Timberframe cladding - Cost of cavity barriers and insect mesh

[saveasteading]

6 minutes ago, markharro said:

pointless and just more money down the drain.  

If i am reading this correctly, you slats are entirely aesthetic, with gaps between. At some stage it becomes so open that insects are not interested. 

[AliG]

20 hours ago, markharro said:

Hi @AliG I am just at the stage now of having to check this tedious fire barrier stuff - like you it seems we are having open timber cladding and it seems totally pointless. Our vertical battens are 45mm deep and horizontals 22mm giving 67mm in total. Is that similar to you? What product did you end up using - was it the Envirograf ?

 

Also how did you deal with the Envirograf being blue I think and the Tenmat red when, you like, we are looking for something black to camouflage with our black membrane and battens etc?

 

thanks.

 

PS did you ask Building Control if you could just dispense with the stuff for the wall sections where you are using open cladding? Same with the insect mesh - both seem pointless and just more money down the drain.  

 

We used Tenmat I think as they are red.

 

Eventually after a lot of arguing about it, the architects drew up every elevation of the house with exactly where mesh, Tenmat etc went. It was too difficult to tell just from a description.

 

None of our cladding is full height, there is a band of render 500mm tall around the middle of the house, so the Tenmat was behind this. I don't think it would be noticeable behind the cladding however.

 

Re your point though, I don't think the space behind open cladding is a "cavity" as it is not sealed and thus I don't think the regs apply here. Would probably need to check with BC.

 

We used solid battens at the corners of the building as you don't need air to circulate around corners. The Tenmat is on areas where you need vertical air circulation.

 

Originally the architect wanted it all around every window opening. MBC said that people normally battened around openings. The architects didn't like this as it would prevent air circulating behind the render board above the windows. Thus we agreed to solid battens at the sides of the windows and Tenmat above.

 

There is no insect mesh at the bottom of the cladding as it is open. But if there is cladding next to renderboard, we treated the cladding area like a window and so had battens at the sides and mesh and Tenmat at the vertical junctions.

 

 

 

 

[markharro]

Thanks @AliG thats a good point about the cavity - I think I will see if I can persuade BC on that. How many mm of gap between your cladding boards do you have out of interest?

[saveasteading]

14 minutes ago, markharro said:

thats a good point about the cavity 

I agree. I typed it up yesterday and forgot to send. Basically any insects want a secure a d sheltered cavity and yours doesn't sound like one.

And fundamentally we are looking at the funneling of fire through a cavity, which you don't have. 

 

I don't think you necessarily  need cavity barriers or insect mesh.

Getting a bco to agree anything non standard re fire is tricky though.

[AliG]

3 hours ago, markharro said:

Thanks @AliG thats a good point about the cavity - I think I will see if I can persuade BC on that. How many mm of gap between your cladding boards do you have out of interest?

8mm