Setting out basic footings

doobin

doobin

Well-known member
What’s the correct way for the usual basic extension? String line off wall and then use this as the centre line? Or should it be offset one way more than the other?
 
Jimbo69

Jimbo69

Active member
I usually give 150mm scarcement on the outside, dig them 600 wide then with a 300mm wall you should have your 150mm scarcement on the inside as well. Does that make sense?
 
T whiting

T whiting

New member
I prefer to mark facework with the string lines then run the footing offset it saves re marking it out to set brickwork you can just put your lines back up
 
Left hooker

Left hooker

Active member
Depends if you dig to center lines or outside of bucket as to which way you measure off of string line
Personally I prefer center lines as no confusion when it comes to internal walls and external all are middle of bucket
 
T whiting

T whiting

New member
I'll go either I normally go outside as preference though I normally make a stick with three marks on it 600 long and a mark for both sides of the wall and the center
 
doobin

doobin

Well-known member
I'll go either I normally go outside as preference though I normally make a stick with three marks on it 600 long and a mark for both sides of the wall and the center
That’s a good plan. So I could run the string off the outer edge of the wall then use the stick (at the wall edge mark) to spray a line down it for bucket edge or centre.
 
Quattromike

Quattromike

Well-known member
In my experience, builders doing founds seem to please themselves what they fit and where they fit it :oops:
IMG-20190822-WA0008.jpeg

What am I supposed to do with that!
 
Left hooker

Left hooker

Active member
Was glad the survey engineer set this site out as center lines as would have been a ball ache re-marking it all
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JD450A

JD450A

Feral as Fk
To be quite honest. This topic is the exact reason we always have the builder on site when excavating footings!

too many variables, the twats will always change there mind, and even if it's right to the plans you will get the blame when they build it wrong :ROFLMAO:
 
Gunners

Gunners

Well-known member
I've done tons of foundations, some set by engineer, others I've had to do set off a hedgerow! (TiltyShaun will know my pain there especially as it was a timber frame) It doesn't matter how you do it as long as you are consistent with your method. Some tips I've learnt;
1. When doing extensions - existing houses are rarely square and if the new extension is a wrap around then this can really screw things up. Pick a side (usually the longest) and go with that, regardless if it makes it unsquare to something else.
2. If there's steel framework in the new extension, this is particularly important as you have to go with the wall thats squarest to the steel frame if that makes sense.
3. Never assume the architect has got his dimensions right - I've had to do plenty where we had to "make it fit" But always ring the architect to tell him how stupid he is so he can adjust the drawings for steelwork people etc that come behind you.
4. Builders are rough bastards and providing you dig somewhere roughly where it looks like it should be, they will be impressed that you even turned up - let alone got it in the right place. I believe the saying is "it looks alright from my house" 😆
 
V8Druid

V8Druid

do it as well as you can,but learn to do it better
In my experience, builders doing founds seem to please themselves what they fit and where they fit it :oops:
View attachment 9588
What am I supposed to do with that!
seen a few like and worse than that :ROFLMAO: put a steel frame up once .. fair size one...one end - the start was alright ... by the time we got to the other end the col.s were sat on piles of blocks 15" outside the footing/slab, on the one side :oops::( ...... fk knows who set it out ... but they were specialists apparently 🤣🤣🤣
 
B

Brendan

Active member
Not dug any for a while, depending on situation either pull a line down the side of the house and work from there or use Pythagoras and set corners.

Generally I set the actual building corners first, check measurements then offset for outside of trench either 75mm or 150mm from pins for dig line.

I only mark two edges of the trench if it's wider than bucket ie both sides 750mm if only have a 60mm bucket

If there is any intermediate walls generally mark the left hand edge of trench with |< marked although occasionally if it's only a single skin wall, will mark centre line with ¢ line mark

Everyone has their own ways but on small machines I find it easier that way
 
V8Druid

V8Druid

do it as well as you can,but learn to do it better
In my experience, builders doing founds seem to please themselves what they fit and where they fit it :oops:
View attachment 9588
What am I supposed to do with that!
seen a few like and worse than that :ROFLMAO: ..........🤣🤣🤣
these were supposed to be on the slab :unsure::oops:o_O.... had to trek to Bognor to sort these out .... bloody ground workers :ROFLMAO::ROFLMAO:
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then went on to another site where the monkey chippies had put all the beams in upside down :mad: ..... despite them all having TOP and BOTTOM written on them in bright yellow paint marker in 6" letters, to drill/broach a new set of holes in each end to pick up the 1st/2nd floor columns.
We got a lot of that ..... if they'd only had one steel erector leading the idiots .... or better still one of my guys who knew the jobs :rolleyes:
 
TiltyShaun

TiltyShaun

Well-known member
I've done tons of foundations, some set by engineer, others I've had to do set off a hedgerow! (TiltyShaun will know my pain there especially as it was a timber frame) It doesn't matter how you do it as long as you are consistent with your method. Some tips I've learnt;
1. When doing extensions - existing houses are rarely square and if the new extension is a wrap around then this can really screw things up. Pick a side (usually the longest) and go with that, regardless if it makes it unsquare to something else.
2. If there's steel framework in the new extension, this is particularly important as you have to go with the wall thats squarest to the steel frame if that makes sense.
3. Never assume the architect has got his dimensions right - I've had to do plenty where we had to "make it fit" But always ring the architect to tell him how stupid he is so he can adjust the drawings for steelwork people etc that come behind you.
4. Builders are rough bastards and providing you dig somewhere roughly where it looks like it should be, they will be impressed that you even turned up - let alone got it in the right place. I believe the saying is "it looks alright from my house" 😆
I am usually the digger driver and the Engineer! Just finished a large timber frame house foundation where the erectors said it was the best for level he has worked on and longest diagonal was 18mm long over 20m. Told him to get a new tape!!!
 
TiltyShaun

TiltyShaun

Well-known member
Don’t know what the next one will be like as my Theodolite has now died!!!
 
F

fred

Well-known member
lasers have made foundation work so much easier these days.

laser the concrete into the footings and the brickies will love you. Pythagoras everything even after marking out with the squaring laser. I use leftover bags of plaster to mark the lines on the ground as im too tight to buy spray paint.

Couple years ago now watched them put up a timber frame on the site opposite and they used plastiv packers under the frame to get the whole thing level! They used spirit levels and pegs when putting in the conc. 10x harder and slower than screwing the laser receiver to a piece of batton and putting in the conc bang on, rake and tamp as you go. bollox to all the bending down an dipping a level on top of wet conc.
 
V8Druid

V8Druid

do it as well as you can,but learn to do it better
lasers have made foundation work so much easier these days.

laser the concrete into the footings and the brickies will love you. Pythagoras everything even after marking out with the squaring laser. I use leftover bags of plaster to mark the lines on the ground as im too tight to buy spray paint.

Couple years ago now watched them put up a timber frame on the site opposite and they used plastiv packers under the frame to get the whole thing level! They used spirit levels and pegs when putting in the conc. 10x harder and slower than screwing the laser receiver to a piece of batton and putting in the conc bang on, rake and tamp as you go. bollox to all the bending down an dipping a level on top of wet conc.
totally agree ..... with the target/sensor on a batten it'd be a doddle to check every 6" if you wanted to, from a standing position. ... level some pegs first for a datum, 'praps, but then there'd be no need to find 'em after ... just listen for the tones as you work a way around (y)
 
V8Druid

V8Druid

do it as well as you can,but learn to do it better
was wondering how you were getting on only yesterday @fred .......... hows that M1520 coming along? :giggle:
 
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