MBC foundation question. Do I need that much Type 1?

[rufusmacdoofus]

Hi everyone

 

We are booked to have MBC do our insulated foundation on the 11th May. We need to install 500mm of Type 1 in the foundation and for 1 metre around the building. Our building measures 23.625 metres x 7.5 metres. It is a rectangle with no bits sticking out!  I have been told by MBC that we need  to order 240 tonnes of type 1. The best price I have for this is £6228 plus VAT                 .

 

Questions

1)I am assuming once compacted that no matter how well it is done this cannot be an exact science because there will be minuscule air gaps?

2) Should we do it in layers and how many layers?

3) Should we under order in case we end up having too much and risk not getting as good a price?

 

The cost of this is far in excess of what I had in my budget. My fault. I am sure at some point I was told Type 1 was 'cheap' so I popped in a PC sum.

 

Any help much appreciated, as always.

[epsilonGreedy]

I have discovered that it is better to source from a quarry that produces what you need otherwise you will pay another quarry to be a middleman. Near me I get best price for sand from the quarry that digs sand out of its own quarry and a bit further away another quarry produces limestone and hence offers a much better price on limestone.

 

Is the 1m perimeter just a working base or is it an important element of an insulated slab? I ask because 500mm is deep for just ground stabilization.

 

Could any surplus be used for your driveway base? Note there might be a SUDS drainage requirement that would rule MOT1 out.

[Russell griffiths]

Has type 1 been specified by the structural engineer, why not ask if there is a different type of stone that will do the same job

i believe each site has different requirements for what goes under the raft. 

 

Are mbc not installing this before the slab?

have they not given you a specification as to compaction quality 

 

if if I was putting a slab on ground prepared by another person I would be very specific as to how I wanted it. 

 

If you do end up doing it the stone should be compacted in layers, normally something like 100-150mm at a time and I would use the biggest vibratory roller I could get on site. 

[Bitpipe]

I recall that others used reclaimed, cleaned railway ballast if that is cheaper.

 

On our build, SE specced that Type 1 needed to be compacted in 150mm layers - in the end we had a single 150mm layer of type 1 at the bottom of our basement excavation (was poor quality crush with lots of visible cr@p like taps, plumbing, wiring & timber but only discovered that when it was placed and compacted).

 

We ended up using large clean stone to backfill the basement as it didn't need compaction although the contractor obviously skimped on one area (the one week I was away from site and didn't see it go in) and used excavated spoil as it sank quite dramatically, probably 50cm over a 3m depth.

 

So compaction is quite important!

 

[Jeremy Harris]

We used Type 3 (very like small railway ballast) and compacted it in 100mm layers.  Compacting in layers is important, as it's hard to compact anything thicker than about 150mm easily.

[MikeGrahamT21]

They don't deliver to your area, but just to give you an idea of price. I used this stuff under a block paved driveway, seemed good quality. They bought from a local quarry, so I suspect they add something on, but a lot cheaper than what you have got it at.

 

https://www.ebay.co.uk/itm/MOT-Type-1-Roadstone-Hardcore-east-Midlands-Area-20-Tonne-Bulk-Load/252167572303?hash=item3ab65bcb4f:g:NVoAAOxyM1VRY8ew

 

Comes in just shy of £6k inc VAT and delivery for 240tonne

[LA3222]

I used 2" fine for 500mm and then finished off with 1" fine for final 100mm.  Your price for hardcore seems very high - I paid £14/T plus VAT.  Yours works out around nearly double that.

[Carrerahill]

1 hour ago, rufusmacdoofus said:

Hi everyone

 

We are booked to have MBC do our insulated foundation on the 11th May. We need to install 500mm of Type 1 in the foundation and for 1 metre around the building. Our building measures 23.625 metres x 7.5 metres. It is a rectangle with no bits sticking out!  I have been told by MBC that we need  to order 240 tonnes of type 1. The best price I have for this is £6228 plus VAT                 .

 

Questions

1)I am assuming once compacted that no matter how well it is done this cannot be an exact science because there will be minuscule air gaps?

2) Should we do it in layers and how many layers?

3) Should we under order in case we end up having too much and risk not getting as good a price?

 

The cost of this is far in excess of what I had in my budget. My fault. I am sure at some point I was told Type 1 was 'cheap' so I popped in a PC sum.

 

Any help much appreciated, as always.

Should cost about £10-12 a tonne from a quarry. I got a quote from Tarmac of £12 a ton delivered in an 8 wheel tipper so a full wagon load will be about £450 delivered. You would be paying £31.14 a tonne at that price! Even dropped loose in 2 tonne loads from my local merchant it is only £21.00 a tonne.

 

Other options are 6F2 of which we got a lorry load of too.

 

A quick search just to see what is out there: https://www.littlerbulkhaulage.co.uk/shopprices/prod_1872758-Mot-Type-1-SubBase.html?gclid=Cj0KCQjwhZr1BRCLARIsALjRVQM6s6R2Aqomf641FSoqdIYC6c6Yxn6OZCHonvbK-0W8irIgzPMvDVgaAilwEALw_wcB

 

 

 

 

 

Edited April 27, 2020 by Carrerahill

[rufusmacdoofus]

15 minutes ago, LA3222 said:

I used 2" fine for 500mm and then finished off with 1" fine for final 100mm.  Your price for hardcore seems very high - I paid £14/T plus VAT.  Yours works out around nearly double that.

