Sophie's Choice: No slope or no step down on deck.

2076 Views 29 Replies 5 Participants Last post by ron45, Jun 11, 2020

vaiek

Discussion Starter · Jun 9, 2020

I now bring you the next episode of "Eric Builds A Deck"

Ok, so thanks to the wisdom of this community and a little additional research on the LedgerLok engineering specs, it seems securing my ledger to the 1" OSB rim is AOK, or I can cut out the OSB rim and put a 2x rim joist on the sill plate secured with blocking between the joists.

But now I face one more conundrum.

Given (1) that the bottom row of fasteners must be 6.5" from the top of the ledger according to figure R507.2, but not less than 2" from the bottom of the rim, and (2) that a step must be be at least 4" tall to not constitute a trip hazard (if I understand correctly), and (3) my deck is L shaped with the door in the inside corner of the L, I am left with the following options.

A. No step and slope the deck for drainage. Pros: Draininage. Cons: possible snow build up and moisture invasion of the sill/house.

B. A 4" step, but no slope for drainage. Pros: Step helping to protect the sill/house. Cons: No run off of water.

I attach a drawing detailing the two scenarios:

So which is the better of two evils? (Note that I am using composite decking with spaces so maybe the slope is not that important as long as it is definitely not sloped TOWARD the house?)

-Eric

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Nealtw

· #2 · Jun 9, 2020

vaiek said:
I now bring you the next episode of "Eric Builds A Deck"

Ok, so thanks to the wisdom of this community and a little additional research on the LedgerLok engineering specs, it seems securing my ledger to the 1" OSB rim is AOK, or I can cut out the OSB rim and put a 2x rim joist on the sill plate secured with blocking between the joists.

But now I face one more conundrum.

Given (1) that the bottom row of fasteners must be 6.5" from the top of the ledger according to figure R507.2, but not less than 2" from the bottom of the rim, and (2) that a step must be be at least 4" tall to not constitute a trip hazard (if I understand correctly), and (3) my deck is L shaped with the door in the inside corner of the L, I am left with the following options.

A. No step and slope the deck for drainage. Pros: Draininage. Cons: possible snow build up and moisture invasion of the sill/house.

B. A 4" step, but no slope for drainage. Pros: Step helping to protect the sill/house. Cons: No run off of water.

I attach a drawing detailing the two scenarios:

So which is the better of two evils? (Note that I am using composite decking with spaces so maybe the slope is not that important as long as it is definitely not sloped TOWARD the house?)

-Eric

You missed option C, Remove rim, add blocks replace rim, add ledger one step down from house floor.

vaiek

Discussion Starter · #3 · Jun 9, 2020

Nealtw said:
You missed option C, Remove rim, add blocks replace rim, add ledger one step down from house floor.

Ah, but removing the rim does not eliminate my math problem as the new rim/blocks will be in the same location as the old OSB Rim. Unless I cut out a slice of foundation wall while I am at it. :biggrin2:

Unless I am missing something, which is completely possible.

-Eric

Nealtw

· #4 · Jun 9, 2020

vaiek said:
Ah, but removing the rim does not eliminate my math problem as the new rim/blocks will be in the same location as the old OSB Rim. Unless I cut out a slice of foundation wall while I am at it. :biggrin2:

Unless I am missing something, which is completely possible.

-Eric

You have to replace the rim before you add the ledger the new rim will be a 2x10.

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vaiek

Discussion Starter · #5 · Jun 9, 2020

Nealtw said:
You have to replace the rim before you add the ledger the new rim will be a 2x10.

Yes, sir. But that still does not allow me to go any lower with my ledger does it? So while I have a sturdier rim joist, I still cannot have both a step down and slope for drainage, right?

-Eric

kwikfishron

· #6 · Jun 9, 2020

Where's the flashing details in any of those options?

If you're in Michigan you need a step down to handle any snow build up on the deck.

If the deck is totally covered and will never see snow then not so much but once again...Where's the flashing (the most important detail)?

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Nealtw

· #7 · Jun 9, 2020

vaiek said:
Yes, sir. But that still does not allow me to go any lower with my ledger does it? So while I have a sturdier rim joist, I still cannot have both a step down and slope for drainage, right?

-Eric

Unless you are doing a solid surface deck you don't need a slope.

I am not understanding the problem If you remove some rim, add blocks and replace rim with 2x10, and cover that with house wrap it will be identical to what you have now.

If you can't see it as being identical, Step back and read the posts again.
You are stuck understanding something with out reading the details

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Nealtw

· #8 · Jun 9, 2020

kwikfishron said:
Where's the flashing details in any of those options?

If you're in Michigan you need a step down to handle any snow build up on the deck.

If the deck is totally covered and will never see snow then not so much but once again...Where's the flashing (the most important detail)?

I was hoping to clear up confusion before adding more for him to think about. :biggrin2:

vaiek

Discussion Starter · #9 · Jun 9, 2020

Nealtw said:
Unless you are doing a solid surface deck you don't need a slope.

I am not understanding the problem If you remove some rim, add blocks and replace rim with 2x10, and cover that with house wrap it will be identical to what you have now.

