South coast ICF build

ICF seems to have really taken off with Buildhubbers lately. Maybe even more than timber frame.

 

Wrt the rainwater harvesting, where will the water go after the tank? With surface water you should go for 1)Soakaway 2)Surface water sewer 3) Watercourse 4)Combined sewer 5)Foul sewer. You may need to provide evidence (site plan and percolation test) to your sewage undertaker. Your attenuation tank may help but it could easily fill up.

Hopefully it will all get used for flushing toilets and running the washing machine. The rain water tank sizing calculator I used predicted a tick size of 3000ltr and we've gone for 4600 to give us additional margin.  We also have a tank gauge display in the house so can monitor the tank level.  I guess the problem is that you have to look at a worse case scenario where the house is not occupied. The site is too small to get teh required 5m separation of house and soak away, so it looks like surface water sewer is the way we will have to go if we can't get agreement to a soak away  closer to the house.

This is such an exciting part of the build process. I hope it goes well for you. I think it'll be really satisfying assembling all those blocks - it's like the biggest Lego/Ikea project ever!

 

20 minutes ago, Simon R said:

... and running the washing machine. 

 

I hope you'll be disinfecting the water before using it in this application.

I take it you have calculated your water run off from the roof, I used to have a 5000ltr tank and could fill it in one night with a good shower. 

 

Get some pics up as soon as you start

we have just put our last icf block in position, every item of clothing I own has expanding foam on it. 

Just about fed up with it now, ready for something new. 

Good luck, if your blocks are like my steel reinforcement, number 1 will be the last pallet you find. 

If you can connect to a surface water sewer and do away with the harvesting system you will save lots of money and grief. I have a friend in the water industry and it is just so much more economical and efficient to deal with industrial volumes.

 

For domestic harvesting, I would just go for water butts.

On 07/02/2019 at 16:44, jack said:

This is such an exciting part of the build process. I hope it goes well for you. I think it'll be really satisfying assembling all those blocks - it's like the biggest Lego/Ikea project ever!

 

 

I hope you'll be disinfecting the water before using it in this application.

We are going to try running it without chemicals initially. A bit of background reading on the sustainable sites suggests you can achieve this with good management of the tank. We'll give it a go and keep our fingers crossed.

On 07/02/2019 at 17:30, Russell griffiths said:

we have just put our last icf block in position, every item of clothing I own has expanding foam on it. 

Had to laugh, expanding foam is a nightmare, gets stuck to everything and comes off nothing!

The JUB system should mean we use very little foam during the block assembly as they are all pre-cut at the factory and interlock rather than having to be foam glued. How true this turn out to be we are about to find out.

8 minutes ago, Simon R said:

Had to laugh, expanding foam is a nightmare, gets stuck to everything and comes off nothing!

The JUB system should mean we use very little foam during the block assembly as they are all pre-cut at the factory and interlock rather than having to be foam glued. How true this turn out to be we are about to find out.

 

"Interlock"...no mortar or "glue"? It never dawned on me!  

 

 

On 07/02/2019 at 17:41, Mr Punter said:

If you can connect to a surface water sewer and do away with the harvesting system you will save lots of money and grief. I have a friend in the water industry and it is just so much more economical and efficient to deal with industrial volumes. 

We did look at connecting to the surface water sewer and the foul sewer. Because they are under the road we had to find contractors with the relevant licences, the costs were eye watering to say the least. We are connecting the foul sewer to an existing inspection chamber which required we put in a pumped solution, not ideal but affordable.

For surface water we had a similar problem, and as the site is small the 5M separation for a soak away was not achievable.  We've had discussions with building controls about how too handle the tank overflow and it looks as though they are prepared to accept a 3M separation  for the soak away.

4 hours ago, Simon R said:

We are going to try running it without chemicals initially. A bit of background reading on the sustainable sites suggests you can achieve this with good management of the tank. We'll give it a go and keep our fingers crossed.

 

You can also run UV sterilisation.

