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Discussion Starter · #1 ·
Hi All, first time poster here but I've used the site plenty in the past. :thumbsup:

Pics tell more than words, so I've added plenty to describe the situation. We have a deck halfway over our breakfast nook and halfway over an outside overhang. We live in So. CA, so we don't get much rain, about a week a year, but this last rain we filled up a couple 5 gallon buckets inside the house, from water leaking though the ceiling. :eek: (We just bought the house earlier this year).

Here is the deck without the railing:



Look at these cracks!



What the deck looks like:



It was constructed with concrete on mesh, and then some sort of epoxy over the concrete:



Which led to this: :eek:



Water damage on the sheetrock. Of course there was a TON of mold, so I cleaned all that out. Joists are still in good shape though.



So I looked around and did some reading, and it seems that this should have been built using a sloped joists, with plywood on the top, a layer of EPDM, and then sleepers with rubber pads placed on top of the EPDM. The water then just runs through the boards and across the EPDM, and off the roof.

However, there isn't ANY slope at all to the deck. I would add the 1/8" slope, but at 10' that amounts to 1 1/4", which I don't have between the bottom of the sliding door:



So I'm not sure how to tackle this. I could build it the same way it was originally built, and replace it again in 10-15 years. The house is 25 years old, so I guess it lasted this long. Luckily we don't get much rain here, like I said only a week a year or so.

Thanks in advance for any suggestions!
 

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It looks like you could get the required space by removing the bottom molding from the door frame. Many times sliding doors don't use that anyway. Make sure you install new flashing against the house to the top of the new EPDM to prevent water penetration there.
 

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if you do not slope it properly you can be back in the same place.

per Section R905.12 of the 2009 International Residential Code (basis for the California Building Code) requires that thermoset roofing (EPDM is a thermoset roofing material http://www.nrca.net/consumer/types/thermos.aspx) have a minimum 2% slope or 1/4" per foot. You can verify this requirement with your building department.

R905.12 Thermoset single-ply roofing. The installation of thermoset single-ply roofing shall comply with the provisions of this section. R905.12.1 Slope. Thermoset single-ply membrane roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage. R905.12.2 Material standards. Thermoset single-ply roof coverings shall comply with ASTM D 4637, ASTM D 5019 or CGSB 37-GP-52M. R905.12.3 Application. Thermoset single-ply roofs shall be installed according to this chapter and the manufacturer's installation instructions.

Can you raise the height of the door to facilitate the proper construction of your deck? if so you can install a platform on the interior side. just a thought ......
 

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Discussion Starter · #5 · (Edited)
It looks like you could get the required space by removing the bottom molding from the door frame. Many times sliding doors don't use that anyway. Make sure you install new flashing against the house to the top of the new EPDM to prevent water penetration there.
That's not a bad idea. I suppose the deck could then be almost level with the floor in the bedroom, and I could notch the deck to fit around the door.

I was planning on reusing the existing flashing since it's bonded with the stucco, and I didn't want to risk damaging the stucco. In the image below, it shows the flashing underneath the EPDM. Is that incorrect? The plan was to nail the existing flashing down to new plywood, and install the EPDM over it.

if you do not slope it properly you can be back in the same place.

per Section R905.12 of the 2009 International Residential Code (basis for the California Building Code) requires that thermoset roofing (EPDM is a thermoset roofing material http://www.nrca.net/consumer/types/thermos.aspx) have a minimum 2% slope or 1/4" per foot. You can verify this requirement with your building department.

R905.12 Thermoset single-ply roofing. The installation of thermoset single-ply roofing shall comply with the provisions of this section. R905.12.1 Slope. Thermoset single-ply membrane roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage. R905.12.2 Material standards. Thermoset single-ply roof coverings shall comply with ASTM D 4637, ASTM D 5019 or CGSB 37-GP-52M. R905.12.3 Application. Thermoset single-ply roofs shall be installed according to this chapter and the manufacturer's installation instructions.

Can you raise the height of the door to facilitate the proper construction of your deck? if so you can install a platform on the interior side. just a thought ......
Thanks for pulling that code up. I saw online the 1/8" figure, and over the 10' deck, that amounts to 1 1/4" which I can swing by removing the fascia under the door. However, 2 1/2" would be too high, and raising the height of the door sounds like a lot more work than I'm willing to put into it. I think I can squeeze 1 3/4", so I will probably go with the tallest height I can get without needing to adjust the door.

Just curious, is this construction anything like you've seen in the past? That isn't to code, correct?

Thanks for the help guys. Your input, plus a good nights' sleep, and I think I've got a good game plan.
 

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I have a flat roof that is being re-sloped in a similar manner. The roofers I hired are using Isoboard (aka Isofoam) to make the slope. It is a rigid foam product that tapers in thickness. You put the isoboard down, then install the waterproof coating over that. You get a nice flat roof with the proper pitch, and an added benefit of some extra insulation.
 

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Discussion Starter · #7 ·
I have a flat roof that is being re-sloped in a similar manner. The roofers I hired are using Isoboard (aka Isofoam) to make the slope. It is a rigid foam product that tapers in thickness. You put the isoboard down, then install the waterproof coating over that. You get a nice flat roof with the proper pitch, and an added benefit of some extra insulation.
Isoboard sounds perfect... I was wondering how I would cut the shims thin enough to slope the plywood. I'm guessing the "foam" is strong enough to support the deck/people/furniture/etc..?