That was the cheapest from Mainland. Day was £30 per tonne, Hanson £32. local supplier £35!!!

 

I need to try some quarries.

[PeterW]

@rufusmacdoofus give your builders merchant a call and ask for bulk road stone. It should be £12-14 per tonne, you are being quoted by bulk bag looking at those prices 

 

I’ve done a quick calculation and it is around 120 cubic metres. That is near enough 250 tonne delivered bulk and compacted at 150mm layers. 
 

To do that I would get it in 20 tonne loads, a 5T excavator and a 3T Bomag roller. You will need to get 4 loads per day over 3 days, and spread and level as you go, assuming you can tip at all edges to the site. 
 

 

 

 

 

[HerbJ]

 

18 hours ago, Bitpipe said:

I recall that others used reclaimed, cleaned railway ballast if that is cheaper.

 Yes, that what we used.

The depth of our this material was deeper for our design 850mm for the front third, then 600mm for the middle third then 450mm for the rear third. our SE specced this because of two oak trees on the front boundary.  Somewhere, I have the number of truck loads of railway ballast delivered to site, but I can't ;lay my hands on it. 

The ballast was installed pretty much as proposed by @PeterW

17 hours ago, PeterW said:

To do that I would get it in 20 tonne loads, a 5T excavator and a 3T Bomag roller. You will need to get 4 loads per day over 3 days, and spread and level as you go, assuming you can tip at all edges to the site. 

 

Some photos

 

 

 

 

Edited April 28, 2020 by HerbJ

[HerbJ]

17 hours ago, HerbJ said:

Somewhere, I have the number of truck loads of railway ballast delivered to site, but I can't ;lay my hands on it. 

I had 16 loads, each 20 tonnes, of railway ballast

[rufusmacdoofus]

18 hours ago, PeterW said:

@rufusmacdoofus give your builders merchant a call and ask for bulk road stone. It should be £12-14 per tonne, you are being quoted by bulk bag looking at those prices 

 

I’ve done a quick calculation and it is around 120 cubic metres. That is near enough 250 tonne delivered bulk and compacted at 150mm layers. 
 

To do that I would get it in 20 tonne loads, a 5T excavator and a 3T Bomag roller. You will need to get 4 loads per day over 3 days, and spread and level as you go, assuming you can tip at all edges to the site. 
 

 

 

 

 

Hi Peter

 

It was not bulk bags sadly. The quote was for 240 tonnes direct from all of those wholesalers. I have not found anywhere that can get close to the prices you paid. I would pay someone commission if they could fine those prices as I just can't. No quarries near me - we are in West Sussex. Could you tell me where you got yours from? I am going to speak to the foundation designer at MBC and see is we can substitute for anything else. 

[Russell griffiths]

Robins quarry 

[rufusmacdoofus]

10 minutes ago, Russell griffiths said:

Robins quarry 

Just spoken to Paul there. Their type 1 is £32 per tonne!

 

[Russell griffiths]

31 minutes ago, rufusmacdoofus said:

Just spoken to Paul there. Their type 1 is £32 per tonne!

 

Did you ask for 

mot type 1 or 

crushed concrete type1

 

i would get a price and spec for everything available from anywhere, then contact the structural engineer and ask what is and what isn’t appropriate. 

[Russell griffiths]

Have you looked at crushed limestone, a few quarries around by you do limestone 

again you need to check with structural engineer. 

[rufusmacdoofus]

9 minutes ago, Russell griffiths said:

Have you looked at crushed limestone, a few quarries around by you do limestone 

again you need to check with structural engineer. 

Have sent email to MBC and they are checking with engineer. They think it needs to be MOT type 1 and we can't use recycled material so that is why it is so much more expensive. I feel very stupid because this has blown the foundations budget and we haven't even started. The point of going with MBC was the fixed price. I was working on using recycled prices.

 

If any knows any quarries near us I would be very grateful. I have only found Robins so far.

[Russell griffiths]

Day aggregates

[Jeremy Harris]

Our Type 3 sub-base is crushed limestone.  Not sure where it came from, but it was slightly more expensive than Type 1, and I had to hunt around to get it at a decent price.

[Onoff]

A few Cemex Group quarries around Sussex:

 

https://www.cemex.co.uk/find-your-location.aspx

[rufusmacdoofus]

Already checked

 

Cemex £27, 

Day £28.50

 

Best so far is Mainland. Just re checking. Thanks everyone for your help. You live and learn.

[Dan F]

On 27/04/2020 at 15:37, rufusmacdoofus said:

We need to install 500mm of Type 1 in the foundation

 

Is this due to soil conditions?  That's 1150mm below slab from my calculations, which seems a lot!   (MBC standard detail depth is 650mm including 150mm hardcode)

[rufusmacdoofus]

We had a soil survey and the spec has been provided by the MBC engineer so I can only assume so. 

[Oz07]

Would it be more cost effective to change to a bigger stone for 350mm ish or so with 150mm type 1 topping?

Would the coverage per tonne increase so much that it is worth doing?

As mentioned above I've used 6f2 before with type 1 topping under a road but with you needing virgin material 2"/3" clean could substitute the 6f2