Be aware that UV isn't a true sterilisation method, it acts as a disinfection system but even then it only works reasonably well if the water supply to the UV unit has been filtered to < 5µ.  If the supply to the UV unit isn't filtered down to this level then UV treatment won't do much, as bugs will be shielded from UV by the fine particles that haven't been filtered out.  A 5µ filter will need pre-filters to take out the larger stuff, or else you'll be replacing filters every couple of weeks.  UV treatment also has an annual running cost of around £80 to £100, roughly 50% of that is electricity and 50% the cost of UV tube replacement.  To that you need to add the cost of the filtration system expendables, which depends a great deal on how clear the water coming in is.  Might be worth considering a backwashable filter vessel 1/3rd filled with Turbidex, as that will filter down to close to 5µ on it's own, and can be backwashed to clean the media, rather than having to replace cartridge filters.  Backwashing can be run automatically at night (our main filtration system does this, a backwash every 4 days, at around 02:00). 

 

I'd try and avoid over-complicating any rainwater harvesting system if you can, as even a basic system will require a bit of regular looking after and the simpler the system the better, IMHO.  If you can restrict rainwater use to non-critical uses, like toilet flushing (and NOT running the washing machine, they don't normally get hot enough to kill any bugs), then you can get away without much in the way of filtering or disinfection.  My experience is that any form of water treatment requires maintenance and incurs a significant running cost.

1 hour ago, JSHarris said:

  My experience is that any form of water treatment requires maintenance and incurs a significant running cost. 

Not what I wanted to hear. Only went down this route as we could not satisfy the 5m soak away regulation and connection to the surface water sewer was prohibitive. The tank we are going to be using has a filtration system built in and the water drains have a coarse scotchbrite filters. I'll put in two supplies to the washing machine so that if the water tank supply proves a problem I can switch it to  mains. All a bit of a complication I could do without especially as RWH systems are not carbon neutral.

Can you get away with a surge storage system, with a slow infiltration rate?  We have one under our drive, less than 3m from the house, that can hold a rainwater surge of nearly 4000 litres, which it then drains away via a small area of permeable soil.  Because I had to fit it under the drive (only place it could go, plus we needed a SuDS compliant solution for the permeable drive) I had to use the reinforced Aquacell crates, but if you have space under an area of the garden then the lighter weight crates would be OK.  They aren't cheap, but I got lucky and found some surplus ones for sale on eBay at around 1/10 of the cost of buying from my local BM.

Clear and precise answers from mr Harris as usual. ??

@JSHarris - have you got details of your surge system please?  

Yesterday my little Smart car nearly floated home as our drive was a little submerged.

5 minutes ago, Sue B said:

@JSHarris - have you got details of your surge system please?  

 

 

I just used Aquacell drainage crates (see here: http://aquacell.wavin.co.uk/ ).  I used 20 of the blue Aquacell Core crates, tied together with the Aquacell connector tubes and clips into a big rectangular block, with the block being wrapped in terram and buried in a big hole under the drive.  Runs of 110mm soil pipe connect from the top of this surge tank to the house and garage drain pipes.  The top of the crates was covered with compacted Type 3, so that water run-off from the drive can permeate down into them.

 

The only snag with this system is the cost of the crates, they are not cheap.  I was lucky, in that I found a load for sale on eBay, and it's worth keeping an eye on there, as when I was looking I found quite a few surplus crates being offered for sale.  Mine came from a ground works chap who had them "left over" from a motorway job (they use these for motorway soakaways).  Funny thing is the the seller's name was Dell, and he delivered them to us, for cash...

25 minutes ago, JSHarris said:

I was lucky, in that I found a load for sale on eBay...

 

@Sue Bthese are £20 each - half the price of new. 

Thanks @PeterW - 5days to watch

19 minutes ago, Sue B said:

Thanks @PeterW - 5days to watch

 

A bit nearer & cheaper?

 

https://www.gumtree.com/p/guttering-drainage/soak-away-crates-/1326705345