Concrete step repair?

[john619]

Looking for suggestions on the proper way to repair these deteriorated areas on an existing set of stairs prior to re-tiling them with a lasting repair in mind. Southern California coastal location.

Once all of the loose and unstable concrete is removed, is there a mortar that is designed for this kind of repair, possibly needing a bonding agent or something?

There are some deteriorated sections of metal angle that will be replaced.

Thank's for looking.

[Davy]

John, the light colored mortar just under the tiles is thinset. Chip or grind that away down to the gray mud. The voids in the mud can be patched in using fresh wall mud with a skim coat of high quality thinset as a bonder. The wall mud will be harder and stronger than deck mud. Once the mud is patched up, then the stone can be installed back trying to get 100% coverage with the thinset.

[john619]

Davy, Thanks for the response.
Yes, they will be removing all of the loose material and steel angle that we will no longer need. The existing stairs have a shadow reveal detail in the riser that is no longer compliant with accessibility codes. We are going back with a traditional angled solid tile riser. The tile subcontractor has submitted Platinum 254 as the bonding agent. I see where that can be used in that manner, but I believe they are also intending on using the 254 as the tile bed mortar. Is that a good choice for this purpose? The manufacturer's spec. sheet makes it sound amazing, but I am curious why they never specify a maximum thickness that 254 can be applied? I guess it is not a "thinset" and can be used in thicker depths?

[cx]

Originally Posted by John

The manufacturer's spec. sheet makes it sound amazing

At more than $50 a bag, John, I think it certainly should be.

Originally Posted by John

I guess it is not a "thinset" and can be used in thicker depths?

Thinset or thin-set is a method, not a material. While that 254 mortar says it meets ANSI A118.15 as a "super mortar," I see no T in the designation indicating that it has non-sag properties, which is usually an indication that the manufacturer is going to indicate it for use in thicknesses greater than 1/4-inch. But even those mortars that are indicated for use in thicknesses up to 3/4-inch are still thinset mortars.

In any case, from their TDS, Laticrete intends it to be used as a thinset mortar and nothing else. If you want to build up those repair areas, you'll want to do it with something other than your thinset mortar.

My opinion; worth price charged.

[john619]

Thanks CX for the response. The Contractor has responded that the 254 is intended to be used as a bonding agent. They intend to use Quikrete Deck Mud for the repairs and forming then go with the 254 again to set the tiles.

Does that sound correct?

[cx]

Not really. I've never used the Quikrete Deck Mud, but if it's mixed as deck mud it's not really the right product for that sort of repair. It's possible if that product is mixed with more water than one would use for deck mud that it will function as a patching material. I guess you'll find out.

If nothing else, I'd surely want them to use some thinset mortar as a bonding agent to bond that Deck Mud product to your old concrete.

My opinion; worth price charged.