My brain will not engage today.

[Big Jimbo]

I have a bungalow, solid 9" brick, render, and plaster. My new extension will wrap around the rear, and one side of the existing bungalow. The new ground floor will be Block, cavity, block. There will then be an aprox 1600mm high, timber frame, sitting on top of the new, and existing walls. Then some roof trusses, (gable ends) and some dormers front and back.

The ground floor is going to be rendered, and the first floor is going to be cement board cladding.

1. My cladding will be vented, with an insect mesh at the bottom, but doe's it also need to be vented at the top ?

2. What about around any windows ? Do i need to close off the gap formed by the battens on which the cladding is hung, for fire etc .

3. Would you run strips of DPM down the battens before hanging the cladding ?

4. As the cladding is rot proof, would it not be ok to just to have the vent at the bottom edge, to allow for any condensation formed to get out ?

5. The battens would be treated, so would the DPM strips be considered over the top ?

 

Thanks for your help.

[Mr Punter]

1. My cladding will be vented, with an insect mesh at the bottom, but doe's it also need to be vented at the top ?

Yes

2. What about around any windows ? Do i need to close off the gap formed by the battens on which the cladding is hung, for fire etc .

Battens all round windows to close the cavity but leave the vertical battens for the render board short at the top and the bottom so the air can flow round the window

3. Would you run strips of DPM down the battens before hanging the cladding ?

It will not hurt.  Staple it on.

4. As the cladding is rot proof, would it not be ok to just to have the vent at the bottom edge, to allow for any condensation formed to get out ?

Top and bottom.

5. The battens would be treated, so would the DPM strips be considered over the top ?

Not that hard to do so you may as well.