might be worth asking if just data from dynamic probing will be enough or what exactly does he need to do this job.