Search the forums

Loading
Home › Forums › Breaktime › Construction Techniques

Concrete Slab Soaking Up Water ???

doormatt's picture

Concrete Slab Soaking Up Water ??? (post #205523)

doormatt on Thu, 12/22/2011 - 20:54
in

I'm in the process of reframing and siding a walkout basement wall.  The wall is constructed with 2x4 stud framing and zip system sheathing.  The wall is framed on a basement slab (concrete slab on grade).  All sheating panel joints are tapped and I have a 6" strip of Grace Vycor running around the base of the wall (3" up sheating and 3" down exterior edge of slab).  We've had some heavy rains today and now the PT 2x4 sill plate is wet in areas.  There's also a couple of wall studs that are wet along the outter bottom edge of the stud where it meets the sill plate.  Is it possible for the conrete slab to soak up enough water to allow the wood framing to become this wet?  Any other ideas of how this could happen?

I've attached a couple of pictures showing what has happend.  The dark areas on the sill plate are wet.  I didn't feel any moisture on the back side of the sheathing - only the sill plate.

If it is the concrete soaking up water, how do I fix this?  I've seen details where plastic sheeting gets attached to the wall and then run about 2-3 feet out from the house/foundation... is this the fix?

I appreciate any advice or suggestions offered.

-A +A

door (post #205523, reply #1 of 48)

by calvin in reply to doormatt [original] on Thu, 12/22/2011 - 21:01

How'd you deal with the waterproofing of the foundation and was the backfill stone?

How far is finished grade in relation to the top/bottom of the slab?

Was the slab turned down to the footing?

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


http://www.quittintime.com/

 

Before I started all this the (post #205523, reply #3 of 48)

by doormatt in reply to calvin [original] on Fri, 12/23/2011 - 09:02

Before I started all this the existing grade was actually higher than the floor slab.  After removing the exisiting siding I dug down the grade so that it's now about 6" below the top of slab and slopped away from the house.  At this location it's a turn-down slab over a stip footing with backfilled soil - no stone (yet).

However, with the wall in it's current state (sheathing only with no siding yet), the sheathing comes down the wall and flushes out with the edge of the slab.  So all the heavy wind blown rain that hits the wall will run down the sheathing and down the exteriof face of the turn down slab.  Would this be enough rain water to do this?

details (post #205523, reply #4 of 48)

by Jigs-n-fixtures in reply to doormatt [original] on Fri, 12/23/2011 - 10:52

The sheathing and house wrap should extend about 1/2-inch below the slab grade so that the rainwater is guided past the top of slab. 

In a wet climate such as Portland or Seattle you wooul also put a strip of wrap under the sill plate and then wrap it back up under the wrap on the sheathing to limit the water penetration. 

Cured concrete will absorb and transmit moisture, but it shouldn't be very liquid permeable.  A lot of water rewervoirs, and pipes are made of concrete. 

existing conditions (post #205523, reply #5 of 48)

by doormatt in reply to Jigs-n-fixtures [original] on Fri, 12/23/2011 - 17:01

If I were able to completely rebuild the wall I would have done that.  However, the existing stud framing was set back 1/2" from the slab edge.  So when the sheathing was installed it worked out to be flush with the slab edge and unable to extend below.  I was worried about the water running down the sheathing and wicking back under to the studs so I installed the 6" strip of Grace around the base to cover the transition between framing and slab.  With the studs already in place I wasn't able to put anything under the sill plate either.

I've added a photo from the exterior showing what conditions are like.

PreviewAttachmentSize
ext_1.JPG
ext_1.JPG459.86 KB

It looks like the housewrap (post #205523, reply #7 of 48)

by Piffin in reply to doormatt [original] on Fri, 12/23/2011 - 18:35

It looks like the housewrap is not lapped over the vycor

 

 


or try this site for the whole gang

http://forums.delphiforums.com/breaktimeclass/start

No Housewrap (post #205523, reply #8 of 48)

by doormatt in reply to Piffin [original] on Fri, 12/23/2011 - 19:43

I'm using the Zip System wall sheathing - no housewrap required.  (http://www.zipsystem.com/zip-system/wall...)

