# How to flash/prep for siding around concrete porch poured over wood siding?



## Dixon12 (May 3, 2016)

I'm doing siding in sections and about to get to where previous owners poured about a foot thick concrete porch right over wood siding. How would I flash/prep around that? I'll be tearing out the wood siding and gonna put sheathing and wrap around it, but obviously can't do anything about anything behind the porch slab.


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## Bondo (Dec 8, 2007)

> previous owners poured about a foot thick concrete porch right over wood siding. How would I flash/prep around that? I'll be tearing out the wood siding


Ayuh,... Is the concrete properly pitched to move any water away from the sidin',..??
If so,...
I'd probably slide the flashin' in, 'n caulk along the seam with a high quality caulkin',....


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## kwikfishron (Mar 11, 2010)

I use a Z flashing there bent at the angle of the slope of the slab. I cut a groove into the slab to accept the down bend of the flashing. I also run a generous bead of a polyurethane caulk (like Vulkem or Quad) on the concrete and seat the flashing onto that.

Cutting the groove into the slab is the critical step that shouldn't be skipped.


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## RRH (Nov 24, 2016)

kwikfishron said:


> I use a Z flashing there bent at the angle of the slope of the slab. I cut a groove into the slab to accept the down bend of the flashing. I also run a generous bead of a polyurethane caulk (like Vulkem or Quad) on the concrete and seat the flashing onto that.
> 
> Cutting the groove into the slab is the critical step that shouldn't be skipped.


I was going to say the same thing. It is the only sure way. And not as hard as it seems. May have to bend your own flashing.


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## Dixon12 (May 3, 2016)

The concrete is pitched. 

How would I cut that grove, and how deep should it go? Also, is it really necessary, since it's under a roof, except for that corner in the first picture. It runs about 20-25 ft, so any cutting wouldn't be that easy. And would I need to seal the concrete after cutting that groove? Any suggestions on how to flash/prep that inner corner in the first pic? Set some sort of kickout flashing on polyurethane caulk or is there more to it than that?


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