Question about waterproofing (slightly) below grade wall

[Onewolf]

One side of the garage slab for our detached garage build will be slightly below (6"-12") grade. Our GC just provided us a estimate/quote to waterproof this area (~200 sq ft). His estimate is:

Material cost for 200 sqft 1 $900.00 $900.00

Dig the rest of dirt away from footer so we can lap outside edge along the right side of garage wall and wood shop wall. Also the left side of the entry door to garage.
Pressure clean block stem wall and footer. Patch any holes in stem wall.
Come back next day so block can dry.
Wipe area with clean with xylene before applying Tremproof 250
Apply one coat of primer let get tacky then apply one coat 60 mil of Tremproof 250 GC roller grade.
Install tremco protection mat over all water proof areas

200 $10.25 $2,050.00

Total = $2950

:

I was shocked at this estimate. It seems to me (ignorant) to be extremely high.

The primary wall in question has a footer/foundation, 2-3 courses of CMU block stem wall (solid pour concrete) and then 10' CMU block wall.

I can buy two five gallon buckets of DryLok Extreme from Lowes for $260 which would be enough to apply at least 4-5 coats of drylok. I have already dug out the wall down to the foundation, cleaned it, and patched all cracks/voids/holes with Drylok Fast Plug.

What say the experts? Is $2950 too much for professionals to install 200 sq ft of Tremproof 250 and protection mat?

Would 4-5 coats of Drylok extreme applied by me be a reasonable alternative?

Thanks!

 

[pstnbly]

I've made a living out of damp proofing foundations. Grab a shovel, dig out around the foundation. allow it to air dry, wire brush loose material away, if it doesn't have asphalt on it dampen and Drylock 2 coats, if it does have asphalt or after Drylock apply trowel consistency roofing cement to grade, apply 6mil poly sheet, backfill. I can't imagine spending more than $300.00 and a couple days to do it. Contractor threw a price for the hassle.

 

[Onewolf]

Thanks for the reply/information. The wall will be stuccoed after waterproofing.

apply 6mil poly sheet, backfill.

How do you 'apply' the 6mil poly sheet?

 

[pstnbly]

Cut the width you need and stick it to the tar.

 

[Concrete Homes]

I did this in Minnesota. Had to did down the width of a shovel around foundation and dug out the footing as well. Pressure washed the Leaky CMU block, let it dry and applied Sonneborn HLM 5000, trowel grade. Covered with protection board, (I would use Eco-Drain Mat now) and did a 5" French drain around the footings, which I daylighted out to a lower grade. Be sure to backfill with a clean 3/8 pea gravel that will allow drainage. You might also look at Henry's Peel and Stick membrane, but be sure to lap it over your footing.

 

[Cyberbear]

In the old days they'd spray hot tar over the porous base material before covering with a water proof membrane. Today's cold sealer is probably just as good when installed properly.