Am repairing post-flooding of a 2 storey rowhouse condo (built 1977).
Cement subfloor on main floor (no basement).
ISSUE: old carpet torn up in LR/DR (large rectange~300sf). Sticky mastic remains on the cement - shoes stick when walking. I've read that concrete must be clean, dry and flat before installing engineered hardwood (initial plan of glue down cork planks abandoned due to cost). The flood remediation contractor, the condo insurance company and my installer (relative with years of experience doing this) all argue the mastic removal and/or using levelling compound isn't necessary. A suggestion was to apply a sealer to smooth it out.
Finally, the insurance company agreed to removal of the mastic with a sander/grinder but, in the meantime, my father has gone ahead and applied a sealer to the floor so now there is even more to be removed, if it does indeed need to be done.
Again, from what I've read, the mastic (and now the sealer) should come off, the concrete needs to be assessed for cracks and moisture and needs to be levelled. Am I wrong? Is what I've read really "overkill" as I have been lead to believe? Also, I'm now considering a Kahrs 2 strip floor (long and wide planks) and have read that the level floor is even more important in this case - deflection etc. I don't want a squishy, noisy, cracking or broken floor! I would appreciate advice ASAP. Thanks. Jackie

Are you gluing or floating the Kahr's?

I'm floating it.

I've already purchased the Roberts Harmony 3-in-1 (red sheet with white balls on it); don't know why I'm describing it...I'm sure you know what I'm talking about.

Awaiting more expert advice.

Thanks in advance.

Some background history to explain why I really want one aspect of this flood nightmare to go properly....

A broken sink hose caused the flood. Approx. 3/4 of main floor was affected.

Wet drywall, flooring (carpet in LR/DR) and vinyl (entrance, down hall to kitchen on L and utility (washer, dryer, freezer) on R at back (opposite kitchen). Wet vertical drip marks down most walls (it was very hot and humid when the flood occurred). Second floor has 3 bedrooms and bath.

I had purchased the condo 8 months prior. It had just been renovated - new kitchen/flooring and painting throughout. I renovated the bathroom.

During the flood remediation process, the asbestos tile under the vinyl was removed improperly. I wanted it checked for asbestos but they assured me that it wouldn't be in 9x9 tiles. They were pulverizing it with a machine and sweeping it into big dusty piles, no plastic sheeting to prevent dust from going everywhere, all of my contents were still in the living/dining rooms.

Then there was still moisture in some areas on days 3, 4 and 5 post-flood. They removed my contents into external storage.

An independent asbestos remediator discovered mould..... weeks have turned into months. The asbestos and mould has been removed (currently at my expense). The flood remediation company, the condo corp. insurance co. and my insurance co. all want this to just go away and are arguing over who should have to pay what and are offering amounts that don't come close to covering the cost so far.

My initial flooring installer had 2 windows of time to install my floor this summer but I missed both of them which resulted in hiring my cousin. He installed my tile ~ 3 weeks ago and was ready to install my hardwood but I was still concerned about the mastic issue I described earlier so he carried on with another job.

The company that said they could remove the mastic was now too busy (for several weeks). My dad went ahead and painted that sealer over the sticky, old, uneven mastic (without my knowledge) to "level it out" as suggested by one of the folks who are only interested in the cheapest fix, not the proper fix.

I ordered engineered hardwood flooring from HD which arrived almost a week late and was the wrong flooring (3/4 inch solid arrived rather than the engineered I had ordered).

That icing on the cake was yesterday. I shopped all over town yesterday, looking at what was in stock and that's when I came across the Kahrs, 2-strip, no-glue Navarro flooring (both wide and long). The color is not exactly what I wanted but at this point, it will do. My cousin is available to install it Saturday (today being Wednesday). It needs to acclimate 2 days minimally (3-4 ideally) and I'm getting pressured to forget about the removal of the mastic/sealer, the floor levelling etc.

I want to know what SHOULD BE AND NEEDS TO BE DONE for this flooring install to be done properly. Also with my cousin doing this, it's not as if I can easily tell him to rip it out and redo it if he botches it.

Any expert opinions welcome.

I feel like I need a beer and I don't even like beer!

Jackie

The way I see it, if the floor is not sticky anymore just lay the underlayment over it. That's one advantage of using floating floors...the subfloor does not have to be pristine. But don't neglect flatness.

I don't understand the use of the sealer to smooth it out?

Thank you BW and Ken for your responses to my post. Ken, your comments have lead to more questions....

Regarding the SEALER to "smooth it out"...

- that was the recommendation of one of the insurance adjustors, I believe, as a quick fix (I believe the implication was "just paint or roll another layer on there"= cheap fix rather than grind/sand off the mastic and level the floor properly = more expensive fix, at least that was what I took away from that suggestion).

