# Water Proofing an exterior stair case



## Trafly (Jun 19, 2014)

New here, so I hope not to offend on my first post.
I'm having to replace an exterior four tread stair case that has rotted out. The owner, and myself, are concerned about water issues, so I was wondering if it permissible to put the treads at a very slight slope to make sure the water will drain (not pool against the risers or the house). Does anyone do this? The stair case butts up against the house, which is shingle. The reason for the concern is that the treads will be made up of 1" VG DF 13" deep 8ft. wide. 
Also, in all my research, I always see the the riser is usually installed behind the tread rather than on top of the tread. Is there a reason for not doing it the other way? 
I'm certainly planning on sealing the cut surfaces of the stringers and the back and undersides of the treads and risers. (this will be a closed style design) I'm using cleats so I can screw all the treads and risers from below and behind.
Are there any other tricks that you all might recommend to ensure longevity?
Thanks in advance.


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## jb4211 (Jul 13, 2010)

Where is this being installed: state, country, etc.

If rot from water it's the main concern and its only four steps why not consider another material: concrete, pavers, etc.?

I've never sloped my stairs to enable better water run-off.


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## hdavis (Feb 14, 2012)

Sloping is common around here. You cannot, however, get a slope on the top part of the stairs if it's coming off a deck that isn't sloped. Check your local codes for how much (if any) you're allowed. Something like 1 degree in any direction. If you're coming off a level deck, you're going to wind up having to build it with a slight twist in it.

If you have room, you can keep the water off the house with housed stringers.


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## Tom Struble (Mar 2, 2007)

i don't get it,your building the stair over the top of the siding?how is the ledger flashed?


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## Dave in Pa (Oct 10, 2009)

Tom Struble said:


> i don't get it,your building the stair over the top of the siding?how is the ledger flashed?


Did I miss something? siding?


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## Tom Struble (Mar 2, 2007)

i don't know


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## Dave in Pa (Oct 10, 2009)

Upon further review here! I see that you are in CA, so the issue of snow and ice might not be a factor! I would NOT sloop them in a cold area, for they might and will get "slicker than snake chit" As per code?? As for the riser behind the tread, I do it, and think that the fasteners/ nails, or screws through the vertical riser, into the treads, makes for a much more stronger finished job, with out sag and call back issues!


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## Trafly (Jun 19, 2014)

*Re: Water proofing an exterior stair case.*

All,
Thanks for your input and questions. First, yes I'm the SF Bay area. The steps are the entrance way to and old Craftsman, which lead up to (or down from) the front porch/veranda. The whole thing is a bit of a mess. as I was hired to just replace the hand rail and the Newell post, which is a built up box. When I took off the railing and ballusters, I discovered that the treads below were all rotted. I also discovered that the stairs had been encased under fiberglass. So, right now I'm building the treads, and when I'm ready, I'll go rip out the existing treads/risers and bad stringers. The stringer which is against the house, and the center seem to still be in good shape, so I'm hoping to be able and save them. As the span is 8ft, I'm planning on copying the stringers and add two more. The one stringer out from the house is rotted and will be replaced. As for the exact details of the connection to the house, I'm not sure as I've not taken this apart. I have been underneath and poked around and it all seems solid and tight, as I don't see evidence of water between the house and the stairs
Thanks again,


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## jb4211 (Jul 13, 2010)

That downspout would be one big block of ice in the winter here in Philly


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## TBFGhost (Oct 9, 2008)

Put a very minor pitch on it and call it done. I would be surprised if most exterior stairs were perfectly level after sitting in the elements. Throw a degree or so on it to prevent pooling if your worried about it and done.


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