Best Water-resistant Shuttering Board?

[Mulberry View]

I need to reinforce some relatively large vertical details before my Nudura ICF concrete pour. What is the best structural material to use for this? Will hardwood plywood stand up to the elements for a few weeks? I'm hoping to do my pour before Christmas, but I need to allow for this possibly being up into January.

 

Some stuff I'm doing with timber, but I'd like sheet material for larger areas.

 

(This pic is a few weeks old now)

 

[jamiehamy]

it'll be absolutely fine. 18mm WBP ply, will last a LONG time as I know from our shuttering, we ended up reusing it many times for other things after. 

[Mulberry View]

  On 27/11/2023 at 11:31, jamiehamy said:

it'll be absolutely fine. 18mm WBP ply, will last a LONG time as I know from our shuttering, we ended up reusing it many times for other things after. 

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So, this stuff?

 

https://www.travisperkins.co.uk/plywood/18mm-x-2440mm-x-1220mm-structural-hardwood-plywood/p/767336

 

I get that for around £30 a sheet. Will I need to treat the edges?

[jamiehamy]

  On 27/11/2023 at 11:39, Mulberry View said:

 

So, this stuff?

 

https://www.travisperkins.co.uk/plywood/18mm-x-2440mm-x-1220mm-structural-hardwood-plywood/p/767336

 

I get that for around £30 a sheet. Will I need to treat the edges?

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That's the stuff. It's pretty 'belt and braces' tho, so I'm assuming you're going to use for things like lintels and jambs? I used it on both for our ICF build - we had a huge lintel for the garage door (4.7m) and it was shuttered with 18mm - and remained in situe until we fitted the door two years later and it was still useable for rough stuff. 

 

How are you planning propping your lintels, esp the big ones? I would be having 4 or 5 vertical 6x2s in there at least or acro props - it's some weight of concrete up there when it's not set, and you don't get a chance to 'sort' it once you spot it sagging!

 

Assuming you're going to put a lot more bracing up before pour? 

[Mulberry View]

  On 27/11/2023 at 12:25, jamiehamy said:

That's the stuff. It's pretty 'belt and braces' tho, so I'm assuming you're going to use for things like lintels and jambs? I used it on both for our ICF build - we had a huge lintel for the garage door (4.7m) and it was shuttered with 18mm - and remained in situe until we fitted the door two years later and it was still useable for rough stuff. 

 

How are you planning propping your lintels, esp the big ones? I would be having 4 or 5 vertical 6x2s in there at least or acro props - it's some weight of concrete up there when it's not set, and you don't get a chance to 'sort' it once you spot it sagging!

 

Assuming you're going to put a lot more bracing up before pour? 

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I managed to build most of the first floor, up to 10 courses in places without the Nudura props. I now have them up and in place, that photo was a while ago.

 

I have made support beams for the window openings. These are 18mm Hardwood Plywood, with 2no 4x2 Stiffeners (on end), spaced for Acrows. I have added a length of Battening Timber to each edge as I have to do some more reinforcement to the external face of each opening. Then the whole thing is wrapped in Visqueen to keep it from twisting and warping in the time leading up to the pour.

 

 

I've used Acrows where possible and timber where it isn't.

 

 

I still have to strap the sides in. If you look carefully, you'll see a 60mm slither of block over the top of the window opening which was unavoidable, so I plan to strap this in with a length of 4x1 or 6x1 screwed over the top of it and onto the battens I added to the support beam, to remove any threat of it blowing out during the pour.

 

Edited November 27, 2023 by Mulberry View

[BotusBuild]

  On 27/11/2023 at 12:36, Mulberry View said:

without the Nudura props. I know have them up and in place

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I was just going to say, GET THE NUDURA PROPS 🙂 

 

Out distributor also supplied a whole load of bracing brackets of varying types . I just added a few more bits of ply and 2x4 to brace windows and door openings (to be sure)