# How do I waterproof a sill under grade level?



## kwikfishron (Mar 11, 2010)

How far does the rot go past the door? Does it run the entire length of the house? In what I can see in your picture your grade doesn't look like It's above the bottom of the stucco. Plate line our the top of your foundation "should" be a inch or so above the bottom of the stucco, is it?

Ron


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## Tom Struble (Dec 29, 2008)

short of rebuilding all the affected walls using materials that can be directly buried in the ground,you can't really waterproof this detail

you should excavate that whole area to at least 6-8'' below the foundation
sloping the excavated area away from the house,install a retaining wall and proper drainage...may as well fix it right and be done with it


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## Semi - pro (Mar 14, 2010)

The rot extends the entire back side where the patio meets the house, about 48'. I've removed the bluestone and jack hammered the patio out 24" from the house. The hole shown in the picture is the missing sill on the bottom. The stucco, now removed to above the rim joist, used to extend to about the sill level.




kwikfishron said:


> How far does the rot go past the door? Does it run the entire length of the house? In what I can see in your picture your grade doesn't look like It's above the bottom of the stucco. Plate line our the top of your foundation "should" be a inch or so above the bottom of the stucco, is it?
> 
> Ron


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## kwikfishron (Mar 11, 2010)

How about a new pic. of what it all looks like now.


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## Semi - pro (Mar 14, 2010)

I'd need to remove the entire patio area (16'x48') to get a drainage grade. I'm reluctant to destroy the patio before I explore other options. 

I suspect there is a solution to this problem since I'm not the only one out there in the Northeast with a patio level close to inside floor level. 

How about it you pool owners out there?



tomstruble said:


> short of rebuilding all the affected walls using materials that can be directly buried in the ground,you can't really waterproof this detail
> 
> you should excavate that whole area to at least 6-8'' below the foundation
> sloping the excavated area away from the house,install a retaining wall and proper drainage...may as well fix it right and be done with it


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## tpolk (Nov 7, 2009)

maybe a 3' wide french drain system at house leaving finished gravel flush with patio. then its just a matter of a good waterproofing system at house


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## Tom Struble (Dec 29, 2008)

waterproofing a wood/stucco house at the bottom,has the potential to become the ''rubber boot''scenario,if your going to dig a 3' trench anyway you may as well fix the grade the way its supposed to be

lotta work for sure,but this is your house not a garage or a shed out back


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## kwikfishron (Mar 11, 2010)

I’ve been a siding contractor/ builder on the Oregon Coast for to many years and have seen this problem many times. Code around here is that grade be no higher than 6” below the top of the foundation. Since you don’t have that and your hoping to find a solution without excavator ripping your yard up and regardless how you choose to put your new ditch back together with a number of different drain options your ultimate goal is to 

“Protect The House” 
​and not completely rely on a drain system in this case. Since you said that you have already ripped up some stucco this is what I would do and have done many times.
After you have repaired the framing run a piece of Stainless Flat Stock over the sheathing however wide it needs to be to lap over the foundation 3-6” and above grade at least 6” and under the felt or membrane of the stucco. I’d even run a big fat bead of Blackjack or something against the foundation under the flashing so water can’t seep up.
In the area of those big glass doors you need a “Stainless Door Pan“.
If your not familiar with them It’s a cap for the bottom of the doors. It covers the entire opening and flanges up about ½” on the sides and on the inside of the house and flanges down about 1 ½” on the outside of the house. It’s that outside flange were you will tuck the flat stock flashing under. Yes you will have to remove and re-install the doors to do this but it’s the only way to positively keep water from getting to the sheathing. A pan can be made up at any local sheet metal shop. You defiantly want to measure for the pan twice or thrice, it needs to be right. You want it be a little wider than the door but not to wide to be tight in the framing and just slightly wider front to back so you have room to get your other flashing under the front flange.
I would definitely go Stainless Steel on all of it, Galvanized will fail over time in this application. If you have to go galvanized at least sheet the affected part of the wall with treated.


