Under deck leaking water under siding and flashing

[Cy4Patriots]

Hi All,

I recently had a company address an issue with rotting OSB board (not flashed the begin with) under my deck, they put in new OSB, flashed above the deck and below it and put new siding up with drip edges. After this hard rain today, I see once again there is water behind the siding and dripping beneath the drip edge and on the top of the concreate foundation. They are at a loss. Any handymen here?

The first close up picture below is under the drip edge laying on the foundation where water is under it.

The second picture is the drippings on the foundation. Some of this is just dripping off the metal drip edge, others its under it.

 

[CYEATHAWK]

Hi All,

I recently had a company address an issue with rotting OSB board (not flashed the begin with) under my deck, they put in new OSB, flashed above the deck and below it and put new siding up with drip edges. After this hard rain today, I see once again there is water behind the siding and dripping beneath the drip edge and on the top of the concreate foundation. They are at a loss. Any handymen here?

The first close up picture below is under the drip edge laying on the foundation where water is under it.

The second picture is the drippings on the foundation. Some of this is just dripping off the metal drip edge, others its under it.

Is this a multiple story house? Are there any openings i.e. windows above the affected area? Looks like vinyl siding as well. Hate that stuff. It tells no stories.

 

[Cy4Patriots]

Is this a multiple story house? Are there any openings i.e. windows above the affected area? Looks like vinyl siding as well. Hate that stuff. It tells no stories.

Yes it’s Vinyl and there are windows above the deck but they also took off all the siding around there and retapped everything. It’s a ranch with a raised deck

 

[CYEATHAWK]

Yes it’s Vinyl and there are windows above the deck but they also took off all the siding around there and retapped everything. It’s a ranch with a raised deck

Vinyl siding over white plastic (tyvek) I would guess. Is the sheeting under the plastic all OSB or is it 1/2 rigid foamboard? When he removed the siding around the windows did he also remove the house wrap?

I lot of questions I know.....but with plastic siding, probably plastic house wrap and maybe even plastic sheeting.....sometimes taking it all off to the framing studs is the only way to find where it begins. Done it before and really the only way to make sure you don't have to go back and try again.

 

[Cy4Patriots]

Vinyl siding over white plastic (tyvek) I would guess. Is the sheeting under the plastic all OSB or is it 1/2 rigid foamboard? When he removed the siding around the windows did he also remove the house wrap?

I lot of questions I know.....but with plastic siding, probably plastic house wrap and maybe even plastic sheeting.....sometimes taking it all off to the framing studs is the only way to find where it begins. Done it before and really the only way to make sure you don't have to go back and try again.

It’s OSB board.

They took the top deck board off next to house and flashed it. It’s Z flashed above the deck board from the top and then flashed below the deck board

 

[oliver233]

From what you’re describing, it sounds like maybe the flashing isn’t properly directing water away, or there could be gaps where water’s sneaking in behind the siding. Sometimes water gets trapped if the siding or flashing isn’t sealed tightly or if there’s no proper drainage gap. You might want to check if there’s any way for water to get behind the flashing from above, like at the deck railing or where the deck attaches to the house.

 

[CYEATHAWK]

It’s OSB board.

They took the top deck board off next to house and flashed it. It’s Z flashed above the deck board from the top and then flashed below the deck board

For top remove siding, remove decking and flash ledger board. Flashing should be a minimum of 8 inches up exterior wall. House wrap should be over that then siding over that with a 1" gap off the deck floor. To properly flash below ledger board the flashing needs to be "z'd" behind the ledger, under the building paper and over the top of the first course of siding. To do that most times the ledger board needs to come off to get behind properly.

Somehow, somewhere upstream (window, siding.....deck) bulk water is getting behind the house wrap. More than likely due to wind blown rain. And because I doubt your house wrap is the old style 15/30lb tar paper it has nothing to absorb it and no where to go but down and into what ever will absorb it i.e. wood framing, sheeting.

 

[cyphoon]

The second picture is the drippings on the foundation. Some of this is just dripping off the metal drip edge, others its under it.

Might be wise to buy a cheap vinyl siding tool, peel up the bottom of the second or third course above the foundation flashing and verify that you see water behind the siding there. Rule out that water is simply wicking around that flashing and giving the illusion of a much bigger problem.

Windows and the ledger board flashing are likely culprits if the problem is legit. Another common problem area is where a gabled roof meets the side of the taller section of house. Even if that is flashed correctly, water flowing down the side of the house and gable seam can overwhelm the gutter and cause problem below. Kickout flashing in the gutter can help. Your problem seems kind of widespread for this to be the issue, but water is weird.

H