Battens for External Wood fibre insulation

[Jenki]

Hi all, whilst waiting for the building warrant I'm getting into details. My proposed build  will be timber frame, with an external layer of 100mm wood fibre insulation on the exterior wall. The original plan was to render this, but with documented issues, I've changed tack and will be cladding with Hardie board. 

When it comes to the installation of the Hardie board I need to be able to fix the corner trims securely,  but with 100mm wood fibre this is difficult.

I've drawn a solution and welcome comments.  (just realised my Stud layout is not correct- forgive me, but the details work)

 

main questions would be, as i've never cut wood fibre, how easy will it be to cut the rebate in the ends of the boards, I have a large table saw / circular saws etc.

Does anybody see an easier solution? 

Any problems?

TIA

A thought I've just had as typing this, as the frame will be made on site, is to change 1 of the corner studs to 10x2, thus removing the 4x2?  need to draw this might need some really long screws.

 

 

[redtop]

Our house has 140mm wood fibre and then battons, counter battons and wood cladding. Oh and a vapour layer on top of the wood fibre. Anywhoo I fitted all the wood fibre myself. Circular saw works but get clogged up every 2 mins so you spend longer clearing it than cutting. Hand saw works but is hard work but would be ok just for the rebates. I ended up cutting the outside facing bit with the circular saw and then finished with the hand saw. Seemed best combination. For the corners  I used really long screws but tbh if you just fasten a batton along one edge of the Hardie board and then fasten the next one to that the corner should be solid enough. Well it was for wood cladding....

[Russell griffiths]

i Would think coupled with some good grab adhesive that will work.

And change the 25x75 for 25x100 so you get a better shot at getting the screws in straight.  

[ProDave]

I used hand held circular saw.  As above it clogs up like mad.  I ended up unscrewing one side of the cover (like you do to change the blade) and leaving it off and being very careful.  I still have all my fingers. 

 

Re your corner blocks.  Do they really need to be fixed to the frame?  The panels will be secured to the nearest batten that won't be far away from the corner, so to me it seems the important thing is they are joining the corner joint together so there is no movement, so just screwing the 2 corner battens together and then screwing the panels to the corner battens and nothing is going to move.

[Jenki]

32 minutes ago, ProDave said:

 

Re your corner blocks.  Do they really need to be fixed to the frame?  The panels will be secured to the nearest batten that won't be far away from the corner, so to me it seems the important thing is they are joining the corner joint together so there is no movement, so just screwing the 2 corner battens together and then screwing the panels to the corner battens and nothing is going to move.

I've seen some corner battens that cover the end of the board( instead of being able to see the cut edge). They are 2 perpendicular slots. I'll need to get some dimensions to see how big the back flange is.

If I can screw into that then it would be considerably easier process. Like you say the next batten will only be 250 mm away.

 I will have a similar issue on the reveals.

[Russell griffiths]

I have slid a dummy batten behind my timber cladding, it’s not screwed to the frame, but it is screwed to each cladding plank, so stiffens up the ends at all the reveals. 

[redtop]

1 hour ago, Russell griffiths said:

I have slid a dummy batten behind my timber cladding, it’s not screwed to the frame, but it is screwed to each cladding plank, so stiffens up the ends at all the reveals. 

Yep what I did and does stiffen it up a lot, certainly more than enough for timber cladding