Hello all,

I am about to replace the floor board near the house on my deck and was wondering what I should do about the flashing on the ledger board.

I believe it is made of aluminium and is about 13 years old. Its looks a little chalky and pitted in place and is brittle in some places. I don't think it has outright failed yet but I think I should definitely do something about it.
It is L-shaped (not Z-shaped). It barely covers the top of the ledger and extends up behind the siding perhaps 3-4 inches.

The new floor plank will be acq pressure treated.

Here are some options I see:
1. The simplest improvement would be to run a strip of 4-inc grace Vycor Deck protector along the top of the existing flashing -say 2 inch under the sidiing, 1.5 inch over the top of the ledger and perhaps 0.5 inch down the face of the ledger except for where the joists are.

2. Use a new piece of formed flashing. I found (z-shaped) plastic flashing in 8 foot lengths at a nearby hardware store. Could I just place this over the old flashing? This would seem better than removing the old flashing.

I may have some other options but perhaps we should address these two first.

Thanks, John

 

I would recommend you replace it with a 4x4 galv wall flashing. (L-flashing)

 

The reason you're replacing that deck board is probably because it rotted from the bottom up, mainly from water trapped between the old flashing and the underside of the board. If that is what actually happened, you can prevent it from happening again if you kerf some transverse cuts across the bottom of the new board, forming small channels for trapped water to escape through. A heavy coating of preservative in the kerfs will keep them from rotting prematurely.

 

Anchorseal 2 is a good product to brush on the end grain after you cut your boards to length, you could probably also brush it on the kerfs that Bridgeman is recommending.

 

Hi,
Thanks for the replies so far.

The floor board on top of the ledger did not rot - I took it off in the process of fixing some joists.
I have seen the tip of cutting some gaps in that floor board to allow it to drain. If I do that I will use the product I am using to treat the cut ends, which is Woodlife CopperCoat Green Wood preservative.

Right now I am trying to figure out how to flash the ledger with a product I can easily get nearby.
The plastic flashing is nice because it is inert (no dissimilar metals issues or corrosion by ACQ), but it is a little thick and might be harder to squeeze in - I might have to lift the siding/trim a little.

The galvanized flashing I see at Home Depot says not to put in direct contact with ACQ PT wood. I am not sure if it would be good to put this on top of the old aluminum, but it may be ok to do this with the plastic product.

 

Anyone else have an opinion on supplementing the old flashing vs removing it and using new flashing?

Thanks, John

 

Vycor may be a good solution, but it sure would help if you were to post a couple of pictures (not closeups) of your situation. Seeing helps to decide on advice. Thanks. http://www.doityourself.com/forum/el...your-post.html

 

Here are two photos showing the flashing.

 

In the close-up photo, it looks like the joist hanger isn't attached to the joist, but rather just the ledger board. If same is true for all of the joists ends, that deck must have a lot of "wiggle" in it when loaded.

 

Thanks for pointing that out, BridgeMan45, but its just the angle of the picture.
Unseen below the deck boards there are the 4 3" nails into the joist and then ledger. In general all the joist hangers have all the proper nails and are nice and tight.

Any opinion on how to improve the flashing before laying the last plank?

 

If that was my job I'd loose all that old wooden trim, remove the aluminum flashing (your right any metal except stainless steel or copper flashing will react with the copper treated new joist.)
Replace the wood trim with PVC lumber.

 

Hi joecaption1,

I tend to agree with you that the right thing to do would be to replace the wood trim with PVC.

However I would like to change the flashing as little as possible, since it seems to be doing the job.
I am thinking that by adding to the existing flashing there is less chance of goofing up.
What do you think of just adding plastic pre-formed flashing on top of the old aluminum? Since it is plastic it won't react with the aluminum.
I think I should still remove the trim/siding and run a strip of Deck Protector along the top edge of any new formed flashing that I add, then lap the housewrap paper down on the outside as is done currently.

 

The bottom edge of the vertical trim board shown in the closeup photo is fairly decayed.
Is there any way to just replace the bottom 6 inches of this board?
Seems like it would be hard to cut out without removing the whole board.
How would I join the new piece (wood or PVC)?

Or should I just pull the whole board and replace with new wood or PVC?
Is there any concern with the old nail holes being a path for moisture to get in? Do I need to do anything to seal them?
Should I caulk all 4 sides (with regular painters caulk) when the new piece is in?

 

I would replace the whole board. Second, replace 1' of it with a 45* angle cut at butt to drain water outside and use some biscuit joints with waterproof glue. The plastic on top of old is fine if tucked under the WRB. Vycor life in direct sunlight- 30 days.....

Gary