I've also verified that the Grace Vycor, which extends about 3" down the face of the slab, is sealed to the sheathing.

The photos of water leaks (post #205523, reply #9 of 48)

by Piffin in reply to doormatt [original] on Fri, 12/23/2011 - 20:05

The photos of water leaks suggest otherwise

 

 


or try this site for the whole gang

http://forums.delphiforums.com/breaktimeclass/start

Water behind Grace (post #205523, reply #10 of 48)

by doormatt in reply to Piffin [original] on Sat, 12/24/2011 - 13:16

The Grace Vycor appears to be fully adhered to the sheathing the best I can tell.  Is it common for water to get behind Grace in this type of application?  If the Grace won't work, what should be done in this application?

Yes, an uphill facing lap (post #205523, reply #12 of 48)

by Piffin in reply to doormatt [original] on Sat, 12/24/2011 - 14:13

Yes, an uphill facing lap will leak sooner or later, more or less, but it WILL leak

 

 


or try this site for the whole gang

http://forums.delphiforums.com/breaktimeclass/start

something is not kosher (post #205523, reply #14 of 48)

by calvin in reply to doormatt [original] on Sat, 12/24/2011 - 15:03

Stand back and take an overall shot-mark the photo or mark the spot in the shot that corresponds with the leak area.

Do it from in and out.

Maybe something will jump out at this group of fine adults.

 

thanks.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


http://www.quittintime.com/

 

How far above grade is the (post #205523, reply #2 of 48)

by DanH in reply to doormatt [original] on Thu, 12/22/2011 - 21:26

How far above grade is the top of the slab?  How is the drainage around the slab?


We are like tenant farmers chopping down the fence around our house for fuel when we should be using Nature's inexhaustible sources of energy -- sun, wind and tide. ... I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait until oil and coal run out before we tackle that. --Thomas Edison

new photo (post #205523, reply #6 of 48)

by doormatt in reply to DanH [original] on Fri, 12/23/2011 - 17:03

I added another photo showing the exterior condition.  Everything is sloped to drain away from the foundation.

Makes little difference. That (post #205523, reply #11 of 48)

by Piffin in reply to doormatt [original] on Sat, 12/24/2011 - 13:50

Makes little difference. That much water does not wick UP, and a lap facing uphill is not secure against water unless it is welded.

There are also nail holes and butt joints and the top of that sheathing to let water in

 

 


or try this site for the whole gang

http://forums.delphiforums.com/breaktimeclass/start

The water is coming from (post #205523, reply #13 of 48)

by florida in reply to doormatt [original] on Sat, 12/24/2011 - 14:53

The water is coming from above no matter what you can or can't see. if it were my house I'd go ahead and run some felt on that wall then water test it.

My goal in using the Zip (post #205523, reply #15 of 48)

by doormatt in reply to florida [original] on Sun, 12/25/2011 - 18:43

My goal in using the Zip System was to avoid having to use any type of housewrap.  I know the system is used everywhere with success.  I'm convinced the water has to be entering from either behind the grace or working it's way up from the slab.  None of the framing or sheating above the sill plate show any signs of water (except for what the studs have soaked up from the plate).  I think it's time I get out the garden hose and see if I can trace it.

I know it's not typical practice to use uphill facing laps, but the Zip System is designed for that type of tape.  All the seams in the sheathing are sealed with Zip Tape... and if anyone is familiar with this product, they'll understand when I say this stuff really seals up tight.  I just can't see any possible way water could be getting in from any of the sheathing seams.

I'll take another look at the Grace Vycor lap between the sheating and the slab - that may be the cause.  I've heard nothing but good stuff about Grace products and from what I can tell it appears to be well adhered to the sheathing, but maybe I missed something.

One solution I've thought about is using a silicone adhesive to attach plastic sheating to the base of the wall sheating, extend the plastic down the face of the slab and slope outward from the foundation a few feet, then come back and cover with stone to allow drainage.  I would also run a line of Zip Tape along the seam between the plastic and the wall sheathing.  Heck, I may even apply a liquid sealer to the exterior slab edge too... I want to ensure this doesn't leak!

