Gavin’s isoquick foundation on clay soil

[gavztheouch]

Just had my first quote back to pour the concrete about 32m^2

 

 To be pumped in and power floated after for a finished floor. The finishing makes this a harder job.

 

first quote is £16,000 including the concrete.

 

I will be doing all the foundation work apart from the pouring the concrete. Seems to me the material and pump will be £6,000 so £10,000 for labour/management.

 

 This is worryingly high!

 

I hope I can find some middle ground with the prices.

[gavztheouch]

I used my theodolite’s optical plumb to sight over my corner markers and help get my strings in position. 3D printed some adjustable string holders to move the strings into position easily. Now I’ve transferred the points to strings it’s time to strip the top soil and add the type 3.

 

[saveasteading]

On 02/04/2024 at 14:19, gavztheouch said:

This is worryingly high!

That sounds wrong.

Pump about £500 last I looked. More if its a lorry and boom one....but do you need that?

Concrete you can work out at say £110/m3

 

Labour could reach £250 day if they are skilled .

tamps and power floats Maybe approaching £1,000 incl transport.

plus someone managing.

 

is there  reinforcement included? shuttering? 

[gavztheouch]

3 minutes ago, saveasteading said:

That sounds wrong.

Pump about £500 last I looked. More if its a lorry and boom one....but do you need that?

Concrete you can work out at say £110/m3

 

Labour could reach £250 day if they are skilled .

tamps and power floats Maybe approaching £1,000 incl transport.

plus someone managing.

 

is there  reinforcement included? shuttering? 

I’m doing everything else, shuttering, reinforcement, etc. They just pay for concrete and Labour to pour and float the finish.

[Alexphd1]

When we poured our insulated slab it was 50/50. If £5k of concrete then it was £5k for labour. How much m3 do you need? We done all the insulated slab wrk Inc rebar ufh etc.  Approx 6 or 7 guys turned up at 7am with there own concrete boom.  Concrete turned up at 8am and 3 guys stayed on site for 8 hours until they floated  everything with one of those sit on machines.

 

[saveasteading]

1 hour ago, gavztheouch said:

They just pay for concrete and Labour to pour and float the finish.

It is highly skilled BUT. 32m2 (squared?) like 6m x 5.4m?

how thick? 

or 32m3? the concrete would cost £4k.  and £16k is still too much.

tell us more and I can work out a fair price.

I have NOT read the previous pages for context.

[kandgmitchell]

We paid £138/m3 for 27m3 of C35 concrete (plus vat which we'll get back) so about £3K and £700 for a line pump plus two operatives for a day.

[DreamingTheBuild]

I think he might mean a 320m2 slab.

 

Don't know if this is any help but the couple I follow on YT were quoted circa £20K for a 380m2 slab for a polished floor, concrete was around £9K. This was just for the pour and float.

 

In Gloustershire.

[saveasteading]

On 09/04/2024 at 11:24, kandgmitchell said:

plus two operatives for a day.

How was it levelled,? Happy with the result?

[gavztheouch]

Just had another quote back, this time it’s £9800 which is more inline with everyone else’s. 50% concrete/50% labour.

 

@DreamingTheBuild do you have a link for the YT channel that sounds interesting

[SteamyTea]

On 18/10/2023 at 09:32, Gone West said:

We had the first Isoquick system installed in the UK in 2010

I forget what a trailblazer you where with your Kent build.

 

Now you have to put up with stone age building practices.

[Adrian Walker]

On 02/04/2024 at 14:19, gavztheouch said:

Just had my first quote back to pour the concrete about 32m^2

 

 To be pumped in and power floated after for a finished floor. 

have you thought of using self levelling concrete. CEMEX have Evoloution which is very good and need minimal work after the pour. 

[gavztheouch]

9 hours ago, Adrian Walker said:

have you thought of using self levelling concrete. CEMEX have Evoloution which is very good and need minimal work after the pour. 

