Foundation Block versus standard blocks and Celcon blocks for both cavities

[LSB]

 

Right, thoughts please.

This came to light when trying to get quotes.
Total wall length of the whole build is 81 linear metres around the outside.

 

We had decided on using Durox foundation blocks (215 * 315 * 350 - 11kg) laid 350 wide for 150 insulation compared with Celcon foundation blocks (215*300*450 - 22kg) with 100 insulation based solely on the weight.
HID doesn't feel that he can manage the 22kg due to weight.
Trouble is one BM does Durox and the others only do Celcon.

Concrete - due to the location of good ground it looks like we need a boom pump, but they are very expensive.
Therefore, I did a little table and taking costing into account the cheapest option is 950mm concrete and 1 foundation block, which will get us up to 1175 giving enough leeway to be 150 over GL for DPM.

 

I then started looking at using blocks in foundation, but that is the same price by the time you put concrete in the middle of the cavity.

 

Does anyone have any experience of Durox v Celcon foundation blocks.

 

 

 

 

[saveasteading]

16 minutes ago, LSB said:

concrete in the middle of the cavity

Why do you need a cavity in the foundation? 

My default is concrete bed then 2 normal blocks. The 2 beds gives more chance to get the lebeks right.

 

[LSB]

15 minutes ago, saveasteading said:

Why do you need a cavity in the foundation? 

My default is concrete bed then 2 normal blocks. The 2 beds gives more chance to get the lebeks right.

 

I haven't explained myself, we don't want a cavity in the foundation.

We are filling the 1m trench up to 950mm with concrete, then we are planning on 1 foundation block, the issue we have is the different BM's offer different foundation blocks.

We weren't keen on using 2 blocks because the cavity between them under the DPM has to be filled with concrete which mean another readymix delivery, with the expensive pump due to the distance from hard standing.

Or are you suggesting something else and I haven't understood (quite possible)

 

[MikeGrahamT21]

I used the celcon trench blocks years ago, heavy buggers they were, but yeah did the job just fine.

 

how about thermalite, tongue and groove with handles? I would use them if I ever needed trench blocks again https://www.ebay.co.uk/itm/185483333075?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=dk9yp24sta2&sssrc=2349624&ssuid=SHn2lQD2QEu&var=&widget_ver=artemis&media=COPY

[saveasteading]

51 minutes ago, LSB said:

something else.

Concrete footing. 2 courses 100mm block or 150.

Backfill trench to dpm level, but with stone, barrowed presumably. Then dpm, hardcore,  pir, turned up the block face, concrete slab.

Oops my comment went into the quote box and is etaying there. Also, a concrete pump doesn't have to be a boom, if you can get round the obstructing  building. Or bring in 4 barrowers for the occasion.

[LSB]

10 minutes ago, saveasteading said:

Oops my comment went into the quote box and is etaying there. Also, a concrete pump doesn't have to be a boom, if you can get round the obstructing  building. Or bring in 4 barrowers for the occasion.

the problem isn't access it's the ground, as in a field which I'm concerned will be too soft for a concrete lorry

The field went right up to the barn and some will become our garden.

1.5 ton digger slides around so hate to think what mess concrete lorry will get in.

Also supplier said that with boom we need space for 2 lorries 🙂

 

 

 

 

[saveasteading]

OK, so you are being told to hire a boom pump. A hopper pump will do it.

[saveasteading]

You can also hire conveyors to shift the stone if it can't be dumpered. But a tracked excavator won't disappear and could form its own track in.

 

Any reason against a stone access, apart from cost?

[Kelvin]

Given the weight difference they must have different compressive strengths. What has been specified? 
 

We used Mannok Aircrete 7 300mm trench blocks largely because it was all I could get delivered to Scotland. They weigh 22kgs though. 
 

We used the digger bucket to transport the concrete from lorry to trench. We have reasonable access hardcore all the way in and around the site though and the digger has a lot of reach. 

Edited March 26, 2023 by Kelvin

[LSB]

9 minutes ago, saveasteading said:

You can also hire conveyors to shift the stone if it can't be dumpered. But a tracked excavator won't disappear and could form its own track in.

 

Any reason against a stone access, apart from cost?

Planning explicitly says that we can't form any sort of driveway or track.

 

[LSB]

9 minutes ago, Kelvin said:

Given the weight difference they must have a different compressive strengths. What has been specified? 
 

We used Mannok Aircrete 7 300mm trench blocks largely because it was all I could get delivered to Scotland. They weigh 22kgs though. 
 

We used the digger bucket to transport the concrete from lorry to trench. We have reasonable access hardcore all the way in and around the site though and the digger has a lot of reach. 

The dumper gets around okay, so I guess we could think about using that, when we had the extension built 20 yrs ago to this house the concrete had a chute which went about 5m, but the trench is 24m from the hard standing.
 

 

[Kelvin]

Preferable to wheelbarrows. That’s a lot of cement to wheel. 

[LSB]

6 minutes ago, Kelvin said:

Preferable to wheelbarrows. That’s a lot of cement to wheel. 

yes, 14 cubic meters

 

[saveasteading]

1 hour ago, LSB said:

we can't form any sort of driveway or track.

That probably means permanent access. But you wouldn't want to be digging it up again if it is a significant length.

[LSB]

4 minutes ago, saveasteading said:

That probably means permanent access. But you wouldn't want to be digging it up again if it is a significant length.

it's 120m from the road to the barn and from there to the far corner, going round the build is another 38m

LPA also talk are archealogical concerns if we dig up the driveway, so bit of a risk to do even temporarily.
The barn is up a hill from the road across a field so can be seen clearly, at least until the trees grow, but that will be 10 years so can't wait that long

 

Edited March 26, 2023 by LSB

[Dave Jones]

hire a 6 or 9 ton dumper for the day to move the concrete. they are peanuts a week from GAP

 

nothing stopping you putting in a temporary track either.

[saveasteading]

16 hours ago, LSB said:

archealogical concerns

This is usually mundane stuff like possible field margins or old footimgs. Laying over the area doesn't  prevent future investigation so will be ok.