Just how difficult is excavation work?

[flanagaj]

Maybe I am not doing it justice and am massively over simplifying things, but if you consider that every aspect of groundwork is carried out relative to finished floor level,then it seems very straightforward to do all groundworks yourself.   One you have used simple trigonometry to mark out your footings you dig to the required depth (according to soil survey) and relative to finished floor level. Put pegs into the side of the trench according to required concrete depth.   Calculate required concrete volume and poor footings, levelling to pegs.

 

If you buy a decent rotary level and you understand about drainage then you can then install the foul water system to septic tank and the required drainage field.

 

The only part that I'm unsure about is being able to operate the excavator to create a flat bottomed and levelled trench.   

 

I could potentially get the digger and maybe practice on some smaller areas first so as to get familiar with it.  Was thinking about site entrance.

 

Have any forum members done this, and if so, would you advise against or say that it's very viable.   I've got plenty of time that I can devote to getting the groundworks done.

[Roger440]

Its viable

 

But dont underestimate how crap you will be with a digger first time out.

 

Creating a neat level trench isnt as easy as a good operator will make it look. And if your trench is all over the place, you will munch up a load of extra concrete.

 

Ive done a lot of diggering. Not sure even now i could do "nice" trnches for foundations.

[Gus Potter]

24 minutes ago, flanagaj said:

I could potentially get the digger and maybe practice on some smaller areas first so as to get familiar with it.  Was thinking about site entrance.

Advise you don't do this.. you'll make more of a mess and it is not worth it.

 

Find a local digger driver who knows what they are doing and is used to working with your soil type. Pay them well and they will give you all sorts of other tips about drains etc.. the founds and with a couple of bacon rolls even more. They could also tell you what ground workers to avoid and who is good locally.

 

I love working with local digger drivers etc as they are doing this day in and out.. they hear what past SE / Goetec Enginners have been telling them and can "feel the ground and see" with their machine. Why not rely / take into account on their local knowledge? It's a no brainer for me!

 

I always want to work with an experienced local machine driver when doing say trial pits or doing founds.. they have saved my bacon on occasions!

 

I know you are thinking you may make a saving getting a machine yourself.. but look at this holistically and the advice you may get.. also you'll get a found in the right place. Digging founds is not easy as you have have a digging strategy.. so you don't box yourself in.

 

Also if you want to have a go yourself then there is a soil bulking factor.. what you dig out grows a lot and if you don't stockpile it properly and seal it ( a skill) then later you'll have a harder job to handle that.

[ProDave]

I did my own. I bought an old Komatsu 3ton tracked digger.  Digging foundations needs a bit of thought as you want to dig them in an order that avoids you tracking back over a finished trench, and working out how you are going to shift the excavated soil and where are you going to store it for re use or muck away.  And the depth is not always constant, it is usually once you pass through the top soil into the harder sub soil, which may not be the same depth all over especially on a sloping site.  There you want to step the bottom of the trench not make it sloping.

 

Drains are easy it's the working out how to get a downhill fall all the way without it being too shallow or too deep.  That is something you need to work out on paper, not in the seat of the digger.

 

Also be sure before you go down this route your builder is happy for you to do this work.

[nod]

I’ve dug two lots of Groundwork’s out with zero experience 

A very good friend showed me how to operate the machine 

The only issue I had on the first was that I was far to slow at loading the muck away Wagons want to be away in 15 minutes I brought my mate back a couple of times 

 

This time I borrowed a five tone digger equipped with GPS 

No lines or pegs Just follow the sat nav It even tells you the depths 

Amazing bit of kit 

Drains are common sense and should be done with slab But are hardly ever done this way on large sites 

Take your time 

 

[Tetrarch]

I've literally just spent the last 8 days watching the foundations dug for our extensions and soakaways. The level of skill needed to accurately dig a straight and level trench is extremely high. It's not a job I would even consider doing myself. 

