Cladding, shadow gaps and breathable membrane.

[ToughButterCup]

This thread is a very helpful discussion on some aspects of cladding. @Russell griffiths made the point that he wanted to avoid building an insect theme park as well as a house.

 

In that context, it was suggested by @the_r_sole that the breathable membrane be placed on top of the supporting battens, and the boards directly on the membrane. 

 

That's a very appealing idea because we want to have 10mm shadow gaps. AKA an invitation to all invertebrates and some fauna to live happily ever after installing our cladding. Come to think of it, a tribe of Great Crested Bloody Newts would have no problem in setting up home in there either.

 

So:

• membrane against the wall, battens on top then cladding  OR
• wall, then battens, then membrane, then cladding

Which?

[Gone West]

To be awkward I have a combination of your two choices.

Wall, membrane, battens, membrane, cladding. To be different I do have EWI between the battens and then counter battens before the outer membrane.

[ToughButterCup]

?

I think they could both work; but what worries me is having membrane in direct contact with the cladding. There's a high chance of the membrane keeping moisture close to or in contact with the wood.

Not good.

[jack]

19 minutes ago, AnonymousBosch said:

?

I think they could both work; but what worries me is having membrane in direct contact with the cladding. There's a high chance of the membrane keeping moisture close to or in contact with the wood.

Not good.

 

I discussed this with a few builder types I know and this was the consensus. I really disliked the idea of wet membrane against the back of the cladding.

We have 8mm gaps between our horizontal larch, with the membrane behind the battens. Only insect problem I've noticed in 4 years was a wasps' nest last year, but they got in via an unfinished opening at the bottom of the cladding, at one end of a balcony we were still working on.

[mvincentd]

Wall, membrane (uv stable if you can find some), battens, insect mesh (uv stable), cladding.

 

If you're really concerned about the mesh/cladding contact then fix it to the sides rather than the front of the battens so that its effectively stepped back.

[ToughButterCup]

29 minutes ago, mvincentd said:

[...]

fix it to the sides rather than the front of the battens so that its effectively stepped back.

 

Thanks, helpful.

About the fixing - fix the insect mesh to the sides of the battens?

I'm a Very-Slow-Bear this morning, with a 15mm shadow gap, how might that work then?

[mvincentd]

Clearly the depth at which you set the staple from the front edge of the battens will dictate a certain amount of cavity behind the cladding still, but much reduced.

I think I actually economised on staples by only fixing into the top of the battens, so the mesh then pulled round the batten and down to the next one slightly pissed off the vertical.

[Gone West]

4 hours ago, AnonymousBosch said:

?

I think they could both work; but what worries me is having membrane in direct contact with the cladding. There's a high chance of the membrane keeping moisture close to or in contact with the wood.

Not good.

Sorry, I didn't notice in your original post. I don't have a gap between cladding, mine is just T&G cedar.

[ToughButterCup]

5 hours ago, jack said:

(...) 

We have 8mm gaps between our horizontal larch, 

(...) 

@jack, any chance of a photo?

 

The reason I ask is that I don't have a clue about how big the gap should be. I'd guessed about 10 mm - busy going through cladding images looking for the shadows and trying to estimate how big the gap is ?

 

Why not 20 mm, or 6?

[jack]

I think we saw something we liked and the source mentioned an 8mm gap. Might have been something about keeping insects out too. I can't actually remember, to be honest!

 

This is it. Siberian larch, west-facing with 4 years of weathering:

 

[ToughButterCup]

Yer a star, thanks. 

Ian