Veranda deck – concrete or modified wood?
Hi
I am (still) designing my place but getting close to done.
I could use some advice or suggestions for how to detail and build the front veranda “deck”. The landscaping/path to the veranda is more or less flat (constrained by the nearby driveway into the garage) so there is not much opportunity to change the grade here. Currently the design steps up one 8″ step onto the veranda (this is the preferred configuration so the veranda appears to belong to the house, not the landscaping). The interior floor is more or less at the same level. There is a basement so the foundation wall supports the floor joists and wall framing above.
1) If I go with a concrete slab I am worried about how to detail the slab/wall junction so any rain that makes it that far doesn’t get into the wall and framing. Concrete would be near zero maintenance and the fake stone imprinting is pretty good these days. However I would require a fairly extensive continuous poured footing and wall ($) to support the slab as the landscaping falls away towards one end. There is also the issue of whether or not this slab bears directly on the house foundation wall (sharing the top surface with the floor joist) or is dowelled into the side or a grade beam or what?
2) Alternatively I could go with the heat treated/modified wood decking that is supposed to last 50 years without soil contact. The deck/wall interface would be easier to detail with flashing and/or be free draining anyway. With this system it’s the “leading edge” adjacent the path that requires some thought. An 8″ step up here is fine but how do I set the deck framing that low without the framing unintentionally becoming a wooden retaining wall? Presumably a very small concrete retaining wall, flush with the finish grade would work (or a nice slab of granite….).
Anyway I am looking for some advice on which system, and how to detail it.
Thanks
John
Replies
Raise your basement foundation wall so that any wood framing is 8" above any finish grade. What you are describing seems to be a grade that is level on the garage side of the house, which would make it slightly higher than your foundation wall. That is assuming a combination of mud sill/joist and sub floor height of 12". That means your grade is 4" higher than the foundation wall top. Not good, no matter what, IMO.
Maybe I'm visualizing this wrong. Could you attach a section sketch of the foundation wall/joist/ grade without the viranda?
John
I had the same questions on what the foundation ht is. I also stay away from pouring concrete against framing/siding whenever possible. Detailing it is problematic and not worth the effort if it can be avoided.
But also would suggest re-thinking the one 8" step down.
While a series of steps at 8" isn't considered too much of a shock (depending on code ht). one step is, in my opinion.
At least try it with a concrete block-along with the wife is that is the case.
Concrete
I'm not sure why it would tie into the structure of the house.
If it is constructed on a good gravel base that drains well, it shouldn't require a footing. Unless you are planning a verticle structure over it.
The retaining wall is probably best done in concrete.
Sorry I can't be more specific, but the details you are giving, don't form a very clear picture in my mind.
still wondering about wood
All
pdf's attached (hopefully) showing section through the veranda and relative elevations of interior, veranda, and path leading up to it.
I've also attached a portion of the main floor plan showing the proximity of the garage which limits grade changes on the path.
I won't have any of the house framing within 8" of ground.
I am thinking i can save myself a big chunk of change if i could go to a wooden solution. a friend has that thick coating that looks like stone on their PLYWOOD deck (making it water tight and non slippery). I know my way around wood framing but the concrete option is a bit of a mystery to me.
If concrete would mono-casting the slabe with a tiny curb (2" x 2" ?) along the house siding edge be constructable? Likely done before the house framing. If so this could be positioned directly under the 2" XPS and be completely non intrusive.
Hopefully the attached pdf's illustrate the situation.
(If i raise the ground floor it changes the basement height which in turn reduces my FAR exemption. (We get to exclude basement floor area where it is at least 50% below grade and i am pretty close on maxing out here.))
Thanks
John