Foundation excavation plan.

[flanagaj]

 

My original plan here for excavating the footings is as follows.

 

1). Pull the North footing to depth.

2) Pull the 6 vertical footings to within 1.5m of the South footing

3). Pull the south footing

4). Join up the remainder of the vertical footings with the south footing

 

If I do this or do get the groundworker to do this, it would mean that the North footing will be exposed for a few days before the concrete is poured.  Would people do it this way or would you pour and shutter multiple times to avoid leaving footings exposed for a few days?

[Russell griffiths]

If you’re not driving the digger then your opinion doesn’t matter. 
if you have an experienced operator and a good groundworker then they will know exactly what to do. 

don’t interfere too much, sit on the dumper or work the laser, but trying to over manage lads that do this every day won’t go down very well. 
You won’t know how the corners will hold up until you start, you might come across a big patch of loose backfill,have the shuttering to hand

you will dig all that in two days, you need a site visit the second you get 4-5 m of trench to full depth. 
you do not under any circumstances want to have to go back over it, so you need depth sign off the same day you start. 
 

what do you mean by shutter and pour multiple times. 
that all needs digging in one go and pouring in one hit the following day. 

Edited 15 hours ago by Russell griffiths

[Tony L]

Maybe have a pump to hand too - a proper one that's designed for filthy, gritty water.

[flanagaj]

22 minutes ago, Russell griffiths said:

If you’re not driving the digger then your opinion doesn’t matter. 
if you have an experienced operator and a good groundworker then they will know exactly what to do. 

don’t interfere too much, sit on the dumper or work the laser, but trying to over manage lads that do this every day won’t go down very well. 
You won’t know how the corners will hold up until you start, you might come across a big patch of loose backfill,have the shuttering to hand

you will dig all that in two days, you need a site visit the second you get 4-5 m of trench to full depth. 
you do not under any circumstances want to have to go back over it, so you need depth sign off the same day you start. 
 

what do you mean by shutter and pour multiple times. 
that all needs digging in one go and pouring in one hit the following day. 

Point taken.  I think I've chosen wrong people for this job as there are telling me 10 days all in.  I agree with you.  It's a 2 day job with a decent machine.

 

One groundworker who I didn't use, recommended i pulled and poured the garage first and then pulled the house footings and then joined the old and new footings with rebar resin bonded into the earlier poured footing.

 

 

Edited 14 hours ago by flanagaj

[Oz07]

I think 1 day with a 5 or 6 tonner to standard 1m depth and wouldn't be far off. I'd be digging on one day pouring the next. Concrete in afternoon gives you a buffer of the best part of a day. Maybe with your 2.7 allow 2 days concrete on morning of third.

 

I'm assuming your hiring groundworker and machine separately? Bit late now but for founds I always hire man and machine as a package. 

[flanagaj]

2 minutes ago, Oz07 said:

I think 1 day with a 5 or 6 tonner to standard 1m depth and wouldn't be far off. I'd be digging on one day pouring the next. Concrete in afternoon gives you a buffer of the best part of a day. Maybe with your 2.7 allow 2 days concrete on morning of third.

 

I'm assuming your hiring groundworker and machine separately? Bit late now but for founds I always hire man and machine as a package. 

I'm going to bin off the chap I've lined up.  He like many, are mainly landscaping / patio contractors.  So probably not the best choice for getting footings pulled quickly.  

[Gus Potter]

2 hours ago, flanagaj said:

I'm going to bin off the chap I've lined up

Ok that sounds like a good move. 

 

Here is what I would do if I was you. 

 

Find the best and well repute self employed 3CX digger driver with their own machine that works local. Pay the extra. Get them round and ask them how to do it! Ask them how they want the found marked; inside, outside, centreline or all of the preceeding. 

 

Assume the weather is going to be pish and some marks get lost by accident. Set some pegs well outwith the dig so if the marks get lost you can run a string line to get you back on track. 

 

Work out what you are going to do if you hit soft spots. An experienced digger driver is going to be your best friend here. They may also say they will pitch up during the pour and can use the back actor to get the concrete in place.

 

Make sure you take plenty photographs. Be careful not to over dig. There are some horrible examples on BH where over dig happens and it just makes things ten times worse, they fill with water, hit even softer ground deeper down. 

 

Go and have a look again at what your SE is expecting in terms of ground conditions. If in doubt ask. Ask your SE if they can be on the end of the phone or just come to site if you get stuck. Yes, I know you probably don't want to pay for an SE visit but at the end of the day it can save you a pile of worry and cash. 

 

You only get one real chance of making a good job of this so don't take daft risks. Take time placing any reinforcement mesh.. many ground workers just fling it in.. and you pay for it.. but it is worse than useless if not properly placed. 

 

 

 

 

 

 

 

 

[Nickfromwales]

1 hour ago, Gus Potter said:

You only get one real chance of making a good job of this so don't take daft risks

Red flags galore......good advice!

[Oz07]

Do you need se now for standard strip footings? Back in the day just used to be able to dig and refer to a tree table if needed. I have heard nowadays bco want things designed?

[saveasteading]

55 minutes ago, Oz07 said:

nowadays bco want things designed?

Digging a hole, pressing the ground with a thumb and referring to a tree table IS design.

 

Btw you have 80m of footing there. So digging 100mm too deep and 100mm  too wide will cost you about 8m3 of concrete and 8m3 of muck-away. (£1400?)

An SE and skilled builder can save money from the start.

[Russell griffiths]

What I would do now. 
look for an experienced owner operator who has his own 5 tonne smallest 8 tonne nicer digger, he will have his own transportation or know a company that brings his machine to site. 
he will probably have a mate who helps. 
 

you can find these on a Facebook site called 8 tonne and below. 
 

you will need a surveyor or you ( surveyor best ) to set everything out all pegs in the ground ready. 
you need a 3 tonne dumper minimum. 
you need 2-3 muck away companies in your phone who you have chatted to. 
you need building control to have been notified and ready to inspect as soon as you start. 
you need to have priced concrete and have it all ready just waiting on a phone call

you need a concrete line pump for the pour day.