help with foundations

[b21playa]

Having looked around, it seems that 4 cubic meter's of concrete will cost just under £500 for readymix, or £350ish if I mix it myself.

I initially thought it would only be £250 so trying to see if there is a cheaper way to go about it.

Can anyone help to give idea's?

Trench blocks?

 

[noseall]

readymix is very economical if it can be shot straight into the trench and you have full loads.

it gets difficult once you have to move it over a distance and are seeking part loads.

we often buy bulk loads of ballast (sand 'n' gravel mixed) and mix our own concrete, as any we have left over will do the slab and fill the cavities.

we always mass fill our trench. it costs a lot more to lay block courses low down and you need a wider trench in which to work.

 

[b21playa]

readymix is very economical if it can be shot straight into the trench and you have full loads.

it gets difficult once you have to move it over a distance and are seeking part loads.

we often buy bulk loads of ballast (sand 'n' gravel mixed) and mix our own concrete, as any we have left over will do the slab and fill the cavities.

we always mass fill our trench. it costs a lot more to lay block courses low down and you need a wider trench in which to work.

How much ballast will I need for say 4 m3?

Considering the distance, either I get it pumped or mix it myself (I already have a mixer)

Also as I will only be building it single skin wall (6" concrete blocks), do I need engineering bricks up to DPC or can I use the blocks there as well?

All will be rendered so shouldnt see any blocks

Thanks

 

[staningrimsby]

we often buy bulk loads of ballast (sand 'n' gravel mixed) and mix our own concrete, as any we have left over will do the slab and fill the cavities
.

Nose just to get this right, are you supposed to fill the cavity below DPC with concrete ???

 

[theSouth]

>> Nose just to get this right, are you supposed to fill the cavity below DPC with concrete ???[/quote]

yep, with slope to outside wall. fill up to about 225mm below DPC I think

 

[b21playa]

is it okay to use blocks below DPC instead of engineering bricks, its just it will work out cheaper for me and quicker for brickie to lay

 

[noseall]

is it okay to use blocks below DPC instead of engineering bricks, its just it will work out cheaper for me and quicker for brickie to lay

yup, blocks will be ok provided they are 7n fellas or f/l rated.

lay in 3:1 mortar.

 

[b21playa]

is it okay to use blocks below DPC instead of engineering bricks, its just it will work out cheaper for me and quicker for brickie to lay

yup, blocks will be ok provided they are 7n fellas or f/l rated.

lay in 3:1 mortar.

Im sure they are are 7n rated, they are the 6inch solid concrete ones

 

[noseall]

sounds good to me.

 

[b21playa]

sounds good to me.

Cheers

will save on cost of it all, as the blocks are quicker to lay plus im getting them at 70p each hopefully. 2 rows on foundation should be 150mm above outside level for DPC

 

[b21playa]

sounds good to me.

Noseall

As you seem to have a wealth of knowledge and very kind to offer advice, is it possible to lay the 6" blocks from DPC level to the 2m height in a day for a 2 and 1 gang?

I can get the blocks moved from the front of the house into the garden so they dont need to mess about moving them.

Just trying to work it out on labour costs, some said £300 for a 2 and 1 gang a day

 

[noseall]

possibly.

time wise i'm sure they would put a big dent in the job.

it is just whether the mortar will stand it. heavier blocks will buckle.

they may be able to course-up at differing locations around the job throughout the day. this will give the opportunity for the muck to firm up a bit.

140mm blocks may respond better than say 100mm, but i guess they are hollow?

 

[b21playa]

possibly.

time wise i'm sure they would put a big dent in the job.

it is just whether the mortar will stand it. heavier blocks will buckle.

they may be able to course-up at differing locations around the job throughout the day. this will give the opportunity for the muck to firm up a bit.

140mm blocks may respond better than say 100mm, but i guess they are hollow?

Not hollow noseall, they are solid concrete ones.

 

[namsag]

4.2 metres of concrete off one of those lorries that mixes it there and then with no wastage and only charged for what you use cost me £383 two weeks ago . Had to barrow it round to back of house but 4 of us it only about 20/25 mins.
Far easier than mixing it yourself. Pump costs another £150 plus i was told

 

[b21playa]

4.2 metres of concrete off one of those lorries that mixes it there and then with no wastage and only charged for what you use cost me £383 two weeks ago . Had to barrow it round to back of house but 4 of us it only about 20/25 mins.
Far easier than mixing it yourself. Pump costs another £150 plus i was told

Thats a good price, will cost me £300 in Balast and cement, plus god knows how many hours mixing it.

How many barrow loads was 4.2m?