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## Tom Struble (Dec 29, 2008)

I suspect there is a solution to this problem since I'm not the only one out there in the Northeast with a patio level close to inside floor level.
How about it you pool owners out there?[/quote said:


> probably wondering how to fix their house:huh:


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## Semi - pro (Mar 14, 2010)

I promised updates as they come along:
I spoke today to Randy in tech support at Marflex 513-422-7285. He suggested a waterproof coat to both the foundation and wood. Then cover with a peel and stick waterproof membrane (that sounded like Grace ice and water shield but for foundations). His products are distributed through AHHarris locally. I asked if I could use his name on this website and he said yes. I tiold him if the products don't work I'll post that too and he still seemed enthusiastic. 

He also agrees that the perforated drains should be replaced with solid pipe and that additional perforated pipe be installed as a separate system. This way roof water through gutters can not be introduced to the gravel under the concrete patio layer. It also means I need another day with HD's rental jackhammer - UGGG.

He seemed very confident in his recommendation and offered to write a letter of suitability, if necessary, that might be useful for a building inspector or in the eventual sale of the house. 

Next updates will be what is actually done and if it works.


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## kwikfishron (Mar 11, 2010)

That is basically the same thing I told you, the only difference is using is the ice and water (the product he’s a rep. for) instead of the stainless steel flat stock. Stainless Steel is forever (or at least a lot longer than we’ll be around) don’t get me wrong the other is good stuff but can tear, especially with rock against it. I’d price it both ways.

I’ll still always be adamant about door pans. When water blows up under the sill what keeps it from getting behind the paper and to the sheathing, a bead of calk? I can’t count how many doors I’ve pulled and rotten sills (and more) I’ve replaced that wouldn’t have been necessary if there was a pan. It’s a different thing if you have a big overhang like in most entry’s so that the weather isn’t pounding the door.

We have hurricanes on the Oregon Coast but for some reason they just call it rain.


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## stadry (Jun 20, 2009)

miradrain & asphalt cement,,, for a sketch, either tremco or my w-site IF its not too late,,, note - IF you don't provide a pathway for the water to drain, it'll just sit there & the conc'll suck it up thru capillary action.

according to aci, conc's NOT wtrproof til compressive reash's 5,000psi.

good luck !


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## kivnic (Mar 4, 2012)

Old post but hoping you're still monitoring it @kwikfishron 😄 (though, advice from any expert is welcome). Need to do a repair like this at a 100 year house I just bought. The driveway, and some expensive hardscape work, are finished above the mudsill grade (~30 liner ft). I discovered that the planters next to the house had buried two rows of siding in the dirt. After reading this thread, my plan is to excavate to the footing, install a footer drain, then waterproof both the foundation and 6" of wooden house sheathing. I'll then replace the two rows of cancelled siding with stucco. I understand that this setup will probably need to be serviced in the future but, my hope is to go 30 years or so before needing to do it again.

Getting 30'x12" of stainless steel flat stock is prohibitively expensive. Will this 2mil thin stainless steel stick on flashing (York 304 SS) work instead?





York 304 SA – York Flashings







www.yorkmfg.com





Also, is it better to put the flashing below the liquid membrane or on top of the membrane?


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## XSleeper (Sep 23, 2007)

@kivnic 

You would need a clean dry surface, then apply a primer and a product like Blueskin WP200.


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## Nealtw (Jun 22, 2017)

With primer peel and stick will seal the wood and the concrete.


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## kivnic (Mar 4, 2012)

Are you guys saying to use the peel and stick (ie, Blueskin WP200) instead of stainless steel flashing? 

Also, I was planning to coat the foundation, top to bottom, in Blackjack #57 (or similar) since I'm installing a footer drain. Should I take the blackjack up over the wood 6" before I install the peel and stick flashing?

Related, after I get everything nice and clean, is it important that I do a parge coat to smooth the old concrete out? In most of the YouTube videos I watch about footer drains, they don't seem concerned that the concrete is irregular when they put the blackjack coat on. However, when I check the instructions for liquid membranes they seem to imply that you should parge first. I'm planning to do spot repairs if needed but really don't want to spend the time parging the whole surface if it's not essential. What do you guys think?


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