ICF on strip foundation

[deuce22]

Hi.

 

I have had the bricklayer bring the blocks out of ground and we are now a couple of courses below DPC. He is going to revert from laying flat to a cavity like you normally would with block work, leaving the cavity open 225mm. If I now start using ICF on top of this, then the cavity will just fill, when I start filling the ICF with concrete. What is the correct way to construct the block work at DPC if I will be using ICF.

 

Thanks.

[scottishjohn]

that detail should be on your drawings 

you still need a dpc  --so no  that wil need to be filled before dpc for the icf blocks to sit on

what type of floor ?

 

post up your plans ?

Edited May 2, 2020 by scottishjohn

[Russell griffiths]

Why the cavity, it’s not needed, solid block work

as John said, what is your floor?

have you not got a drawing done for building control. 

 

We have solid block work with a block n beam floor

i did mine a certain way that worked very well and is structural very good and I’m happy with it, however it was a massive amount of work and I’m not sure I would do it again. 

[deuce22]

I am having the drawings done for building control. I haven't got drawings yet as I was planning to build with concrete blocks. It is not for the main house, just the garage. I assumed the bricklayer would know, but he hasn't had experience with ICF, so he is just doing it the way he would, if he was building it in block work.

[deuce22]

I have strip foundations and I need to block it up, so I can then fill in the oversite.

[Russell griffiths]

Ok then, you don’t want a cavity, block on flat until icf. 

If the bricklayer has no experience with icf then don’t listen to him, you need to look on the drawings that are supplied by the icf company you have chosen. 

look at your chosen make of blocks and have a look on YouTube lots of icf on there, just bear in mind most of it is American and they get earthquakes and things we don’t get. 

 

You will need to look at a method to fix the icf in place to the blocks while you pour the concrete. 

[deuce22]

Thanks Russell.

 

I did mention to Jackon about drilling and chemically fixing steel rods and they said I can if I want, but there's no need to. The concrete will bond to the block in the same way cement does, I will fix rods though, just to be safe.

I did manage to speak with the architect and he also said continue with a block flat.

[Vijay]

No idea if it makes an difference to you but my SE wanted rods from the foundations to the ICF core, so might be an idea to check with them?

[scottishjohn]

6 hours ago, Vijay said:

No idea if it makes an difference to you but my SE wanted rods from the foundations to the ICF core, so might be an idea to check with them?

belt and braces --no need in uk --we don,t have earth quakes

[Vijay]

57 minutes ago, scottishjohn said:

belt and braces --no need in uk --we don,t have earth quakes

 

You're probably right. Polarwall (the ICF supplier) said I didn't need them but I guess the SE was just covering their backs. I also have to have them between each concrete pour too.

Edited May 2, 2020 by Vijay

[Conor]

Normally you start the ICF one course below DPC level on top of your footings. You'd then use water proofer in your concrete for the below ground block and first course of ICF. This acts as your dpc.

 

If your Brockie has no experience of using ICF, you're probably much better teaching yourself online and doing that part of the work. It's not at all like block laying.

 

 

 

 

[scottishjohn]

you have a wall bracing system -for when you pour?

that is not an option it is a must with poly block systems

 and as for the dpc what @Conor says  is one way --again look at your detailed plans for this detail

 It would not be my choice of how to do

it  all depends on type of floor -is it a slab or supended

 

Edited May 3, 2020 by scottishjohn

[deuce22]

On 03/05/2020 at 09:08, Conor said:

Normally you start the ICF one course below DPC level on top of your footings. You'd then use water proofer in your concrete for the below ground block and first course of ICF. This acts as your dpc.

 

If your Brockie has no experience of using ICF, you're probably much better teaching yourself online and doing that part of the work. It's not at all like block laying.

 

 

 

 

 

I wish I knew this a couple of weeks ago. The bricky has been a pain, not very helpful and really bad mouthing ICF. I can see this being more straight forward if using a raft, but more complicated with strip foundations.

I have come up to floor level with a block flat. I've been told to just lay the DPM up the inside wall and render as far down as I can, below floor level. There will be thermal bridging at that point, but it is a garage and the BCO isn't that concerned. My only concern is getting any damp. Do you think this will be good enough?

 

Thanks.

 

[Russell griffiths]

You really need to sort out your details or this could turn into a bit of a drama

if your icf is below ground level on the outside but above ffl on the inside then you will need an external waterproof layer or you will get moisture on the inside. 

 

I thought you are going to use the of walls of the garage to support the earth bank, in which case you will need to provide a method of keeping water out and the structure stood up right

 

you need some cross section drawings showing finished ground level outside as well as finished floor level inside, only then can you sort a method to prevent water penetration. 

[deuce22]

I agree that this is slightly awkward and it's due to me changing my mind on the construction method. I will make sure that I have decided on what I will be doing for the house and have all drawings done way before.

Regarding the retaining wall, I will discuss this with the SE beforehand, but have spoken with Jackon and they have suggested to use a waterproof concrete for the height that I need and then just fix DPM to the outside as well.

I don't really understand what this means "if your icf is below ground level on the outside but above ffl on the inside". Can you explain it?

 

Thanks.