Hello, 

Thanks to all of you who posted your solutions and fixes to improperly installed Hardie too close to the roof line. Unfortunately I am a victim of this process and I was fortune to encounter Mike Guertin’s article in Issue 257 Feb/March 2016 to that created a solution for a repair. Using a skill saw I ripped 5” of the Hardie being careful not to cut the house wrap (although I unavoidably did in some areas). 

I did this in preparation for a new standing seam metal roof which has since been installed and flashed. The contractor flashed this gap in the siding and up the wall about 7”. I also had the constructor bend cap ‘z’ flashing to the specs from another article I read in fine homebuilding. ( 3 inches verticle x 1 inch horizontal bent down at 15• x 1/2 inch verticle x 1/4 inch flared out) 

This cap flashing will go under the cut (and painted) hardie leaving 1/4” gap as recommended by the fine homebuilding article and manufacturer. The flashing will also go in front of the roof flashing and sit 1” higher when mounted. It will also ‘sit’ on a 5/4 x 4 1/2” length of PVC to be used as a trim board. 

My question is this: how do I install this cap ‘z’ flashing behind the already installed hardie plank? I have tried to pull away some boards for extra clearance but it’s really hard to get a staple or nail gun underneath for a clean shot and flush faster application? Also, how will I cut and slide the cap flashing underneath the housewrap since I’m limited on how far I can pull the hardie away from the wall? I have heard that using caulking as a glue is a bad idea since it will hold water behind the flashing. I wasn’t sure what Mike’s Guertin’s intent was for this fix and would love some advice as to how to affix this cap flashing?

Once I figure out how to install this cap flashing (don’t forgot it’s also butting up against the roof flashing going up the wall), I was thinking about installing the PVC with cortex ‘plug type’ fasteners. 

Any insight or details you could provide on this installation would be much appreciated!

I just wanted to thank this community for all of your posts and forum info. It’s helped me out of so many tight spots!

Update: 08/28/2024 – Unfortunately, I’m still stumped as to how I will ‘slip’ the new flashing under the hardie planks that I have cut (6” from roof edge to remove rotten section) and secure it without breaking the planks? Also unsure how to seal the flashing edge with Tyvek tape after I tuck this under the Hardie plank since it’s 3 inches under the board. May also run into issue with nails holding hardie during the tucking process. I can also replace planks along flat sections of roof but what about ridges? Any help would be much appreciated! Thanks everyone!

Much Obliged,

Chris K – Valparaiso, IN