Topic: using densifiers to try to fix concrete laitance (soft chalky surface)

[jonda500]

Just wondering if anyone has tried this? It is the only concrete sealer product that doesn't require removing (planing/grinding/acid/etc...) the soft chalky layer first before applying, and it can be applied with paint rollers. (By me!) A short back story..
   My double garage cement came from a truck that got rejected from a building site so they used it for my garage . Then they left one guy by himself with the helicopter machine, a bucket of water and a hand trowel trying to smooth it out for over 3 hours!! At this stage I have moved past being depressed or angry at the builder/cement guys. I don't know if it's worth $300 for lithium densifier, but it is the only option I can see myself doing aside from doing nothing and learning to live with it. If money wasn't a problem I would get it ground down to a hard surface, then get a surface leveler layer poured and then get it poly-sealed.
John

[Don R]

 I have not seen that used but it might be worth a try. It's not cheap at all but terrazzo grinders do an amazing job. A soft top layer would probably negate that. I worked in an old gym where they used a scarifier machine to remove the top layer from the locker rooms and then re-poured it. My goodness what a noise that thing made, it had a rotating drum with carbide tipped teeth.
 I wonder if those plastic interlocking garage floor grids would stay put on it?
  My garage was owner built and it got a couple floor cracks that blew out over winter. It seems I have rusty re-bar close to the surface. I'm planning to cut them out with an abrasive wheel before using a latex patch mix on it. The truck parked there since 2003 rarely sees salt but apparently there was enough in the past to seep in.
 The new I74 bridge over the Mississippi river was recently built with 100% stainless steel wire and re-bar to keep that from happening. Hopefully the beams were also rust proofed with something besides paint.

[Kelly E]

At my last house I had the shop built and the cement contractor showed up when I wasn't home and poured the 24'x36' floor left side and then the right side. It had a 16' wide roll up door on the 24' gable end and the seam ran back to front right out of the door in the middle. It was supposed to be poured in three 12'x24' sections starting at the back.

Ten years later the floor had cracked right down the middle and it ended up heaving up in the middle at the front so much I could barely lock the roll up door. I felt bad for the new owners but they said they didn't care and would fix it because it was a very private 5 acres and they wanted the hell out of Seattle. My current 30'x48' shop has cracks but the slab is at least 8" thick so there's no issues.

I would try the $300 fix and start saving up to have it ground down to solid and a new layer poured in case it doesn't work.

[Tracksnblades1]

An epoxy floor looks nice…

[jonda500]

  Thanks guys. I've purchased 20 liters which should be about twice as much as I need depending how much it soaks in - the product needs to be applied and re-applied until the entire surface is wet, but with no pools left.
  The temperature during the 24 hour curing period has to remain between 10 and 30 degrees celsius so I will have to wait a couple of months for things to warm up. Meanwhile I still have to de-grease and and sand the surface. My datsun kingcab and my #2 CB 500 have left dozens of oil drips for me to clean up!
  Most of the contents of the garage are currently all packed into my lounge room including all my tools, workshop equipment, garage-analia, honda parts collection and my honda motorcycles!
  I am maybe a third of the way into completely re-wiring, insulating and lining the garage with marine plywood to make a pleasant comfortable work environment for myself, my stuff and my bikes.
  I have a lot to do before getting back to wrenching/fixing the bikes. I plan to remove the engine (broken 3rd gear) from the bike in the garage to make it lite enough to put it in the lounge room by my self (the other two complete bikes were exceedingly hard to get inside even with two friends helping).
  The floor should never flood ever again and I have installed four windows in the south side wall (the not sunny side!) and turned the east side window opening into a lovely hand made barn style door with colorbond sheet on the outside (shed came with a spare sheet!). Good times ahead.
John 

[BenelliSEI]

Sounds like you have it under control! Good luck, I hope that product works for you.

[jonda500]

Thanks John, the lithium densifier literature claims it will chemically harden the cement to be 40% harder and will also leave it suitable for cement polishing.
   This product is not available in my state so I had to pay $136 shipping which stung - but this was the cheapest in total cost of the 5 options I had to buy this stuff in Australia,
John

[BenelliSEI]

When I finally built the shop I have now, it took a whole year to get it just right. Keep pushing, it’s worth the trouble!

[jonda500]

A year sounds quite reasonable to me! I paid a deposit on the new concrete slab in 2019!! So everything that lives in my double garage has been crammed in my lounge room for over four years now - a frustrating state of affairs!
Thanks for your encouragement, it means a lot as I have to keep pushing myself to get this done. It will def be worth it .
John

[jonda500]

Finally got the shed completely empty again and applied the densifier with the 24 hours curing temp range falling exactly between the prescribed 10 and 20 degrees Celcius.
Doesn't seem 40% harder yet but feels smoother and looks less porous.
Now back to finishing the wall insulation!
Then comes wiring, finishing the plywood cladding, fitting power points and switches and then I'll start the ceiling - edge beams, battons, insulation, wiring, plywood, light fittings and finally putty all the gaps.
John

[Stev-o]

The concrete looks great, hope that works for you.

[calj737]

I’m a huge fan of the mineral wool insulations. Fire resistant, bug resistant, no itch, and better performing if moisture becomes a problem. Super easy to install and barely
More expensive than fiberglass.

[jonda500]

Thanks for the replies, I really appreciate the encouragement!
My top picks for insulation were lambswool, aluminium honeycomb or hemp. However, "earthwool" (mainly glass fibre) insulation was cheap and readily available at the local hardware store, so I caved and went with that. Bloody ITCHY all right - I got a nasty itchy rash all down my front for two weeks after installing insulation with my shirt off one hot day, lesson learned!
John

[Kelly E]

Fiberglass insulation is definitely a coveralls, gloves and mask operation. Back when I did custom remodeling we always farmed out insulation installation if the job was big enough along with drywall and roofing. It sure was nice that the boss man hated those jobs too. I would rather dig foundation trenches in the rain than do those three jobs. 

[Don R]

  I got a pickup truckload and a half of 6" rock wool from a construction job. It was spec'd, bought and the customer declined it in school classroom ceilings as a sound deadener.
  The Contractor said he wasn't spending the labor to return it and if I wanted it, to get it off the site. It insulated my son in law's cabin. You can practically heat that thing with a couple light bulbs. Not too bad to install either.

[BenelliSEI]

I had the three exterior walls of my shop spray foamed by a local contractor. It certainly works well and literally ties everything together and no vapour barrier required. One disadvantage is all my wiring and conduit needed to be 100% completed as it all gets buried.