coating concrete

[Hamilton Audio]

I've got a trough drain in front of my garage (inward sloping driveway makes it a river in rainstorms). I recently rebuilt the trough and all the concrete around it, using treated plywood as the form (due to limitations, the form had to stay installed).

I coated the entire inside and railing with rubberized spray undercoat, thinking it would work great. it did, for about a month. In cleaning the drain out (it acts as a nice trap for dirt and crud before it drains), I was pulling up the undercoat too :-( So I'm looking to seal the concrete inside the trough with something tougher as it holds water a lot of the time (which will lead to concrete failure prematurely I'm sure).

I've got a "plastic based" sealer that is VERY thick....it resembles a thick tar substance both in smell and look, and is VERY sticky. I'm debating buying a larger container of this stuff and slathering it inside the trough. I've used it to seal my foundation when I noticed some cracked parging, and it is seriously tough. not easy to work with, but tough.

is there something more appropriate for this application? I guess any goo I can lay on the cement that will keep the water off it will work, won't it?

bmoney

[Robert Allison]

You don't need to protect concrete from water. Water won't damage it. Go look at any retention pond at any large parking complex and you will see what I mean.

[Joseph Meehan]

While I really wonder why the plywood needed to stay in place, if it must, I suggest fiberglassing it.

[Hamilton Audio]

I actually used 2x6 treated boards. the form created my channel, and the rail/grate sysytem sat right on top. the rail/grate has nice 1" wide "straps" that spread out into the fresh concrete, holding the system in place.

so, with the rail/grate on top, fresh concrete all around, I could not think of any other way to do it but leave it in place.

bm>> I've got a trough drain in front of my garage (inward sloping driveway >> makes

[Hamilton Audio]

hmmm....why do we have products for sealing concrete from water if water doesn't affect it? I'm told that concrete (being porous) will absorb a good amount of water, and when it gets real cold out, this water freezes, splitting the concrete.

in this light, and since I live where there's more winter than summer, you can see why I don't want water being absorbed? or is this all myth?

[Robert Allison]

While I don't claim to be an expert on the frozen north (you can see I live in Texas), I believe that most freeze related damage to concrete occurs from frost heave. This occurs due to the moisture in the soil around and under the concrete rather than in the concrete itself.

As I said, I am no expert on frost heave. If there are tundra experts out there that can correct my information if it is incorrect, I look forward to hearing from them.

[raven]

Why do we have people selling snake oil is snakes don't squeak?

That's why highways accorss the country avoid the use of concrete exclusively, or pay huge bills to spread Thompson's water seal on it annually. Hmm, wait a moment, they don't.

The latter. Concrete is porus to be sure. That water can and does freeze but that only damages poor concrete.

John