Thanks for all the help and suggestions!

I don't think that much (post #205523, reply #16 of 48)

by DanH in reply to doormatt [original] on Sun, 12/25/2011 - 23:14

I don't think that much moisture could have worked its way up through several inches of concrete in a relatively brief period of time -- somehow the moisture is being delivered to the top of the slab from above.  But keep in mind that the moisture may travel several feet along the bottom plate from where it enters to where you see it. 


We are like tenant farmers chopping down the fence around our house for fuel when we should be using Nature's inexhaustible sources of energy -- sun, wind and tide. ... I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait until oil and coal run out before we tackle that. --Thomas Edison

door (post #205523, reply #17 of 48)

by calvin in reply to doormatt [original] on Mon, 12/26/2011 - 10:34

I'll ask again, show some pictures of the whole wall in/out and locate you water problem areas.

thanks.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


http://www.quittintime.com/

 

If he would simply spend as (post #205523, reply #19 of 48)

by Piffin in reply to calvin [original] on Mon, 12/26/2011 - 21:48

If he would simply spend as much time shooting a cople good photos and running tarpaper or wrap on that wall as he is arguing that it can't be leaking, he would be done and moving on by now

 

 


or try this site for the whole gang

http://forums.delphiforums.com/breaktimeclass/start

Sorry for the delay - today (post #205523, reply #20 of 48)

by doormatt in reply to calvin [original] on Tue, 12/27/2011 - 14:24

Sorry for the delay - today was the first time I've been home during daylight hours when it wasn't raining and able to take photos.

Photos are taken in the same order/direction exterior and interior.  I've marked each photo where I've found a wet sill plate.  All seams/joints in the Zip Sheathing has the Zip Tape.  The felt paper at the top of the wall is tucked under the existing siding to keep the original osb sheathing dry.

If better photos of a certain area are needed, just let me know.

Thanks!

PreviewAttachmentSize
int_1.jpg
int_1.jpg764.61 KB
int_2.jpg
int_2.jpg590.56 KB
int_3.jpg
int_3.jpg751.42 KB
int_4.jpg
int_4.jpg672.69 KB
out_1.jpg
out_1.jpg729.9 KB
out_2.jpg
out_2.jpg740.59 KB
out_3.jpg
out_3.jpg718.29 KB

"the Zip System is designed (post #205523, reply #18 of 48)

by Piffin in reply to doormatt [original] on Mon, 12/26/2011 - 21:40

"the Zip System is designed for that type of tape."

 

Sure, and it only works perfectly when it is applied perfectly which it never is.

 

I have been doing water proofing  work and repairing failures from others for over forty years now. I have never seen a reverse lap that did not leak soner or later

 

 


or try this site for the whole gang

http://forums.delphiforums.com/breaktimeclass/start

I'm not arguing that it's not (post #205523, reply #21 of 48)

by doormatt in reply to Piffin [original] on Tue, 12/27/2011 - 14:39

I'm not arguing that it's not leaking - it obviously is because it's wet on the interior.  I'm just not convinced it's leaking from anything above.  I've thoroughly checked all framing above and nothing is wet and there are no signs of water.

I take it you're not a fan of the zip system?  I know the system only works when the tape has been properly installed.  I can assure you I've taken the time necessary to ensure the zip tape has been installed properly, rolled and fully bonded to the zip panels.  I've seen installs where the tape was just thrown up without care and it looks sloppy... I could see leaks in that type of install.

So far it sounds like concrete would not allow this much moisture to be absorbed... so I believe it's got to be the Grace (with reverse lap) that is leaking.  If anything else stands out from the photos, please let me know.

I'm very detailed about my work and will loose sleep at night knowing there is a leak, so I am committed to resolving this.  I'm just hoping there is a solution without having to wrap the entire wall - that was the point of using the zip system in the first place.

I think the grade is too high (post #205523, reply #22 of 48)

by MarkH in reply to doormatt [original] on Tue, 12/27/2011 - 14:49

I think the grade is too high in the leaking area.  Also it looks like there is exposed concrete ledge for water to sit on and penetrate under the wall. 