If you can't see it as being identical, Step back and read the posts again.
You are stuck understanding something with out reading the details

There is no problem. I see it as identical. "No slope needed" was the missing puzzle piece. Thank you sir!

vaiek

Discussion Starter · #10 · Jun 9, 2020

kwikfishron said:
How come I don't see flashing details in any of the options?

If you're in Michigan you need a step down to handle any snow build up on the deck.

If the deck is totally covered and will never see snow then not so much but once again...Where's the flashing (the most inportant step)?

Yes I left out the flashing in the diagrams. There will be 30# felt behind the ledger and the top of the ledger will be flashed with z-flashing (which will in turn be tucked behind the house wrap and vinyl siding that comes down to the decking).

The deck is not totally covered (and is in Michigan), so it sounds like the way to go is with a step down and no slope. Thank you!

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kwikfishron

· #11 · Jun 9, 2020

Nealtw said:
I was hoping to clear up confusion before adding more for him to think about. :biggrin2:

Oki Doki, I'm out.....

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Nealtw

· #12 · Jun 9, 2020

vaiek said:
There is no problem. I see it as identical. "No slope needed" was the missing puzzle piece. Thank you sir!

We do mostly solids surface here so we do the the step down and the slope.
The beam end is just lower than the ledger:wink2:

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ron45

· #13 · Jun 9, 2020

Am I missing something.?

Since when did OSB become acceptable in supporting lateral force.?

ron45

· #14 · Jun 9, 2020

ron45 said:
Am I missing something.?

Since when did OSB become acceptable in supporting lateral force.?

It's to my understanding those lags must be into a floor joist.

Nealtw

· #15 · Jun 9, 2020

ron45 said:
It's to my understanding those lags must be into a floor joist.

It's a TGI system I joists. :wink2:

vaiek

Discussion Starter · #16 · Jun 9, 2020

ron45 said:
It's to my understanding those lags must be into a floor joist.

I am probably using the term OSB incorrectly. According to the LedgerLOK installation technical bulletin, the ledger fasteners can be screwed into the rim where the rim material may be "2 x _ Spruce-Pine-Fir lumber or 1" minimum Engineered Wood (EW) Rim. EW Rim material must be solid LVL, LSL or PSL. For wood rims, all species above 0.42 specific gravity allowed."

I am assuming what I have is one of those engineered boards based on my other post.

Nealtw

· #17 · Jun 9, 2020

vaiek said:
I am probably using the term OSB incorrectly. According to the LedgerLOK installation technical bulletin, the ledger fasteners can be screwed into the rim where the rim material may be "2 x _ Spruce-Pine-Fir lumber or 1" minimum Engineered Wood (EW) Rim. EW Rim material must be solid LVL, LSL or PSL. For wood rims, all species above 0.42 specific gravity allowed."

I am assuming what I have is one of those engineered boards based on my other post.

It is an LSL but our engineers would never approve it.

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3onthetree

· #18 · Jun 9, 2020

vaiek said:
I am probably using the term OSB incorrectly. According to the LedgerLOK installation technical bulletin, the ledger fasteners can be screwed into the rim where the rim material may be "2 x _ Spruce-Pine-Fir lumber or 1" minimum Engineered Wood (EW) Rim. EW Rim material must be solid LVL, LSL or PSL. For wood rims, all species above 0.42 specific gravity allowed."
.

Yes propietary brands LSL rim board (e.g. TrusJoist) are engineered to have the same properties as a sawn 2x. If you have an engineered rim board and not 3/4" OSB plywood, you should be able to attach your ledger to it (AHJ confirmation of course). Look for stampings inside to find the brand/size/ANSI designation.

Nealtw said:
You have to replace the rim before you add the ledger the new rim will be a 2x10.

Neal, I don't understand the cutting out of the existing rim board to put in a 2x10 which is not as tall as the Ijoist. The lateral restraint (rim board) needs to be full height of the joist. Code basically defers to manufacturer's engineering, so unless that is a detail issued by them where this 2x10 block is only between the web, I don't see how that could fly.

Reactions: 1

Nealtw

· #19 · Jun 9, 2020

3onthetree said:
Yes propietary brands LSL rim board (e.g. TrusJoist) are engineered to have the same properties as a sawn 2x. If you have an engineered rim board and not 3/4" OSB plywood, you should be able to attach your ledger to it (AHJ confirmation of course). Look for stampings inside to find the brand/size/ANSI designation.

Neal, I don't understand the cutting out of the existing rim board to put in a 2x10 which is not as tall as the Ijoist. The lateral restraint (rim board) needs to be full height of the joist. Code basically defers to manufacturer's engineering, so unless that is a detail issued by them where this 2x10 block is only between the web, I don't see how that could fly.

Well that is what we did to repair one that had been bolted to just an LSL
For what ever reason the deck had pulled lag bolts out, We had to move the whole deck to make the repair.. Engineer designed repair.

Nealtw

· #20 · Jun 9, 2020

With all said, a discussion with the inspector ahead of time would be in order.

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