Thanks I’ll look into this.

[kandgmitchell]

On 13/04/2024 at 07:33, saveasteading said:

How was it levelled,? Happy with the result?

Well the perimeter was set by the vertical edge insulation. My ground workers used a laser level with a square of ply attached to their staff which they used to keep checking the concrete surface level, a little crude but it worked. The two pumping guys handled all that side of things so we could concentrate on the spreading, compacting and levelling. Yes pleased with the end result - probably no more than 10mm out of level looking at the subsequent rainwater on the surface.

 

We now have the attached sitting on it - that's four days work for six men and a crane.

[saveasteading]

14 minutes ago, kandgmitchell said:

a laser level with a square of ply attached to their staff

That  can go wrong so it sounds a if they handled it well. I always dreaded puddles because the client thinks there is a problem. 5mm still makes a puddle.

It's good for the concrete though.

I'm surprised how approximate lasers are. They're no more accurate than 20 years ago. 0.5mm per m sounds little but over 20m it's, gulp, 10mm.*

If a level is 'out', it is always the same way and doesn't average out..

And more concerning is that builders all think 1. they are expert, 2, the machines are accurate.

 

* ask about equal back and fore sights.

[kandgmitchell]

I agree, I realised my groundworkers weren't as experienced in the reinforced raft field as they claimed but they worked hard, listened to my concerns when required and more importantly acted on them. A clear understanding of the process was key but by god was I relieved when it all worked out right in the end! 

[saveasteading]

18 minutes ago, kandgmitchell said:

worked out right in the end! 

pouring a slab in open conditions is a worry. wind as well as rain, then the dogs , cats and seagulls all descend to leave their marks overnight.

[kandgmitchell]

Yup, kept the cats in deliberately just to avoid the inevitable...............

[gavztheouch]

 

stripped the soil off today. We are only going down 200mm to try and stay in the stiff clay near the surface. 

[saveasteading]

2 hours ago, gavztheouch said:

stripped the soil off today.

That's very neat. 

[George]

8 hours ago, gavztheouch said:

 

stripped the soil off today. We are only going down 200mm to try and stay in the stiff clay near the surface. 

I haven't really paid much attention to this thread but this jumped out at me. The minimum formation depth for any foundation is 450mm to get below the frost depth. Are you going to insulate the surrounded ground as well as raising the level (this is commonly done in America but not so much here)?

[gavztheouch]

1 hour ago, George said:

I haven't really paid much attention to this thread but this jumped out at me. The minimum formation depth for any foundation is 450mm to get below the frost depth. Are you going to insulate the surrounded ground as well as raising the level (this is commonly done in America but not so much here)?

Yes raising the surrounding ground by something like 300mm. It’s going to give some more protection against flooding as well sitting a bit higher. We’ll need to work hard to blend the extra height into the surrounding garden.

[saveasteading]

48 minutes ago, gavztheouch said:

some more protection against flooding as well sitting a bit higher

Yes I like to stay high for these reasons.

[SteamyTea]

25 minutes ago, saveasteading said:

I like to stay high for these reasons

With booze you loose, with dope you hope

[gavztheouch]

Mistakingly I have lay down about 100mm of type 3 in areas I can not get with vibrating roller. This is areas with drains etc. 

 

If I’m doing this by the book my plate compactor does not go deep enough as it only has say roughly 300kg/m2 I need over 1200kg/m2 to get down 100mm. I found this belle product you can rent which has a small foot print attached to the underside of a normal plate compactor which apparently generates over 1600kg/m2. If this is correct then this would work and would be piece of mind for the £50 or so rental fee. Anyone heard about this belle product https://www.altrad-belle.com/index.php?route=product/product&product_id=5575 

some more info on the compactor

 

https://static-content.cromwell.co.uk/pdfs/s/medusa_attachments/bel/bel-262-3610m dual force booklet.pdf