Need advise from a concrete professional

[Jim Stanley]

New home purchased October 2014. Very poor concrete finish on the three car garage floor. Builder agreed to diamond grind and coat with "Ardex". The results appeared acceptable. Summer of 2015 noted floor displayed indentations from anything that may have rolled over it and you could easily remove topcoat with a scrap of soft pine. Ardex company agreed to send a rep to sample the product and determine the cause of failure. Samples were sent to their lab and it was determined the contractor used the wrong product (Ardex Feather Finish).
After several months of "discussions" with the builder, it is now agreed that the garage contents will be moved to temporary storage, diamond grind the floor to remove the failed and/or improper topcoat and again resurface.
The contractor wants to epoxy the floor stating it will last for years. It has been noted by others that Ardex SD/M will provide a more durable and permanent floor.
To say the least, I am "very" upset over the situation and really not looking forward to having to move my entire shop and then later setup, level and recalibrate all the equipment not to mention loss of shop production during repairs.
The question is which will be the best coating for the floor? I am not as concerned over appearance as durability and safety are a priority. I don't want to face the possibility of another repair or recoat in 5 or more years. I am retired and work in the shop on a daily basis. Any advise would be most appreciated.
Thanks, Jim

[Peter Aeschliman]

Jim,

My $.02 as a non-professional: If aesthetics are not a concern, I would recommend a penetrating sealer, such as a siliconate product. It penetrates and has a chemical reaction with the concrete, sealing it and creating a better wear surface. The concrete will look unfinished, but will be a durable non-slip surface.

I researched this topic until I was blue in the face. Lots of contradictory information out there. I bought this product for my basement, but I have yet to use it:

http://www.concretesealersusa.com/cc...1g-ps1011g.htm

They claim that it provides a great base for epoxy (and that they designed it for that very purpose)... but I couldn't get any epoxy manufacturers to agree with them on that, and couldn't get Concrete Sealers USA to recommend any specific epoxies. Everybody in the concrete floor sealer business seems to be very concerned about warranty claims... That alone should tell you something!

That said, maybe you just do nothing. I agree that taking apart your shop and then redoing it would be a monumental hassle. If the current sealer's failure is only an aesthetic issue, and not one of safety or durability (which you said are your primary concerns), maybe you just ask the concrete guy to pay you an agreed upon settlement and just live with it.

[Mike Heidrick]

Head over to the garagejournal forums - tons of awesome concrete research and experiences there. There are some military grade epoxy coatings from legacy I believe that look amazing!!! Id go full solids epoxy!

[Ole Anderson]

I would diamond grind and leave it giving it that terrazzo look. Maybe apply a concrete stain? Any coating has the potential for failure. I know. I am a civil engineer (not unfamiliar with concrete) and when I had my old garage floor removed and re-poured, I had them add a brick color pigment which was cool and a sealer. Well, the sealer they used was not impervious to solvents, like brake fluid and gasoline. Duh. A month after I did my floor I was out of town and lent my garage to my neighbor and good friend in the dead of winter (it is heated) so his buddy could do a brake job. I came home to a black stained mess where he got brake dust all over the floor then spilled brake fluid on it. I am seriously thinking of just getting a diamond grind to remove the whole mess.

[Jim Andrew]

When concrete is ground down and finish applied, looks a lot like marble.

[Jim Stanley]

Thanks for the suggestions, recommendations. I would be fine with a stain and/or sealer over the diamond grind. The concern we have is what may be under the topcoat now on the floor. If I remember the new floor displayed "spider cracks" or "crazing" which I was told were the result of rapid evaporation of water in the concrete. The reason the newly poured concrete had to be diamond ground and top coated was due to "poor" workmanship. If when the floor is ground and the concrete appears to be in decent shape then stain and seal will be the answer. If there are other concerns that may be revealed, I want to have a back-up plan in place, i.e.- durable concrete topcoat or a durable export.
Thanks,
Jim

[Marty Tippin]

If there are cracks and settling that pose a trip hazard, I don't imagine there's anything you can do to the surface that's going to stop that from continuing. And if it's purely about cosmetic appearance, I can think of a thousand things that would be higher priority in my world...

[Morey St. Denis]

Congratulations! You've experienced intent to commit fraud by GC management, workmen, or a specialist subcontractor... Concerns over applying an appropriate surface finish should likely be among the least of your concerns at present. Suggest you get some recorded proof that the slab subsoil and then again the gravel base was properly compacted prior to the pour. Was a polyethylene or other vapor barrier applied over the gravel? How much steel rebar, reinforcing mesh and "hardware cloth" actually went into the form before that pour? These crucial tasks may all get conveniently hidden and the financial incentive to cheat is just too great for most to resist. The people doing this work generally have little to no technical education in the field. Basic failure to grasp that stoichiometrically mixed concrete can be very strong in compression while disappointingly weak under the slightest of tensile loads. Any rigid structure subjected to bending or other deformation forces experiences both tensile and compressive loading at extreme surfaces. You said yourself: "Not as concerned over appearance as durability and safety are a priority".

A substantial quantity of steel cross-section must be imbedded as close as practicable to those surfaces bearing tensile loading. Most any concrete ''professional" who cared about the quality of their work readily knows how to avoid those surface cracks and spalling that bear witness to excessive heat or evaporation during the curing phase, provided said concrete was properly mixed at the outset... Suggest you first concern yourself with the validity of the underlying substructure before splitting hairs over a portland based vs. epoxy w/solids aeshetic surface coating.

I'm amazed that you apparently still have some leverage over that contractor to make them come back and make things look better!..

[Richard Shaefer]

stop being such an Engineer with a capital "E"!

by the time someone came out to core the slab, test the core, stick a nuclear soil density meter down the hole, and run a pachometer over the slab looking for rebar, it's be cheaper to rip up the slab and replace it.

and you even used practicable in a sentence! Shivers, dude, shivers!

Sika makes some good silane products meant for bridge decks. If it holds up for 10 years on a bridge deck, it'll hold up longer than you have left on this earth in your garage.
They have on-staff product support that is knowledgable and helpful.
I suggest you call them, tell them what you want to achieve, and they'll recommend a product.

I don't think Texas is a low VOC state, but ask. they'll know.

[Jim Stanley]

Update- Based on input from fellow creekers and some extensive research and discussions with the contractor, we have agreed to a polished concrete floor. It should prove to be a permanent solution to the problem and provide a safe, durable surface with little if any maintenance over the years. It will require an 8-10 step process over 2 days. This is covered under the builders warranty as their subcontractor was at fault with the original floor. I'll try to provide some before and after photos. Work should commence the beginning of March.
Thanks for the advice and direction! Jim

[Ole Anderson]

I will be watching for your update, pics please!