How to flash penetrations in corrugated siding?
DamionL
| Posted in General Questions on
Hi all,
I need to put some penetrations in some corrugated fiber cement siding that is screwed directly to the sheathing such as a 4″ bath fan exhaust and some AC lines.
I assume the siding panels will need to be removed for this, but what is the best way to install and flash these penetrations?
I’ve seen mounting blocks used, but those seem to be used to make future siding easier, but in this case, I will need to carefully cut out the mounting block location within the siding and reinstall.
Is there a best practice way to do this?
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Replies
With all siding types, I prefer to install "light blocks" or mounting blocks--solid wood (or other exterior trim material) flashed to the WRB just like a window or door, brought proud of the face of the cladding. Then install your penetrations, wall caps etc. on that board. They can be as small as 6" square or as large as several feet in either direction.