|Brett M. Wilbur AIA, CDT|
Post Number: 48
|Posted on Thursday, June 23, 2005 - 04:48 pm: |
I'm looking for an exterior finish coating for concrete tilt-up panels. The project I am referring to is an expansion of an existing tilt-up facility near Houston. It's an infill of two bays of a covered maintenance garage and an interior expansion of their existing offices. I suggested skim coating masonry, but they did not want to go in that direction. They also don't want to paint the entire building, so the two new panels will be painted to match a somewhat deteriorated and faded original finish.
I'm looking at a silicone-modified elastomeric. It has 700 percent elongation, and can be color tinted. I've read in another thread that it may attract dirt though. Another option is an acrylic emulsion. The literature states that it is internally plasticized, so it should not become brittle after many years of exposure. Both products are breathable and can be applied to "green" concrete.
I don't think I need to go with Tex-Cote, seems overkill for what we are doing, and I don't need a texture. I need coating with crack-bridging capabilities, weatherproofing, breathability, durability, tintability. Would a high-performance paint work?
Anyone have any other options or comments?
|William C. Pegues, FCSI, CCS|
Post Number: 405
|Posted on Thursday, June 23, 2005 - 05:12 pm: |
Textured Coatings of America makes a whole series of coatings that begin with the Tex-Cote prefix followed by numbers. And in each coating they range from very coarse coatings to no texture at all. So, don't let the Texture in their name mislead you.
Their rep should be able to steer you in the right direction for what you need.
You might also consider Series 156 Enviro-Crete, Tnemec Co., Inc. which is a smooth finish coating.
Both systems come with their own primer requirements.
The interesting thing abouot some of the Textured Coatings of America coatings is that many of them have a high build primer which is capable of hiding some imperfections in the concrete surface.
Tenemec has many other coatings that might apply as well.
Post Number: 18
|Posted on Friday, June 24, 2005 - 02:10 pm: |
Be aware that any silicone modified or silicone coating has a low gloss appearance when viewed from any side angle. Remember that elastomerics have lower tensile values. I would suggest you look at a flat low film acylic coating like Chemrex-Thorosheen. This product can be custom matched to your color of choice. I would also recommend you pressure wash the exisisting surfaces before the color match. I hope this helps.......
Post Number: 115
|Posted on Monday, June 27, 2005 - 03:49 pm: |
I'd be selective about applications of siliconized coatings. In addition to the dirt pickup problem (a midrise building across the street is being recoated as we speak, following litigation) there's also the issue of compatibility of future recoating applications - silicone is slippery stuff.
Elongation shouldn't be an issue in concrete tilt-up construction - it doesn't move much.
|Don Harris CSI, CCS, CCCA, AIA|
Post Number: 41
|Posted on Monday, June 27, 2005 - 04:24 pm: |
We've used Tex-Cote and Thorocoat, both smooth and textured, sucessfully in a number of projects. Our one problem was with an elastomeric. It bubbled because the contractor painted the panels too quickly and the vapor had nowhere to go. This is probably a common issue seeing how quickly things go up in the field now a days.