Open air under cantilever
#19
(06-27-2018, 01:14 PM)crokett™ Wrote: Why doesn't the plywood cover the area under the steps/doors?  Unless I'm mistaken,  I'm thinking the plywood is attached to the edges of the joists underneath the overhang to cover the insulation.   I would use PVC sheets or something that doesn't rot.     As long as the stairs and the 1x12s or whatever seal that area up, yes you need to add some sort of vents to allow airflow through it.  I don't think you need vapor barrier on the ground.

You are correct...sorry that I didn't explain that better.  The 1/4" in ply today is simply there to close up the joist bays and hold the insulation in.  Good idea on the PVC...never thought of going with plastic so it doesn't rot.  Correct that the stairs and then PT lumber (1x12s) would then close up the vertical distance from the bottom of the joists/ply to the ground itself.  

My thoughts about the vapor barrier was thinking that would leave me with no vapor barrier between the dirt ground and my subfloor.  But I could just get a roll of paper backed insulation and stable them to the joists paper-side-down.  Plastic sheet on top of that to close it off...then just the PT lumber with some louvered vents cut in to close everything off.
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#20
(06-27-2018, 01:22 PM)brnhornt Wrote: ...My thoughts about the vapor barrier was thinking that would leave me with no vapor barrier between the dirt ground and my subfloor.  But I could just get a roll of paper backed insulation and stable them to the joists paper-side-down.  Plastic sheet on top of that to close it off...then just the PT lumber with some louvered vents cut in to close everything off....

That would be double vapor barriers; something that I recommend you try to avoid. Moisture vapor will condense between them and not dry out fast enough to prevent mold. Here's what I do under additions without a full foundation (this includes both piers and frost walls). Install fiberglass batt insulation "sufficient to fill the joist space, minimum R-19" (that's code in my area). If it's kraft faced the kraft paper is on top (facing the conditioned space and in contact with the sub-floor) I use 7/16" O.S.B. painted with oil base house or deck paint before I even cut the sheets to fit. I tape all seams and edges with Zip Wall tape and staple it as well (just in case the adhesive fails in less than twenty years). I buy "miss-tints" from my local lumberyard for $5 a gallon, pour it on the sheet(s) and spread it out with a soft push broom or cheap car washing type broom/brush.

Newer Codes for decks specify that the ribbon joist should not be spaced away from the wall; however it looks like your siding and corner boards are already applied and you don't want water to get trapped between them. In this case I would use 1" lengths of PVC pipe as spacers or strip the siding and add ice/water shield and use P.T. 2 x ? between the corner boards and then double it the full width of the bay. These should be flashed before decking and sealed to the ice/water before covering with a PVC kick board. (Basically butting the corner boards on both sides.) Also aluminum and P.T. cannot touch each other. The aluminum will turn to white dust in a few years.
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#21
If I were doing it, I'd just insulate it with craft faced fiberglass insulation (Craft face towards the conditioned area) and use metal J-Chanel and a vented/perforated metal soffit to seal it all up. Vented so it can dry out if water ever gets in from above. And forget about it. No fuss, no muss and a quick installation. Tin snips and some siding/roofing nails.

Wouldn't use plywood. No reason to add new maintenance items.

Were the old steps attached on the siding?
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#22
(06-27-2018, 01:09 PM)brnhornt Wrote: Good point...I don't have anything specific to the area exactly...but this crop of an overall shot shows it:


The red circle is the area beneath the french doors in question.  The discoloration of the bottom two courses of siding under the doors are from the previous steps...so the new steps would cover entire door-wall to the same level.  The PT wood would need to be up/under the left/right sides.  Sealing the whole thing up.


i think id replace the insulation and PVC panel, have the patio ran up to the basement wall, install stairs, and call it a day. in other words,i dont see a reason why the  the cantaliever  has to be enclosed.
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#23
(06-30-2018, 06:25 AM)Snipe Hunter Wrote: If I were doing it, I'd just insulate it with craft faced fiberglass insulation (Craft face towards the conditioned area) and use metal J-Chanel and a vented/perforated metal soffit to seal it all up. Vented so it can dry out if water ever gets in from above. And forget about it. No fuss, no muss and a quick installation. Tin snips and some siding/roofing nails.

Wouldn't use plywood. No reason to add new maintenance items.

Were the old steps attached on the siding?

Pulled the plywood down carefully and it was in good shape.  Figured it's lasted 30 years and didn't want to spend any more money so I just reused it.  Other than that...your idea is pretty much what I did...cut away the old/damaged insulation and installed new faced insulation.  Put the plywood back up and secured it with a handful of screws...should be good for another 30 year.

As for the steps, yes/no...no strong bond, but it looks like there was a dab of construction adhesive on the left and right side...and then a small bead of caulk around the perimeter.
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#24
(06-30-2018, 08:26 AM)tomsteve Wrote: i think id replace the insulation and PVC panel, have the patio ran up to the basement wall, install stairs, and call it a day. in other words,i dont see a reason why the  the cantaliever  has to be enclosed.

True...it probably doesn't have to be enclosed...but it might look a little lop sided with the stairs covering the front and then the left/right being open.  I think enclosing it gives it a more "finished" appearance.
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#25
(06-29-2018, 10:31 PM)MstrCarpenter Wrote:  Also aluminum and P.T. cannot touch each other. The aluminum will turn to white dust in a few years.

Thanks for that!  I've never head that before...so I'll avoid that for sure!
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#26
In my area if you don't attach the deck to the house it does not require filing plans.  It looks to me like you could do the same.  It would require poured piers near the house, but possibly not elsewhere.
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