 

Regards

 

Tet

[flanagaj]

It's not so much about saving money, but mainly due to wanting the job correctly.  I have used multiples trades in the past when we renovated our house, and 50% of them were ****.   Maybe I get a good digger driver in to pull the footings and I can then do the drainage myself.  As @ProDave stated.  Drainage is planned on paper and all relative to the height of the excavated oversite.   If you hammer a stake into the ground and get it set to finished floor level, and use this as you reference point for all laser level measurements, how can you possibly get things wrong?

 

 

[flanagaj]

11 minutes ago, nod said:

I’ve dug two lots of Groundwork’s out with zero experience 

A very good friend showed me how to operate the machine 

The only issue I had on the first was that I was far to slow at loading the muck away Wagons want to be away in 15 minutes I brought my mate back a couple of times 

 

This time I borrowed a five tone digger equipped with GPS 

No lines or pegs Just follow the sat nav It even tells you the depths 

Amazing bit of kit 

Drains are common sense and should be done with slab But are hardly ever done this way on large sites 

Take your time 

 

This is a confidence builder.  The depth display is a very cool feature.   I suppose using triangulation with satellites for GPS is actually very accurate. 

[Tetrarch]

sorry - wrong thread

Edited February 24 by Tetrarch
wrong thread

[saveasteading]

17 minutes ago, flanagaj said:

how can you possibly get things wrong?

It's one of those things you fully understand or don't. I've seen so many level errors, costing money and reducing quality, usually by people who think it's easy.

If you really understand it and can do the sums, its only plus and minus on the hoof, then great. It may be trickier than you think. 

If putting in a 300 deep footing and you take out just 50mm too much, that's 17% waste....criminal. 100mm ouch.

Practice levelling around the site first, perhaps a survey and a pretend drain run, or you'll slow down the professional operator.

[joe90]

Well I had my own JCB and got quite good at using it but on the advise of my builder we got a local retired old boy who had been doing it for years to dig the founds and he was so accurate and quick it was worth paying him (a little). I think it depends on how confident you are and the impact of getting it wrong. I tried to limit my work to what I knew I was good at. ( I gift my kicks out of digging trees out and drain trenches)

[flanagaj]

3 minutes ago, saveasteading said:

Practice levelling around the site first, perhaps a survey and a pretend drain run, or you'll slow down the professional operator.

That's a good point.

[joe90]

27 minutes ago, flanagaj said:

how can you possibly get things wrong?

Wrong levels, sides collapsing, wrong location, uneven base 🤷‍♂️, yes stick to less important holes in the ground. Then again being devils advocate, I get a great kick out of doing work myself so if you want to do it then go ahead.

[nod]

41 minutes ago, flanagaj said:

This is a confidence builder.  The depth display is a very cool feature.   I suppose using triangulation with satellites for GPS is actually very accurate. 

Yep

Your working to the Topo survey 

I had an 80 meter drain to dig across the fields With a fall of 600 mil

The bit of kit bleeps when you hit your depth 

 

[flanagaj]

18 minutes ago, joe90 said:

Wrong levels, sides collapsing, wrong location, uneven base 🤷‍♂️, yes stick to less important holes in the ground. Then again being devils advocate, I get a great kick out of doing work myself so if you want to do it then go ahead.

Wrong levels, sides collapsing, wrong location, uneven base.  Aside from the second point, the rest are avoidable.

[joe90]

28 minutes ago, flanagaj said:

Aside from the second point, the rest are avoidable.

Then crack on! I am just saying I have been there and it’s not as easy at it looks (but can be great fun) 👍

[saveasteading]

7 minutes ago, joe90 said:

not as easy at it looks (but can be great fun) 👍

Bottom line. Diy digging  won't save money unless you have an incredible knack.

If you have the line and level marked out then the professional will be in and out in 1/4 of the time you'd take. But if youre bumbling along then diy may be worthwhile.

Everything looks easy done by an expert.

Not everyone with a digger is good at it, or understands construction.

