ledger flashing

[vin225]

can copper flashing be substituted with a piece of ice and water shield under a CCA treated ledger for deck construction? I seem to think it would perform better than anything else, but I can't seem to find any limitations on product websites. Are any flexible flashings approved to contact the new treated lumber?

[Lavrans]

Maybe.
Maybe.
Yes.

[Mark Parlee]

Vin

Come on in and introduce yourself

[kfc510]

"...CCA treated ledger..."

Are people still building with CCA lumber?
kevin

[AndyGump]

In my never to be humble opinion, copper is the very best material for your application.
I would love to spec copper in all the flashing details that I do but it is just too expensive for most people. Stainless is next then aluminum.
I my opinion of course.
Andy.

[Ablesupe]

I'd be very careful about using any metal against pt lumber that isn't specifically approved. I've had two instances that educated me. First was a strip mall where the Mech. Contractor supported his gas lines on the roof with Pt blocks right on the Galvalume roof. In six months the Galvalume was rusted away with bare rusted metal exposed.
The second was a playhouse I just finished for the grandkids. Put some 1/2" x 7" zinc plated bolts in angle braces (left over from a job)with the knowledge that I was going to replace them. Took them out after 3 months to replace with double dipped galvanized. The zinc coating was gone and every bolt was rusted.

[Lavrans]

Zinc is going to go away. The thicker the zinc coating the longer it will last, but it's a sacrificial coating (just like the zincs on a boat). Copper tends to be safe against PT because it's the primary metal that reacts with metals (zinc, aluminum, steel, etc.).

Shouldn't put copper on a Galvalume roof whether in sheet or dissolved into something else- Galvalume is Zinc coated aluminum. It does often make a nice battery though, especially with PT because they like to use salt in that. Mix up some salt, some water, some copper, some zinc...

Anyway- I really like Copper.
I'll use galvanized with PT, but I generally stick a layer of Peel & Stick between them. I don't worry about that as much with SS, unless it's somewhere I should.

[THWagar]

Stainless steel ledger flashing is a stock item at several yards here at $30 for a 10'er. No brainer for me but we're not next to the ocean like some folks......305 or 316...no idea.

There is one lumberyard in the St. Paul area that advertises as having a full stock of foundation grade lumber which I believe to be CCA but have never shopped there. I haven't seen any CCA lumber in 6 years.

[kfc510]

There is one lumberyard in the St. Paul area that advertises as having a full stock of foundation grade lumber which I believe to be CCA but have never shopped there. I haven't seen any CCA lumber in 6 years.

I actually just saw a truck with .60 ACZA beams roll by me on the highway yesterday, didn't know that was still available either.
kevin

[Mark Parlee]

Kevin
I can still get cca at.60 for foundation use.
Would that be what that was for.

[kfc510]

Kevin
I can still get cca at.60 for foundation use.
Would that be what that was for.

.60 is definitely ground-contact (i.e. foundation, etc.).

I just thought all the arsenic treatments were banned for residential use. (Not that I know where that semi with the ACZA was headed, it could have been going to a commercial bayside pier for all I know...)

You can get CCA for residential?
k

[vin225]

on simpson strongtie's website, they talk about using grace weather shield as a barrier between hangers and lumber. it was tested and approved even though it is exposed. by putting it onto the exterior sheathing and then installing the ledger board it is covered. it also seals around the fastening bolts.

[kfc510]

I'll use galvanized with PT, but I generally stick a layer of Peel & Stick between them.

That's from Lavrans' post #7, it's a common practice to put a layer of P&S between PT and metal.

But were you asking about that, or about simply using P&S *without* metal? I have not heard of anyone leaving the metal out, just isolating the two reactive components (PT and steel) from each other.

I can't actually see why a membrane alone wouldn't work, if done very carefully and protected from the elements. (I will often build sill pans for doors/windows out of just P&S, for instance.) But I've never seen P&S used alone for ledger flashing. I want the metal to protect the P&S and vice-versa.

I want as much redundancy at the wall/ledger intersection as possible. In fact, I have used three layers- compatible housewrap, P&S, AND metal at that critical location. The rigidity and clarity of the metal makes it very clear if you have a positive drainage plane.

kevin

[ThingOfBeauty]

We use just peel-and-stick all the time. It is not UV resistant and has to be covered, so we end up needing to use something else to cover the gaps between the decking boards at the house.
One of our yards sells a UV resistant dark gray plastic z-flashing designed for this location...when we don't bend up copper or stainless we use that.
I like the peel and stick because you can put half a roll, 18" wide piece and cover above and below the ledger, and it somewhat self-seals at the penetrations, plus it's compatible with everythign you're likely to poke through it or put against it.

I've seen aluminum corrode through in five months, so that's right out! Galvanized doesn't seem like a good idea either, but I guess in combination with peel and stick it could work fine.

[ddolman]

We can still get CCA here that is rated for PWF Foundations. It is not as comman as ACQ and you have to spec it. I prefer to use it as there is less to worry about with the fasteners and I am convinced it is a more durable product when exposed to the worst conditions. We dont use it where it will be the exposed wear surface for decks or such. Primarily for sill plates and exterior framing.