Foundation Waterproofing - InspectionNews

Greg Jenkins · #1 (**permalink**) 06-07-2008, 02:35 PM

Do we have any experts on Foundation Drainage Panels. In the posted picture you will see what I think is a dimpled geomat waterpoofing system for the below grade foundation walls.
Should this material have been cut evenly with the top of the foundation wall and sealed? Is there a chance of water getting behind it in its current condition?
This is new construction. The house was just recently completed.

Jon Randolph · #2 (**permalink**) 06-07-2008, 03:32 PM

I have never seen this material and know nothing about it so there is little or actually no experience behind the following statement.

It seems to me that it was installed backwards. I would think that you would want the groved side facing the foundation to create a channel for any water to run down and into the perimeter drainage system. The channels, as this is installed, are plugged with dirt and mulch so I don't see how it would be any better than a water proof sheeting.

Victor DaGraca · #3 (**permalink**) 06-07-2008, 04:21 PM

Bingo, Jon....

" its stud-shaped dimples provide an air chamber between the roll and wall, keeping walls dry. The dimples are aligned along vertical and horizontal axis to rapidly channel water from grade to the footer drainage system"

Mar-Flex: Geo-Mat Products

Victor DaGraca · #4 (**permalink**) 06-07-2008, 04:29 PM

Oops...spoke too soon....
then there's this product....
http://http://www.amvic-pacific.com/...0Basements.pdf

http://www.amvic-pacific.com/Downloa...0Basements.pdf

"After application of either an approved waterproofing membrane or a liquid waterproofing compound, unroll

the Protecto Drain 2000-V and place against the surface with the flat side of the panel facing the wall"

http://www.amvic-pacific.com/Downloa...rain-2000V.pdf

So.... Greg, not having x-ray vision, I can't comment on what's below grade. However, what is visible, appears to be improperly terminated, and looks like it will allow water to run behind the dimple board, defeating it's purpose.

Jerry McCarthy · #5 (**permalink**) 06-07-2008, 06:29 PM

Greg, not the same material, but similar and properly attached.
Had a law suit where it was not and a case I lost as the EW for a large GC. They paid over 350K for water damage.

Jon Randolph · #6 (**permalink**) 06-07-2008, 06:52 PM

Quote:

Originally Posted by Jerry McCarthy

not the same material, but similar and properly attached.

Jerry,

I'm not interrogating you as I have no experience with it, but it seems wrong. Are you saying that the material in Greg's picture above IS installed correctly?

Jerry Peck · #7 (**permalink**) 06-07-2008, 07:10 PM

The *other* Jerry here ... *to me* it looks like the material in the photo is not applied correctly. WC Jerry was showing a different product in his photo.

This is from the Geo-Mat web site: (underlining is mine)

"Mar-flex Geo-Mat Products are designed for various applications. Geo-Mat is a dampproofing drainage roll, Geo-Mat Plus is a protection and drainage roll used in conjunction with Mar-flex’s waterproofing membranes to form a complete system, and Mar-flex Geo-Mat accessories are used to professionally complete any job."

"In conjunction with ... waterproofing membranes"

Was there a waterproofing membrane applied?

Tom Edwards · #8 (**permalink**) 06-08-2008, 08:01 AM

I installed this material on my new home 4 years ago.
Victor's explanation of how it is to be installed with the silt screen on the outside and the dimples against the wall is correct.
The mat only helps channel water to the drainage system. Otherwise, it does nothing for water proofing a wall. It should be installed with an adhesive.
The builder wasted a lot of money on installing the mat "wrong side out".
I would report this to my client and recommend correction, as costly as that may be. In addition, if the builder got this wrong what else did he miss?
I think this materal works very well when correctly installed. You can place this over any other coatings you have applied.
Another dumb builder story.

Jerry Peck · #9 (**permalink**) 06-08-2008, 09:20 AM

Quote:

Originally Posted by Tom Edwards

place this over any other coatings you have applied.

That was the manufacturer's point I was raising - that this material is a "drainage plane", not "waterproofing". It needs to be applied over "waterproofing".

Greg Jenkins · #10 (**permalink**) 06-08-2008, 10:06 AM

Here is another picture of the same house but at a different location along the foundation wall.
Since I was not familiar with this product I did not know what to look for at the time of the inspeciton. Now I am looking at this second picture and I can not tell which side the dimples are on.
Can any of your trained eyes figure it out?

Greg Jenkins · #11 (**permalink**) 06-08-2008, 10:08 AM

Also, it looks like there is fabric between the mat and the soil.

Jerry Peck · #12 (**permalink**) 06-08-2008, 12:58 PM

Greg,

That photo shows a different product, however, the intent would be the same.

The top show be closed off, though.

The purpose is to create drainage channels for water which seeps/weeps through the soil to gravity drain down to the drainage channel at the bottom.

Allowing more water in at the top (with the top being left open) only adds more water to the drainage system which must then be drained away.

Greg Jenkins · #13 (**permalink**) 06-08-2008, 02:10 PM

So, In summary: The pictures are of two different drainage plane products. Both appear to be improperly terminated or sealed at the top. One (the first picture) may possibly be improperly installed with the dimples facing the wrong directions. Of course, all of this is assuming these are not just scrap pieces left behind during backfill.
It sounds like my client should request some excavation for further investigation as well as some product information and assurance from the builder that these products are installed properly.
Thanks for all the input.

Jerry Peck · #14 (**permalink**) 06-08-2008, 03:49 PM

From what I can see in the photos:

Quote:

Originally Posted by Greg Jenkins

So, In summary: The pictures are of two different drainage plane products.

Yes, they look like different products in the photos.

Quote:

Both appear to be improperly terminated or sealed at the top.

Yes, from what I can see.

Quote:

One (the first picture) may possibly be improperly installed with the dimples facing the wrong directions.

Yes.

Quote:

Of course, all of this is assuming these are not just scrap pieces left behind during backfill.

Correct.

Quote:

It sounds like my client should request some excavation for further investigation as well as some product information and assurance from the builder that these products are installed properly.

Agreed.

Markus Keller · #15 (**permalink**) 06-09-2008, 07:30 AM

The material shown in the pictures looks like the stuff typically used around here when installing a 'french drain' tied to a sump pit.
Installation looks sloppy. I find it doubtful that that material as shown could act as a 'waterproofing' membrane.
Just my thoughts.