In any case, I was wrong about the product being a floor sealer. Upon further discussion with my father today, he clarified that what he actually did was to use a paint roller and roll primer over the uneven mastic that was/is stuck to the cement floor. I don't believe that it is flat though, just by looking at it but I will check tomorrow using a board.

My questions now are, and I'll number them so anyone who has advice can address them as such:

1. So, Ken (or any other folks out there) you are suggesting that if the floor is flat, which is yet to be determined (ie. according to Kahr's installation guidelines re: flatness of floor) that the removal of the mastic and primer may not be necessary?

2. I did contact the company with the grinder today and they are going to get back to me, hopefully tomorrow, re: if/when they can remove those layers for me. If they can do it soon, I'm assuming that it would still be better to have that stuff off. Yes/no?? Any opinions out there regarding my assumption??

3. And, if it is NOT FLAT, which I suspect is the case, should I then wait until it can be removed before proceeding with the install?? Including possibly using self-levelling compound prior to install if needed??

4. And, if it is not removed, how can I assess the quality of the cement subfloor (ie. cracks)?

5. Can I assess the moisture of the cement floor with the 2 layers (mastic and primer) on it?

I purchased the Kahr's floating 2-strip engineered floor today (Wednesday) and got it into my condo ~ 5:30 pm. My cousin is available to install it Saturday am.

6. Under ideal conditions (ie. floor is assessed as FLAT enough tomorrow without requiring removal of mastic and primer), isn't Saturday morning still a bit early for proper acclimatization (it will only be 2 1/2 days at that point)?

Again, thanks in advance for further advice.

Jackie

Read the instruction for conditions that must be met before installation begins. Especially the part about interior ambient air conditions.

1- Yes
2- Refer to #1
3- Yes
4- Cracks? It's a floating floor. No concern
5- I really don't know the answer to that one. Never been there.
6- Some manufacturers don't even specify acclimation. It's your floor, play it the way you want, preferably the safe way.

The original 9x9 tiles probably had asbestos in them. Asbestos was still being used in 1977 in floor tiles. The adhesive was old asphalt based "cut back" or "cold bond", which again, probably contained asbestos. These are not problems unless disturbed. A floating wood floor is ideal in this situation. But the substrate must be flat to Kahr's specs. So far, you have gotten bad and faulty advice from everyone except the posters on this site. Kahr's is an excellent manufacturer and has tons of info on their site. Once it is determined the substrate is flat enough, install one layer of 8 mil polyethylene plastic sheeting over the entire substrate. Overlap any seams by one foot and tape completely using duct tape. Lap the sheeting up the walls by 4" and tape or staple temporarily to the walls (to keep it out of the way of the install) then you will install the recommended foam underlayment. There are various ones available. Many like the "Floor Muffler". After the underlayment, install the Kahr's flooring exactly as the directions call for. Do not deviate from the directions. You will need a "pull bar" and a good tapping block (even though it is a click system now ), hammer, saws, tape measure, etc. Don't not neglect to provide proper expansion around the perimeter. You should have no problems if you follow the directions. Kahr's is an easy install.

Hi again,

I'm back with what I hope will be my final question.

My floor IS NOT FLAT - out by up to a centimeter in places, which is way more than the Kahr's specs. which call for a max of 1/8th of an inch.

I was prepared to follow the advice I've received on this forum which would be to grind the primer and masic off and then use self-levelling compound prior to having the engineered hardwood installed....however...

1. When I requested written confirmation (have only received verbal to date) that the insurance co. will cover the cost of the grinding, they did not call me back (it's been 2 days now)....

2. My father has received another suggestion for which I am requesting more expert advice if you would be so kind....the suggestion is:

TO BUY AN EXTRA ROLL OF 3-IN-1 AND TO CUT IT UP INTO PIECES TO FILL THE LOW SPOTS.

My father's concern is getting this whole mess settled before he heads back to Florida in 3 weeks. He is right that it would certainly speed things up. He doesn't want to leave me here to fight with the insurance co. and the initial contractor re: who is going to pay for what. I admit that I am also concerned about having to fight that battle by myself. My cousin is literally available at this very moment to start if this is a reasonable idea.

Thanks again,

Jackie

Will not work. The subfloor condition will become too spongey. Finished floor may become bouncy and creak at weak joints when stepped on. I'm in favor of getting it right regardless of your schedule. We sure don't want to see you come back and hangin' out in the "Yike I Have Problems" area.

Ken,

I read your post early this am.

I received a call and the company can grind the floors @ 8:30 tomorrow morning which is good news.

Thank you for your advice.

Jeze-

I hope you took note of Gary's concern that the mastic most likely contained asbestos as well. If this is to be ground off, containment measures must be adequate for such a removal. Chemical removal has been an alternative that works without the problems of asbestos dust.

Just make sure this company is aware of the asbestos issue and is dealing with it professionally.