Dear brother carps and contractors,
This is my first post although I’ve been visiting for 8 years. I’ve been in construction since 59 and a carp since 66. Last 20 years mostly residential remodeling although I occasionally do new houses. 2 years ago I remodeled a bath for a local businessman and he’s been keeping me busy since.
I’m currently in the process of installing a pool completelly enclosed by a concrete retaining wall. The wall is approx 8′ high on the uphill side and 3′ high on the downhill side . The owner formed it up with some old simplex forms which he borrowed from his concrete finisher contractor. I think the finisher must have bought them at auction because they’re the roughest looking forms I’ve ever seen and the resulting concrete wall reflects the same. I’ve been working for this owner for almost 2 years and he thinks I can make anything look good, so I don’t want to disappoint him. His idea is to cover the outside of the wall, where exposed to public view with imitation fake stone and the pool side of the walls with a parge coat of cement making it look like old stucco. The stone will be subbed out to a brick mason so I’m not to concerned about it , but I’ll be doing the inside parge coat. He wants me to make it look like the concrete block foundation wall which I parged with just regular mortar on an addition I built for him a couple of years ago.
My thoughts are to power wash, grind the form seams and parge with a coat of 50/50 portland cement/sand with some kind of additive. Possibly also using a bonding agent like Thorobond. Lately I’ve been using Vinyl Patch for any concrete rub out, but I don’t think it will give me the look I want. Give me your thoughts if you’ve done something like this.
Thanks, Ron
Replies
I have parged with sand:cement at 3:1, Stucco color coat, Tile grout, and colored sand/cement.
Any mix richer than 3:1 is going to work. You can add 1/4 to 1/2 part lime to make it a little more workable.
Even on 25 yo 'crete, all I did was pressure wash. On every job, I misted the wall first and applied the mix as soon as the wall was surface dry. Usually wetting the wall section just ahead of the one I was going to work was fine.
If you use an adhesive admix, don't use much, 10% - 15% as much as water.
No matter what you do, those ridges are going to bleed thru.
If the wall has bee holes, pack them first with plain sand/cement using a black rubber sponge.
The most critical parts are using the same recipe for every batch and finding a texture you can apply consistantly.
Decorative ideas:
1)Acid stain the wall one color.
2)Acid stain the ridges a contrasting color
3)Knockdown splatter texture the wall. This will kinda hide the ridges.
4)Color coat and splatter in complementary colors. Very hidey.
5)Skip trowel texture. Hides everything.
6)#5 with different colors.
If you do 1 or 2 and don't like it, you can still do any of the others on top.
SamT
That's good advice Sam !
I'd offer another alternative for a finish coat.....
Do the prep and basecoat with a 3:1 mix, using Sam's method's
and steel trowel smooth.
Finish will be acrylic stucco using a small drywall hopper gun.
You will have to prime your basecoat and keep a wet edge, but your
ridges will be hidden and your color uniform.
Fine sand finish shoots best, no need for any hand trowelling. Fast to apply.