Waterproofing outside of poured concrete basement walls

[BruceWard]

I have 870 square feet (87' x 10') of 8" thick poured concrete walls that I want to apply waterproofing to before backfilling. The slab has up to 8" of gravel underneath it and has two large french drains. There is gravel underneath the footers as well. When I back fill there will be 1' to 2' of gravel outside of the walls. I believe it is unlikely that any water will build up outside the walls as it can flow down through the gravel escaping either around or under the slab.

Initially I was planning to use this stuff SONOSHIELD HLM 5000 ROLLER GRADE WATERPROOFING (5G)

Today at Lowes I noticed they sold DRYLOK with a 10 year warranty for half the cost Shop DRYLOK 5 Gallons DRYLOK Latex-Base Masonry Waterproofer, White at Lowes.com

I have heard about peel and stick solutions.

I also have enough 6 mil plastic left to cover the outside of the wall perhaps providing some protection during backfilling.

I would appreciate recommendations for products you have used?

These are the walls

Thanks

 

[bdw593]

Just built my house last fall and went through the same thing. The drylock dries and stiffens up and will not "move" with the concrete and will crack.. I used a waterproofing in a five gallon bucket that was the consistency of tar. Put one of those heavy duty gloves on and smeared it on to grade. The waterproofing is made for below grade and will provide flex. One thing about concrete it will crack nomatter how good your contractor is, most of these are just surface cracks. The tar waterproofing will flex with these cracks will allow these cracks to be covered and less chance of moisture problems. You did well with the gravel. Drainage is the key. I'm no expert but thats what I learned through my building process. I'm wanting to say the 5gal bucket was round $65.00 for good stuff and round $45-50.00 for offbrand stuff.

 

[dstig1]

+1 - what BDW said. You want something that remains flexible, and a liquid applied product is best as it will be continuous. Mostly this is considered "Damp proofing" rather than water proofing as you already appear to know - the proper fill and external drainage is what deals with bulk water. The coating is mainly to prevent moisture migration, and as an added barrier to encourage the water to head south to the footing drain rather than wick into the wall. Remember concrete is porous and will wick water quite effectively. The damp proofing is essentially a capillary break to stop that. You don't want to skip this, or use an improper material. Getting access later on to fix an issue will be very expensive and you will kick yourself if it becomes a problem.

Treat the entire wall and the exposed part of the footing. And break off those form snap ties first so you have a uniform surface that will get sealed. Working around those will be a PITA too.

If you want to be extra picky you can add a protective layer over the dampproofing to help protect it from backfilling damage. There are products made for this that come in roll or sheet form. There are whole systems that combine a coating and protective layer. Tuff n Dri/Warm N Dri is one example.

The Sonoshield you posted looks like it fits the bill.

 

[JB4310]

The proper term is damp proofing, an asphalt based material, could be sprayed, rolled or brushed on. No surface applied material will guarantee a waterproof foundation. Drylock is nothing better than the typical asphalt coatings. I would get the material from an industrial supply instead of a home center, should be a better quality.

Crushed stone under the slab is a good idea, crushed stone under footing is not. Typically you want to hold all the water you can back with the foundation, then have a drainage system under the floor along the footing to collect what makes its way under.

Before you backfill run a perforated pipe along footing, not higher than the top of the footing, have it discharge to the surface, of course maintaining grade or a little pitch to the end.

Instead of or along with foundation coating you could use a geotextile foundation sheet drain system, but it cost about .50 PSF. that would leave an air gap between foundation and fill, zero hydrostatic pressure, any water that gets in drops to bottom and footing drain.

Foundation coating and footing drains are usually enough. if that space is going to be finished living area, then you might seriously consider the sheet drainage.
I use this company's products.
Prefabricated Drainage Systems - Roof Drainage Products, Yard Drainage Solutions | American Wick Drain

http://www.americanwick.com/uploads/documents/Installation%20Instructions%20-%20Basement%20Wall.pdf

I don't do new construction, but do basement waterproofing work on existing structures.

EDIT: I repeated alot of what Dave already said cause I'm a slow typer and didn't see his response.