Originally the soil was (post #205523, reply #24 of 48)

by doormatt in reply to MarkH [original] on Tue, 12/27/2011 - 14:59

Originally the soil was 8"-12" above the floor slab before I started this project, but now it's graded down.  The top of the basement concrete slab is about 6" above the concrete ledge/footing and then the soil slopes away from their (see ext_1.jpg photo).  That was my concern about the concrete soaking up the water because it could run back under the slab at these areas.

Well, try some concrete (post #205523, reply #27 of 48)

by MarkH in reply to doormatt [original] on Tue, 12/27/2011 - 15:25

Well, try some concrete waterproofing, or use the time tested approach of putting plastic on top of the slab to see if water appears under or on top of the plastic.  Then you may have an answer.

I would put felt on the (post #205523, reply #23 of 48)

by MarkH in reply to doormatt [original] on Tue, 12/27/2011 - 14:57

I would put felt on the outside if I built it.  I haven't read this thread closely, so I don't know why you don't want a proper weather barrier.

From what I've read, the zip (post #205523, reply #25 of 48)

by doormatt in reply to MarkH [original] on Tue, 12/27/2011 - 15:02

From what I've read, the zip system is supposed to be a superior system for protection from weather.

I've read the same thing, but (post #205523, reply #26 of 48)

by MarkH in reply to doormatt [original] on Tue, 12/27/2011 - 15:18

I've read the same thing, but I should have been named Thomas, because, well, you know.

Door. (post #205523, reply #28 of 48)

by calvin in reply to doormatt [original] on Tue, 12/27/2011 - 15:49

Just back from a lovely time in Nashville-and took a quick look at last set of photo[s

 

From that quick scan I see a door above that's near above the panel?

And the lower door, that has leak on either side of it. 

How did you detail those doors?  Sill pan and NO LEAK down the sides or at the top?

 

I ask because if water can enter there at the door---------------

It could work over to the corner (in the panel shot)-down the corner and then under the plate-to it's lowest spot-sit and wick up the plate/stud/back of sheeting.

In the other-same thing-with your caulking on the interior of the plate-it might not turn up at it's source-but be forced to flow to a low spot.

How is that slab for flat and level out where the walls sit?

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


http://www.quittintime.com/

 

All of the doors located on (post #205523, reply #29 of 48)

by doormatt in reply to calvin [original] on Tue, 12/27/2011 - 16:55

All of the doors located on the upper level are in really bad shape.  They will be replaced once the new deck is built - after the siding is up on the basement wall.  I suppose it is possible that those could be the source.  The water would have to run down the corner studs where it's not visible from the inside because I haven't been able to find any signs of water on any of the framing above the sill plate so far.

When I installed the new door at the basement level I taped and flashed around the entire opening, caulked behind the door flanges, and then caulked the perimeter.  I'll take a closer look at that and see if that could be the source.  The slab appears level to my eye, but I can see your point where it would drain to a low spot and then show on the sill plate.

Thanks for the suggestions!

Lower door? (post #205523, reply #30 of 48)

by calvin in reply to doormatt [original] on Tue, 12/27/2011 - 17:29

Did you install a pan or fab one up with a vicor type product?   On the slab, with a lip at the backside and run up both ends of the framed opening?  There's a flexible product (or two) that you can form up and around giving you a one pc seal.  I've only done it with pcs, overlapping as I go.

Something that gets in will not get stopped at the bottom corners.  All the caulking in the world under the threshold will not stop the water from going sideways-easily to your wet points.

Take some paper towel or whatever.............

cram it in from the inside - down at the bottom corners.

Go outside and spray just at the bottom-slab/wall joint.

Check that paper after an hour.

Put another couple pcs in the corners from the inside.

Flood the area a little higher.

 

Work your way up-giving at least a hour to let the water work it's way in and down.

 

I found a slab wall leak after a whole lotta trying, at the bottom of some brick on slab veneer.  It took easily an hour for it to work its way inside.  The gap was UNDER the brick, in the bed joint of mortar------------couldn't see it if you stood on your head.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


http://www.quittintime.com/

 

Home › Forums › Breaktime › Construction Techniques