ICF poll for DIY

[Russell griffiths]

3 hours ago, Adrian Walker said:

I have done research and hence my question.  I'm assuming that you did a fabric first approach, with Airtightness first followed by Insulation?  Thermal Bridging, Triple Glazing and MVHR would be similar for all the ICF systems.

If you think all these things are the same for all icf, then you need to look closer. 

Some woodcrete icf doesn’t have a continuous concrete core, so inherently not airtight. 

Some woodcrete does not have a continuous core at the corners, one I worked on you could actually see daylight through the blocks at the corners. 

Most woodcrete has a substantial water, damp bridge at the window reveals. 

All these things can be overcome but at what cost. 

If they are cheap enough to cover the extra work then that’s fine, you save it in one hand and pay for it later down the line. 

 

Hence my remarks on wanting it at half the cost of the product I used, Nudura 

 Now I’m not a Nudura rep, but I found a product that fitted what I wanted without any extra airtight layers or additional dramas. 

The only thing I don’t like is trying to get any tape to stick to it, it’s a total pain. 

[Russell griffiths]

On 24/12/2021 at 12:31, Adrian Walker said:

Remember that there are two external material building solutions to ICF - polystyrene and woodcrete, which allow for different wall finishes.

Not really following this, what wall finishes are you talking about that you can use on one system but not another. 

I cannot think of a single wall finish that cannot be used on all icf. 

[Mr Punter]

40 minutes ago, Russell griffiths said:

Not really following this, what wall finishes are you talking about that you can use on one system but not another. 

I cannot think of a single wall finish that cannot be used on all icf. 

 

I guess that with the woodcrete you can direct render or stick tiles or slips?  Polystyrene you may need to fix a carrier board or something back to the concrete core.

[Russell griffiths]

19 minutes ago, Mr Punter said:

 

I guess that with the woodcrete you can direct render or stick tiles or slips?  Polystyrene you may need to fix a carrier board or something back to the concrete core.

I think your right with the tiles or stone, I think it depends on the weight per metre, I have seen brick slips and composite tiles direct fixed. 

But they are obviously a lot lighter. 

[Nick Laslett]

My shell is complete, roof tiled, windows about to be fitted. I choose Thermohouse for my ICF solution. 
 

https://thermohouse.co.uk/technical-spec/
 

I also looked at Nudura, Amvic, Logix. 
 

The main reasons I went with Thermohouse, there system includes wall, floor and roof solutions, all in EPS. They use the Neopor graphite beads from BASF, which at the time I was specifying was not common amongst other EPS ICF providers. They use a galvanise steel web/flange instead of polypropylene. You can have supply and they will also do the build. They have a very good in house structural engineer. There website is easy to navigate and the technical manual and other available materials did a good job of covering the product and the built process. 
 

I was onsite every day and would say that you need someone with experience of an EPS ICF build. The process is simple, and easy to learn, but very different to other build methods. Pouring 2.7m high concrete walls could be quite daunting, but the Thermohouse house crew made it look like a walk in the park. 
 

The Thermohouse house floor product gives you a 100mm concrete first floor on top of 160mm EPS boards with steel joists encapsulated in the EPS. This fits with having a cast in situ concrete stairs poured at the same time as the floor. This was an important detail for me as I wanted a solid concrete staircase and this approach was very cost effective. We also put wet UFH in the first floor concrete. This might not be needed for heating, but could be used for cooling in the summer. 

[NickK]

@Nick Laslett, do you have MVHR? If so what is the total build up of first floor to allow for ducting? Thanks

 

[Nick Laslett]

On 07/02/2022 at 21:48, NickK said:

@Nick Laslett, do you have MVHR? If so what is the total build up of first floor to allow for ducting? Thanks

 

Good question. We will be having MVHR. There will be a suspended ceiling on the ground floor. For upstairs the ducts will run up through the floor, we put down small EPS blocks attached to the rebar when they did the first floor concrete pour. I have attached a picture from the manual. We are not at this stage yet. 

 

 

[NickK]

Thanks @Nick Laslett. I guess it wouldn’t be a best solution for when ridge height is restricted and you want decent ceiling height. This must 450mm total build up??? in comparison to posi joists which may be 300??

[Nick Laslett]

19 hours ago, NickK said:

Thanks @Nick Laslett. I guess it wouldn’t be a best solution for when ridge height is restricted and you want decent ceiling height. This must 450mm total build up??? in comparison to posi joists which may be 300??

The Thermohouse house ICF blocks are 250mm high. To not fight the system, we made our ground floor 2750mm, 11 blocks high. The Thermoboard used for the first floor is 160mm thick + 90mm concrete, 250mm in total. So the first floor is 3m from FFL. For the drop ceiling, I’m not sure of the building regs requirements, currently I plan to have a perimeter box section that drops 250mm to take most of the services and allow 2x90mm MVHR ducts to cross over. For the inside section of the ceiling I plan for a 150mm drop. A big enough gap for 1 duct and in ceiling speakers with fire hood. So ground floor ceiling height for most of the space would be 2600mm. In a few weeks I will be starting this process, so I might find I can gain 10mm - 25mm extra height.