You pay for the muck away and concrete.

Surprisingly few people can do levelling properly.

GPS is for motorways. For a house use quality tapes, and especially Pythagoras to check the square.

[joe90]

19 minutes ago, joe90 said:

Then crack on! I am just saying I have been there and it’s not as easy at it looks (but can be great fun) 👍

To expand on that my build was a conclusion to a life of DIY and doing houses up, never built a complete house before and I loved every minute of it (retired, funds available, no pressure) and a love of doing things myself. I loved the JCB, did lots of jobs around the site, great fun. However most here are not in that situation (I believe) and are controlled by finance, time scales and family/work commitments. So what I am saying is even I, who wanted to do everything myself, delegated (paid) for certain works to be done so I could concentrate on the stuff I was good at/enjoyed. 

[Mr Punter]

I would always get an excavator and experienced operator.

 

We did a basement once on a very restricted site and the operator - the son of the plant hire owner - made it look so easy.  He just knew where the machine should be, where to stack the spoil for muckaway. Even with practice I would not have been able to do it and may have ended up in the hole.

 

For tricky layouts I like to get the guys who do the topo survey back to mark the building corners, then again to mark on the foundations for the brickwork.

[joe90]

However @flanagaj don’t let us spoil your fun if you want a go, if you do it and get it right you will be dead chuffed with yourself. As I am renowend fir saying “what could possibly go wrong 🤷‍♂️”  

Edited February 24 by joe90

[dpmiller]

1 hour ago, nod said:

Your working to the Topo survey 

I had an 80 meter drain to dig across the fields With a fall of 600 mil

The bit of kit bleeps when you hit your depth 

 

So now we *need* a topo survey and to hire a fancypants modern machine with full-on GPS bucket system. How much extra will that be? Who will program the GPS and who is liable if it's done wrong?

[nod]

I’m not sure about the machine as I borrowed mine from a friend 

You should really have a Topo prior to house design Mine cost 500 for a 2.5 acre site in 

[MAB]

Dug my own foundations for a side extension with help from an 'old school' Builder friend who said we could do it without a Mini digger in a few days.....1 metre deep in clay and we just did it with spades and wheelbarrows in 2 sections to make sure the concrete went in before any rain arrived. We also mixed our own concrete in a standard mixer. It was nearly 20 years ago and you need to be fit with good dry weather for digging clay....was easier than I thought but I could not do it now though! 😄

We hit the water table at 1 metre and the following morning there was 6" of water in the bottom of the foundations despite no rain for days but the Building Inspector said pump or bail the worst out and to use a drier concrete mix for the first few barrow loads that went in. He also wanted rebar put in the concrete where the two new foundation sections were to join plus a thick sheet of polystyrene between the existing 1930's house foundations and the new extension foundations.

Edited February 24 by MAB

[George]

12 hours ago, flanagaj said:

It's not so much about saving money, but mainly due to wanting the job correctly.  I have used multiples trades in the past when we renovated our house, and 50% of them were ****.   Maybe I get a good digger driver in to pull the footings and I can then do the drainage myself.  As @ProDave stated.  Drainage is planned on paper and all relative to the height of the excavated oversite.   If you hammer a stake into the ground and get it set to finished floor level, and use this as you reference point for all laser level measurements, how can you possibly get things wrong?

 

 

Out of almost all the trades I tend to find groundworkers some of the best. I think it doesn't attract cowboys - it's blokes who like diggers and digging. 

[Conor]

My mate owns and runs a ground works company. His mates rate for him and his machine and accessories is £55/HR. Worth it. I do some diggering, and I'm planning doing some grading, garden wall founds, and landscaping next week. Will be about the fourth time I've hired a machine for a week or so. You do get the hang of the basics pretty quickly, like skiing, but I'm not tackling a black run any time soon. He can do at least twice the work I could do in a day, and far higher standard. Same as any trade really.

Edited February 24 by Conor