Subscribe or Renew Membership Subscribe Renew

Cedar siding with no sheathing

rydogg117's picture

Cedar siding with no sheathing (post #215689)

Discovered this as I am completing the installation of a new 72x80" sliding patio door in the basement of our tri-level home. On the exterior, I've cut the siding around the door jam to accommodate the new door's nail fin, and it's now caulked and secured in place. However, the next step is to apply 4" wide flashing tape around the door's nail fin and sheathing/house wrap. Which requires me to cut back the cedar siding even further. 
So, I got some siding nails and began driving them into the siding (since I'd be cutting away sections that were nailed and the siding would have little to no support) when I discovered my nails weren't actually biting into anything. I pulled more of the cedar siding off and discovered just a house wrap, and then something very padded underneath (I'm thinking insulation baffles). 
I was surprised to see no sheathing but after some Google searches I discovered it's not all that uncommon... However, this is on the corner of the house and my understanding is that home corners should have sheathing per the code? Not that I have any recourse as this house was built in the late 70s. 
The problem is the siding was secured in place to the studs adjacent to the door, which is right where the flashing needs to be applied. 
I think what I'm going to have to do is pull down the cedar siding around the door, apply the flashing over the nail fin and house wrap, and then re-install the siding, nailing them back into the studs and right through the flashing tape I just applied. Seems like a lot of work not to mention I'm putting holes in the flashing tape which is probably not recommended.
Only other thing I could think of is adding an additional stud to provide support for the siding, but I think I'd have to approach that from the interior of the home, or else cut back the house wrap? If I cut into the house wrap, can I repair the holes with the same flashing tape I'm using around the perimeter of the door (3M All Weather Flashing Tape)?
It's never as easy as the instruction manual states...

ummmmm.... (post #215689, reply #1 of 9)

The only house wrap I remember from the 70's is tarpaper. The usual stuff I worked on back then would have 1/2 plywood corners with black board sheathing or foam in between.  Are you sure the "something very padded" isn't blackboard [also called insulation board]?

Board siding is supposed to be nailed to the studs even if there is plywood or osb sheathing involved. Might be your best recourse is to reside that area where you cut back the siding? I wouldn't worry about the siding nails going through the flashing tape. 

Stuff like this always looks easier when someone else is doing it or before you attempt it yourself.  Not to suggest you can't do it. 


If there is something (post #215689, reply #2 of 9)

If there is something resembling plywood sheathing around the opening, and nothing beyond, how is a flat surface attained?  Why isn't the siding bowing as it runs up onto the sheathing?

I suspect, as Oldhand suggests, that you have "Beaverboard" style sheathing over most of the wall.  This is a relatively soft fiiberboard product.  It is halfway good as a wind barrier behind board siding, and adds some insulation value, but it adds only modest structural rigidity, and won't take nails worth jacksith.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

dogg (post #215689, reply #3 of 9)

You mention door in basement, presumably a walkout basement?  With a stud wall ending at a foundation I'd guess there'd be no need for corner bracing.  If that's not the case, there could be a let in wood or metal corner bracing in there you do not see.  This was common practice in your vintage construction as well as earlier and later.  It passed code and has proven to be viable.

As to what to do now with the framing around he door.  Can't see it but with your description, all you need are nailers for the siding.  While you might have been able to add it from the outside prior to installing the door, I think now the less invasive path might just be from the interior.  You'd have to patch drywall/plaster on either side but you could insert framing alongside your existing from the inside, cut the nails loose from the siding (or pull) to allow you to slip strips of something like Vicor rather than thin flashing tape.  This self seals around you new siding nails.

Thats if I understand your situation.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


IDEA HERE, HEAR! (post #215689, reply #4 of 9) I understand correctly you have no solid material (stud) near the door, for holding the siding. The door is in place, held by nailing fins which, presumably, are nailed into rough opening studs. Tape the fins. For door trim consider using 5/4" thick x 3.5" wide trim boards. Rabbet the outside edge so that trim overlaps siding. Cut back the siding so the trim board overlaps by 3/4". Install the drip cap. Nail the trim in place. Now the trim holds the unailed ends of siding boards. Be sure to prime sides, faces and ends of trim boards prior to installation.To make a long story short, let the trim board do some of the "holding".

Mel Fros

Before you go any further you (post #215689, reply #5 of 9)

Before you go any further you need to establish whether there is any sort of sheathing behind the house wrap.  Your typical "beaver board" sheathing is brown or black and about the weight and hardness of balsa wood.  Or perhaps one might describe it as having the consistency of fruit cake (though it probably tastes better).

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Thanks all. I'm quite sure I (post #215689, reply #6 of 9)

Thanks all. I'm quite sure I don't have the fruitcake product (fiberboard) as I was literally able to push my hammer into the material and gave way much like insulation baffling, almost no resistance. 

@dogg is correct in that this is a walkout basement. I'm thinking there is probably diagonal bracing or let in bracing that I can't see.

The real mistake I made here was in (1) using the nail fins to begin with and (2) cutting back too much of the cedar siding. The door is secured through the jam with screws, so the nail fin only provides a small amount of additional waterproofing and not worth the extra work in cutting back additional siding. In fact, I might just pull the nails out of the nail fin and cut it away, providing me more surface area to apply the flashing tape.

I'm still going to need to replace the cedar siding pieces that I cut too short, but we're only talking five or six 3-foot segments. 

Sound like a reasonable plan?

Then again I'm reminded of (post #215689, reply #7 of 9)

Then again I'm reminded of the fact I heavily caulked behind the nail fin... Might be a disaster to try to remove. I guess I'll just do my best to apply flashing tape over it and then replace the siding.

Keep in mind that a half inch (post #215689, reply #8 of 9)

Keep in mind that a half inch of fruit cake would not be very strong -- you could easily push through it with your hammer.

If there is no sheathing behind the siding then you need to figure out what is holding the siding in place -- what's behind it 16 inches over where it's nailed into the adjacent stud.  If you had sheathing around the window and nowhere else then the siding would not lay flat.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Screws behind weather stripping (post #215689, reply #9 of 9)

HINT: Remove the weather seal all around the door and fasten jamb (door frame) to studs with screws. These screws will always be accessible!! Be sure to shim behind each screw. Re-install the weather stripping and your fastner screws should not be visible. I install all my exterior doors like this. Brickmolding fastening does little to SECURE an exterior door. Dont forget to long-screw through the top hinge. This prevents the door from sagging and binding over time.

Mel Fros