Trial pits for structural engineer

[Nokidsyetnet]

Hi,

Very new to this whole construction thing and some advice is needed.
We are about to employ a structural engineer to do the calculations (but not drawings) for our extension. He needs two trial pits dug to view the existing foundations.
Both pit locations are currently concreted over but we don't really want/need that to be made good as we are demolishing everything in that area soon to build the extension.
The building firm suggested by architect want over £1000. I asked for a break down and it was to send 1/2 men on one day to dig, then 1/2 to be available on the day of the SE coming to dig any additional holes, backfill and to reinstate the patio.
Allowing £200 for materials (unwanted concrete to reinstate patio) that is at best case scenario £250 per (part) day per man. I am in SE is that really the price of labourers?
I know you can't extrapolate a small job day rate to a big project but I am now terrified that we can't afford our extension if these are the prices we will face.
Does it sound reasonable to you guys? Is there anything we can do to reduce the price? I am thinking of suggesting that they come early on the one day and do it all on the same day and that they don't do the concreting.
Thanks for any advice

They’ll need to hire plant to break out the concrete and a mini digger to dig the trial pits. These are charged on day rates, and will probably be around £300 + (I am in Yorkshire, so not familiar with SE rates). If they havn’t included these into the break down, they’ll be incoporated into the labour rates.

You do realise that Structural Engineering is a chartered profession ? 4-5 years at university and 5+ years to become chartererer? Architects even more so. Even in the pits are dug by labourers, then the strata will need to be examined and analysed by the engineer. Have they mentioned lab testing?

Forgot to say - £1000 for TPS sounds perfectly reasonable.

Here E-SE we pay £175-225 a day for builder, carpenter, slightly more for electrician and plumbers. Does that help ?

Disagree, we recently paid £100 to have a trial put dug. Took one labourer 4 hours to do including breaking up the concrete and hand digging the pit.

Took him 5 mins to back fill the hole afterwards.

Thank you for the insight knowing the digger cost makes things more understandable.

The SE is charging an additional £1800 for the calculations and the architect an additional £1000 for the drawings. I don't mean to belittle their work as I couldn't do it myself. I also don't mean to belittle the work of the labourers as I could not do that either.
They probably won't need soil samples as bore holes were drilled a few years ago after a drainage issue.
Thanks for reality check

Also in SE if it helps with Surrey tax on top.

Sorry missed the other messages. It is hard to know what is right when you have such varied quotes will call a few more firms maybe a smaller company would be better.

Thanks for the replies

We paid about £100 for one, but backfilled it ourselves. Backfilling took a while as we stopped every 6 inches to compact it properly. Not difficult though.

SW London, fairly large firm and we charge £100 per pit if we're already on site or about to go on site.

Although it's hard to judge a firm's pricing structure on just one element - they may be more reasonably priced on other elements of your build. Have you actually appointed the building firm or are they doing the pits as a one-off job? That would affect the price, too.

Update, we haven't appointed a firm yet but have had another quote from a local firm. £250 refundable if we use them for the extension.
The difference in price is over £1000 which is really worrying.
Cheaper firm are local good reviews on Facebook came out to look and said a couple of guys hand dug.
More expensive say 2-3 guys and a digger because they don't know what they will find under the concrete.
Advice welcomed, how do you decide between two just different quotes!

Watching with interest - good luck, OP!

Im in a similar line of work to Bike Run.

I’d say £1k is reasonable for the pits, if I were booking the work I’d be really wary of the cheap quote. (Not that i ever spend my own money on this stuff)

Without examining both quotes in detail I’d be really wary that the cheaper firm are a) desperate for work because they are crap or b) Wildly over optimistic about how they are going to do this or c) haven’t actually got any experience and really don’t know what they are letting themselves in for. All of which can cost you dear.

And of course they could be fine. Just crap at pitching at the market rate (I have worked for a firm like that, and it was bloody frustrating to lose work because people were suspicious)

If I were evaluating these I’d be looking through their paperwork, get a feel for how clued up they were, getting some references and maybe a couple more quotes.

I'm also in similar work and £1k sounds expensive to me. I'd go with the £250. If they are a local firm they should have a good idea of what ground conditions to expect.

Just to update in case anyone has the same query. We did the £250 pits engineer was happy with the them. Took one OAP 5 hours to dig no digger or team of men needed.
Thanks for the advice saved £1010 but already have plans to spend it on a new oven

Hi,

I am also in the South East, Kent and wondering if you can pass on the details of he guy you had to dig the trial pit? Thanks