Author |
Message |
Mounir Kronful (Unregistered Guest)
Unregistered guest
| Posted on Wednesday, July 04, 2012 - 09:02 am: | |
I have always known that it is not recommended to use epoxy traffic coating over a suspended slab since it will crack. Is this correct? where can I find any information about this issue. regards Mounir |
John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick
Post Number: 1415 Registered: 03-2002
| Posted on Wednesday, July 04, 2012 - 04:28 pm: | |
I'm not sure that's true. I have used urethane traffic coatings occasionaly, many of which have epoxy primer or intermediate coats. Epoxy formulations vary widely, and it is not necessarily the case that they lack flexibility. I would talk to your local reps for good input, as local trade practice can play a role in selection. 4specs.com has manufacturer listings under 071800. |
Mark Gilligan SE, Senior Member Username: mark_gilligan
Post Number: 485 Registered: 10-2007
| Posted on Thursday, July 05, 2012 - 12:17 am: | |
I do not know why this is not recommended but will make a couple of observations regarding concrete. There is a truism that concrete cracks. The question is how much and how big are the cracks. Mild reinforcement and post tensioning can be very effective in controling cracking in concrete. |
Jeffrey Wilson CSI CCS Senior Member Username: wilsonconsulting
Post Number: 74 Registered: 03-2006
| Posted on Thursday, July 05, 2012 - 09:53 am: | |
I don't believe the statement is true. If you're referring to true traffic coatings, this product type is specifically formulated for use in parking structures & on roof decks. If you mean epoxy-based resinous flooring systems (which are frequently referred to as "traffic coatings") these are also routinely applied to suspended slabs. Manufacturers typically require that control joints in the flooring system align w/ those in the slab. This practice should avoid cracks in the floor topping. |
J. Peter Jordan Senior Member Username: jpjordan
Post Number: 462 Registered: 05-2004
| Posted on Thursday, July 05, 2012 - 10:31 am: | |
Since traffic coatings are typically used on parking garages, and since almost all of these applicatons are suspended slabs (except the bottom floor which may not get a traffic coating), and since traffic coatings are offered in epoxy, urethane, and various combinations; I would very much assume that product offered as traffic coatings, regardless of formulation, whould be suitable for suspended slabs. |
Richard L Matteo, AIA, CSI, CCS Senior Member Username: rlmat
Post Number: 513 Registered: 10-2003
| Posted on Thursday, July 05, 2012 - 11:20 am: | |
I would look at manufacturers data from someone like Pacific Polymers, div. ITW, or Dex-O-Tex for traffic coatings, and General Polymers, div. Sherwin-Williams for resinous/terazzo coverings. |
Richard Hird PE (Unregistered Guest) Unregistered guest
| Posted on Thursday, July 05, 2012 - 01:55 pm: | |
Perhaps the concern is based on someone's expectation that the traffic coating is an effective waterproofing material. Since epoxy is not elastic, it is not going to bridge cracks. It also requires near perfect bond, so poor surface preparation will cause delaminations. Both of these problems lead to leaks. Without considering what the use is below the slab it is hard to say if it is appropriate. |
ken hercenberg Senior Member Username: khercenberg
Post Number: 294 Registered: 12-2006
| Posted on Thursday, July 05, 2012 - 02:56 pm: | |
This is actually more of a problem than many people realize. Traffic deck coatings fail a lot more often than we'd like. It's why restoration companies stay in business and why warranties exclude cracks that form in the substrate after application of the membrane. Whether 'traffic coating' or 'resinous flooring,' the problems can be similar. Often resinous flooring systems are applied in conditioned spaces that are smaller than parking decks so cracking is less pronounced. Still there are numerous incidents of failure, especially when transitioning between rooms, extending finishes down long corridors, etc. Many people have moved away from vapor impermeable epoxy and urethane traffic coating systems, opting instead for vapor permeable acrylic-based coatings. Some of these coatings have excellent track records. For the most part, if coating/flooring installation can wait to let the concrete dry, shrink, and crack, then at least the cracks can be treated and crack suppression membranes installed. If the installation is one that matters to you, specify crack suppression membranes or flexible base coats prior to installation of the coating. This is why we specify divider strips in terrazzo, to control where the cracks will occur. |