Any idea where you get the Isoboard from? Thanks for the input! :thumbsup:
 

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make sure if you put down EPDM membrane to attach strips of the membrane onto the bottom of your sleepers so that you have membrane to membrane and not wood to membrane. patented is correct on the sloped isoboard.

could also consider a vinyl membrane product that you can walk on directly, would eliminate sleepers. http://www.duradeckinc.com/
 

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Discussion Starter · #9 ·
make sure if you put down EPDM membrane to attach strips of the membrane onto the bottom of your sleepers so that you have membrane to membrane and not wood to membrane. patented is correct on the sloped isoboard.

could also consider a vinyl membrane product that you can walk on directly, would eliminate sleepers. http://www.duradeckinc.com/
I saw in the article to attach the strips; thanks for the info!

I think I'd like to go with a deck. Seems like it'd look nicer.
 

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could also consider a vinyl membrane product that you can walk on directly, would eliminate sleepers. http://www.duradeckinc.com/
That product is not a roofing membrane. It's a coating designed for application on top of concrete slabs. Not something to consider using for this application.
 

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Discussion Starter · #14 ·
Looks like a good system, and it would save time on large applications. But for my 10' x 21' area, the need to buy the hot-air gun to weld the sheets together would probably be too expensive.

I called the local Home Depot and they should be able to order the Isoboard. They're going to get back to me with the pricing.
 

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Deck with problems

We've installed Duradek Vinyl membrane which is an IRC (International Residental Code) approved "Walkable" roof membrane or over 17 years, never had to replace one. We see a lot of this expanded metal business - not so cheep or great when you get this problem. The Slope is a new
CBC code (CABuilding Code) requirement, as well as any deck like this needs to be a Class A fire rated "deck", which became law in 2012 January.

Perhapse you can shave down the joists a bit on that 10 foot run and get some slope, 1/8" in 12" is a MINIMUM! Keep in mind you should remove up to 8" of the stucco and install ANY membrane up behind the building wrap (assuming you have wrap), then install a new stucco screed and keep that
transition deck to wall at the ledger from being the problem area in future.

Too bad you can't do it the "best way possible", Looks like you're in Hemmit or somewhere - beautiful but hot.
 

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Why does the slope have to have the high side at the door?
Can't you start it high at the far wall away from the door and taper it down towards the end where the door is.
Maybe add a little compound slope in front of the door to keep the water away from the door?

Just a thought from outside the box. ( maybe too far outside?)
 

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Discussion Starter · #18 ·
We've installed Duradek Vinyl membrane which is an IRC (International Residental Code) approved "Walkable" roof membrane or over 17 years, never had to replace one. We see a lot of this expanded metal business - not so cheep or great when you get this problem. The Slope is a new
CBC code (CABuilding Code) requirement, as well as any deck like this needs to be a Class A fire rated "deck", which became law in 2012 January.

Perhapse you can shave down the joists a bit on that 10 foot run and get some slope, 1/8" in 12" is a MINIMUM! Keep in mind you should remove up to 8" of the stucco and install ANY membrane up behind the building wrap (assuming you have wrap), then install a new stucco screed and keep that
transition deck to wall at the ledger from being the problem area in future.

Too bad you can't do it the "best way possible", Looks like you're in Hemmit or somewhere - beautiful but hot.
Thanks for the info on the code requirement. I looked around for the vinyl membrane, but I'm having trouble locating it in such a small surface area. Some companies only sell to licensed installers, and others sell rolls of 10'x100' or more... WAY more than I need!

As far as shaving the joists down... I'm uneasy doing that. I don't think I could get them level enough, and they already seem undersized for the job. I am going to try getting the height up more than the 1/8" /ft. I'm going to try more along the line of 3/16"-1/4".

I was trying to avoid removing stucco... But from the sound of your message, I'm guessing that's not an option. I thought the 2-3" I could get behind the flashing would be OK, but it sounds like you're recommending more like 6".

I like in the unincorporated mountains west of Hemet, south of Lake Mathews. It is beautiful but it does get a bit warm... This weekend when I was tearing the deck down it was 98-100° out.

Why does the slope have to have the high side at the door?
Can't you start it high at the far wall away from the door and taper it down towards the end where the door is.
Maybe add a little compound slope in front of the door to keep the water away from the door?

Just a thought from outside the box. ( maybe too far outside?)
It's always good to think outside the box. :thumbsup:

We have eaves that cover the house on the sides, so that should do nicely on keeping the water away from the side (wind may blow it in, but at least it won't naturally run toward the house). I kinda want to keep it that way...

And a compound slope? Now you're starting to scare me....
 

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I was thinking that if you slope it the full amount the long way, you could put a smaller slope away from the door. Just to keep the water flowing away. So the shims would taper from 2" down to nothing on the long axis but the two closest to the door might taper from 2" down to 1"across the door area.
Not a builder so I can come up with these and someone else gets to tell me I'm crazy.
 

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Discussion Starter · #20 ·
Hmmmm..... It'd be easy to cut the isofoam and create the compound slope, and then cover it with the EDPM. The hard part would be cutting the sleepers to account for the compound angle....

The Depot hasn't called me back yet. I'm about to give them a ring and see what they found out with the Isofoam.
 
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