Painting a Retaining Wall

[JAE]

Any thoughts on the wisdom of applying a paint or stain to a concrete retaining wall? I've been looking into doing this on a large (16' high) wall but have been concerned about the potential for moisture coming from the ground behind the wall and getting trapped inside the concrete. This is in a freeze/thaw area.

 

[cvg]

I have tried staining with poor success. The end result was a very mottled appearance and was rejected by the owner. The wall was painted, but is not retaining earth - so no experience with the water issue.

 

[DaveVikingPE]

I looked at a concrete retaining wall (11 ft high at highest, I think) last week in New Jersey that had an anti-graffiti coating that looked pretty solid, that is, I saw no evidence of moisture penetration/damage, etc.

 

[jimaitken]

As far as concerns abour moisture are concerned have you looked into integral capillary concrete waterproofing systems? A company called Penetron did a presentation for me a few months ago. This system apparently is drawn into the capillary structure of the existing concrete and seals it from the outside - in, and does not have to be applied on both sides to be effective. It can be used on existing concrete surfaces as well as in an admixture for new concrete.

If you can seal the concrete you may be able to paint it without worrying about the moisture issue.

 

[JAE]

Thanks for the replies so far. I forgot to mention that the earth side of the wall would have a drainboard with filter fabric on it. So there technically would be moisture applied to the earth side of the wall over its life.

The owner is interested in the paint/stain only for aesthetic reasons, not for waterproofing. There is a large overpass bridge structure nearby and they are using some sort of penetrating/sealer stain and they liked the look of the girders. The girders are precast prestressed bridge girders with in-plant formed surfaces so the quality is nice. For a field formed retaining wall I'd wonder about the mottling that cvg mentions.

 

[jimaitken]

Here is the link to the product I mentioned.

http://www.penetron.com/

 

[HgTX]

TxDOT stains and/or paints a lot of retaining wall. Not much freeze-thaw, but moisture issues might be similar.

There's a contact number on this page:

ftp://ftp.dot.state.tx.us/pub/txdot-info/cmd/mpl/surffnsh.pdf

Hg

Eng-Tips policies: faq731-376

 

[SlideRuleEra]

As a bridge contractor, we used Acryl 60 (on HgTX's list) mixed the "Thoroseal". That is the pearl gray color that many bridges have. A product called "Thorocoat" can then be applied over the Thoroseal for a wider range of colors. Should be suitable for a retaining wall, too.

http://www.ruberoid.ie/ruberoid31.htm

and

http://www.chargar.com/Products/prod_ma.html

http://www.SlideRuleEra.net

 

[Ron]

JAE...assuming the concrete is air-entrained, I would not worry about the coating. The amount of moisture that gets into the concrete through interstitial diffusion and capillarity does not typically present a freeze-thaw issue, since the pore structure expansion is absorbed by the entrained air voids.

 

[dik]

As a followup to Ron, you should be able to use an acryllic latex on concrete... check with the manufacturer... not an oil base... else you might have a 'soap' layer. If you have water buildup on the soil side, you likely have worse problems with freezing that a little exfoliation...

Dik