Good luck, JB

 

[boggen]

the tie rods, for the forms. are going to be leak points.

i honestly don't care much for dry lock. yes it works. and you will be putting it on the outside of the wall were water pressure will be pushing it against the concrete.

but drylock flexing. it is not the best.

if it were me, i would get "roofing liner" used for flat roofs on buildings, were they put tar down and then a rock layer over it. half the time the stuff has some sort of chemicals applied to it, that it can not be used as a pond liner, example 45 mil firestone pond liner. but the roofing liner is cheaper than pond liner.

roofing liner has more flex within it, not purely like a rubber band but alot more than drylock. and just put a single layer of it around your basement. you could use tack strips with some concrete anchors to temporarly hold it in place till you back fill around the basement.

==================

6mil plastic, does not hold up, been there done that.

some folks have used hot tar and a good size big brush and just smeared the tar onto the walls.

===================
as far as back filling, think "french drain" around entire perimeter of the basement footers. french drains are either 3" or 4" pipe with holes in it with a mesh over the pipe. ((normally called a sock mesh over the pipe))

french drains, also use rock around, above the pipe. to help funnel water down into the pipe. and once rock is on some more fabric is placed on top of the rock. to keep dirt from clogging up the rocks and pipe.

====================

there are many ways to waterproof the basement. if you asked for "xprex" or water proofing additive to the concrete before it was poured, you could of been in better shape, with exception of the tie rods for the concrete forms that were used.

 

[BruceWard]

Drylock is out. I am going to shop around and see if I can find an asphalt product or something like Damp Proofing | Henry.com on Monday.

Unfortunately concrete supplies in my local area are monopolized by Darragh Company Home Page . Their location 40 miles away will sell HLM 5000 for about $1 a square foot. The local office does not want to sell materials, they want to provide a service for $2.50 a square foot. I am hoping I can find an apshalt product at a roofing company.

 

[greasemonkeyok]

Not necessarily endorsing their specific products, but Tremco sells various products on a commercial level. Good place to learn what is available.

Below-Grade Waterproofing Membranes - Tremco Commercial Sealants & Weatherproofing

 

[dstig1]

It will be possible to buy this stuff online, I bet. Not the easiest to ship, but not the worst either. You really should be able to find similar products at good lumber yards in your area. Or they should be able to get it for you in a reasonable time. Ask around. It shouldn't have to come from a concrete place.

I also noted that the Sonoshield you posted about initially recommneds/requires the use of a protective board below grade. They showed the protective material at the bottom of the page.

 

[nealfris]

In my area, code dictates, and waterproofing must be inspected. Snap ties removed, mortar applied over tie holes, asphalt coating applied. That's code here.
What I did back in 1982 when I built my house, was purchase a product that was similar to the Henry 787 elastometric coating. It was like very thick rubberized asphalt. Make certain you covered up from head to toe, including throw away shoes. I used several 9" rollers. A helper would be a huge help. Slopped it on thick! Rolling in all directions, making sure there is NO air holes what so ever. When I was done, I backed out of the hole stripping off all the Tyvek suit and such and left it in the hole, other wise you will own it for weeks. Oh ya, snap lines at grade. You go above grade at all, it never comes off.
My back fill was all clay. Not a drop through the wall in all these years. I did have a problem with window wells overflowing in to the cellar that I had to deal with. If you have the plastic, I would not hesitate to use it as protection for the coating as well as extra water diverting. If you put it on before the coating sets up, plastic should stick right on.
I would find the supplier you always see go by with the huge trucks loaded to the sky with whole house frames worth of lumber. They will carry all the products the pro's use at the best price around.
I was looking at your pictures. Is it an optical illusion or is that blazer parked way to close to the hole??? Around my parts we always pour 10" thick foundations and never back fill until the deck is framed and bolted for cave-in safety.
Sorry to be so long winded!

 

[BruceWard]

The Blazer looks close but he has to be at least 20' away.

Here is a picture before the slab was poured that shows the slope in that area.

The snap ties are removed but the holes around them are not filled.

I have an area of red clay where I have considered buiding a pond and using the clay for back fill. If I did I would still use gravel a foot or two out from the house using the clay to fill the rest of the hole. The current plan is to use city pit to back fill as it is the cheapest material I can get.