How would you slope this sidewalk

[s219]

So we're finally getting around to putting in a stamped concrete sidewalk leading from our driveway to the front porch. This had previously been a gravel and flagstone walk with a french drain underneath:



This particular location is under the drip line of the roof, so I know I want to slope it away from the house and am thinking of a 1/4" per foot side slope. I'd normally think about 1/8" per foot, but the stamped concrete will have a slate tile pattern and I'm thinking more slope will be needed to promote drainage.

The existing grade slopes down towards the stairs -- about 14" over 24' -- so we'd probably want to put a channel drain right at the bottom of the stairs if we keep the current slope, or do a minor regrade to slope down away from the steps for a few feet before coming back up.

Thoughts? Suggestions? How would you do it?

 

[RNeumann]

1/4”/ft is more inline with code and best practice. If it’s sloped away from the house it shouldn’t need a trench drain at the stairs....unless I’m not seeing it right.
I’d invest in gutters along the walk and add a shovel footing or more along the left (looking at the photo) of the walkway. It looks like it fails off and you don’t want the walk undermined. I’d use say a 2x8 +/- along that side to get it 3-4” below grade.

 

[s219]

Yep, good idea, we were thinking of thickening it on that left side so that it holds in the gravel bed. Later there will be backfill and mulch against the left edge, but due to the slope I want to take extra precautions.

If you eyeball the mortar lines in the brick you can see how the sidewalk grade slopes down towards the stairs. Not really noticeable when walking, but I am sure some rainwater will go that way as the slope is greater than the side slope we'll have. The water will shed diagonally I guess, but the last few feet could run towards the stairs.

While I did put a gutter right above the stairs (copper for the look, but boy was it pricey) I don't want to put one on the eave above the sidewalk because we have exposed rafter tails as an architectural detail, and a gutter would spoil that. I'm not sure I would do exposed tails again on my next house, but for this current house they really make the look.

 

[EddieWalker]

Does it freeze there? Is ice and snow a concern?

Will you be pouring the concrete right up to the house or will there be an open space for plants?

If it was me, I would not slope it away from the house. To me, even the mildest of slopes to the side will be noticeable while walking on it. I would have a plant bed between the walkway and the house. I would use that plant bed for drainage. I would make the walkway perfectly flat side to side, and only have my slope leading up to he entrance.

 

[Tompet]

So on the right side stone bed, could you run a gravel/pipe French drain the length of the drip line from the porch towards the foreground in photo? Would there be enough slope for the perf pipe to foreground of camera view or turn under new sidewalk with piece of solid?

This would stop most water from going under your new sidewalk from roof dripline. For this type project around here I use 4" smooth bore HDP pipe in 20' lengths either solid or perf.

I agree gutters as a necessary evil sometimes and prefer to avoid them when possible/practical. Especially on your roof style.

 

[s219]

Does it freeze there? Is ice and snow a concern?

Will you be pouring the concrete right up to the house or will there be an open space for plants?

If it was me, I would not slope it away from the house. To me, even the mildest of slopes to the side will be noticeable while walking on it. I would have a plant bed between the walkway and the house. I would use that plant bed for drainage. I would make the walkway perfectly flat side to side, and only have my slope leading up to he entrance.

Yes, we get a fair amount of snow and freezing conditions here, and in fact that is one reason I wanted to get rid of the flagstone/gravel walk, as it was impossible to keep cleaned off and safe in the winter. I was always worrying somebody would fall. At least with stamped concrete I should be able to keep it cleaned off easier. I am half thinking I might run some poly pipe under the sidewalk to let me heat it in the future, but that's more of a fantasy idea that I'd probably never have time to complete. Unless there's a cheap low-tech way to heat a sidewalk I probably wouldn't want to mess with it.

If we make the sidewalk the full width of the stairs (54") there won't be much room for a bed on the right side -- 6" at most -- but your comments and Tompet's below have me thinking about that....

BTW, my driveway is sloped 1/4" per foot, and I don't notice it at all when walking on it. However, 1/4" per foot is very visible, and will look out of whack with the level stairs and the 1/8" per foot slope on the porch, so there is certainly a visual reason to avoid it if possible.

 

[s219]

So on the right side stone bed, could you run a gravel/pipe French drain the length of the drip line from the porch towards the foreground in photo? Would there be enough slope for the perf pipe to foreground of camera view or turn under new sidewalk with piece of solid?

This would stop most water from going under your new sidewalk from roof dripline. For this type project around here I use 4" smooth bore HDP pipe in 20' lengths either solid or perf.

I agree gutters as a necessary evil sometimes and prefer to avoid them when possible/practical. Especially on your roof style.

The drip line is about 16" from the wall whereas the sidewalk would be about 6" from the wall if we make it even with the stairs. My current french drain is aligned with the drip line (and sure moves a lot of water), but will be well under the new sidewalk. I could run a new french drain right up next to the foundation to catch any runoff from the roof/sidewalk that flows in that direction, or I could put a channel drain up against the foundation. I have plenty of options to run drain pipe right now.

 

[Tompet]

The drip line is about 16" from the wall whereas the sidewalk would be about 6" from the wall if we make it even with the stairs. My current french drain is aligned with the drip line (and sure moves a lot of water), but will be well under the new sidewalk. I could run a new french drain right up next to the foundation to catch any runoff from the roof/sidewalk that flows in that direction, or I could put a channel drain up against the foundation. I have plenty of options to run drain pipe right now.

I was going by the green carpet as only width considered. If you went full width of steps for entire run, I would agree with new channel up against the foundation. For an alternate to six inch width of long stone run, you could run concrete to foundation wall with an initial extra slope and then smaller slope (1/8"-1/4") across width of walk.

The problem with this would be freeze thaw cycles and ice build up, so your heated walk idea would be ideal for any layout! An electric mat in walk for occasional use may work. Or what about a full width pad or landing by steps extending out 4'-6' then narrowing to the green carpet and work into your existing drainage? That would allow aesthetics of your stone on both sides of walk leading to pad/landing.

I've seen many of your posts and am quite sure you will do a great job of function and aesthetics! Btw, what material is your siding and corner/window trim...looks great!

 

[Egon]

Consider laying an electric heat tape in the concrete pour?

Sloped sidewalks with ice on them are rather sliperly so do consider the amount of slope required.

 

[s219]

I was going by the green carpet as only width considered. If you went full width of steps for entire run, I would agree with new channel up against the foundation. For an alternate to six inch width of long stone run, you could run concrete to foundation wall with an initial extra slope and then smaller slope (1/8"-1/4") across width of walk.

The problem with this would be freeze thaw cycles and ice build up, so your heated walk idea would be ideal for any layout! An electric mat in walk for occasional use may work. Or what about a full width pad or landing by steps extending out 4'-6' then narrowing to the green carpet and work into your existing drainage? That would allow aesthetics of your stone on both sides of walk leading to pad/landing.

I've seen many of your posts and am quite sure you will do a great job of function and aesthetics! Btw, what material is your siding and corner/window trim...looks great!

Thanks! Siding is Hardie panel -- 4'x10' sheets with wood grain texture. Then the "battens" are 1/4" PVC. The corner trim and window trim are also PVC, 1" thickness.