Paint overspray on gypcrete [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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Tom H
01-11-2004, 02:46 PM
We are building a 3,300 sq ft house on spancrete which is the second floor of our project. The drywallers got paint spray all over the floors. We are going to be laying about 2,500 sq. ft. of marble tile on the gyprete. The big question here is "do we have to remove the paint overspray" in order to lay the tile??

And if so does anyone know the best and easiest way to remove it. This could be a huge project that we had not planned on so don't know if it is worth the trouble.

I wish we had found this site earlier!!

Tom H

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Sonnie Layne
01-11-2004, 03:06 PM
It's been said many times before on this site that yes, you must remove the paint. I sometimes wonder why, if the paint is thoroughly bonded, but I haven't been setting tile for 30 years either. I am a painter, however ;) I don't know spancrete, but I'm assuming it's some kind of cementitious product. A disk type floor sander with coarse scothbrite or sandpaper would be a place I'd start at removal.

Tom H
01-11-2004, 03:09 PM
I was afraid you were going to say that.

Thanks for your help!!

01-11-2004, 03:45 PM
Tom it will come right off just be sure to wear a HEPA mask and have a shop vac running constantly. Lots n Lots of dust.

Hope your planning to seal that stuff whether you sand or not then use Ditra wherever you tile.

Leaving the paint would be extremely risky if not downright foolish.

Me, I would make the painters clean it up.

Sonnie, Spancrete is a flooring system of basically concrete planks the gypcrete or a SLC is poured over them to level the floor (planks)

Sonnie Layne
01-11-2004, 03:59 PM
Thx Jim, I'm seen what you're talking about, just never worked with it or knew what it was called.

Tom, if you use the scotchbrite pads on the disc sander, you can moisten the surface just a bit to help control the dust. Jim's right, it's gonna be a nasal nightmare.

Tom H
01-11-2004, 04:07 PM
I really do not know much about the Ditra so will have to research it to see if it is applicable. We had gypcrete and radiant heat in our last home (for 14 years) and just bonded it with thinset and had no problems.

I do think we should seal our floors now with something as any water now just runs through the gypcrete, throught the 3" concrete topping and through the 10" of spancrete..

Once again I sure wish I had found this site sooner.

01-11-2004, 04:09 PM
Hi Tom, great name!
Before you worry too much about the paint you should consider whether you need that flexible membrane before the tile. Gypcrete very often cracks. Lots. And it's likely to come right through your marble. I would also recommend you look at something likt Ditra or Nobleseal as an underlayment. If you do that, then the paint may not be such a big thing. Not sure about noble, but I know the Ditra has a low sheer strength requirement under it, around 50 lbs. Most paint is stuck better than that, so that might drastically change how perfect you actually have to be on getting that paint off.

Tom H
01-11-2004, 04:13 PM
Anyone care to share the approximate cost on the Ditra? It might be worth it and thanks for the suggestion I will contact the painters and see if they will clean it up..Thanfully I have not paid them yet!!

Tom H

Sonnie Layne
01-11-2004, 04:20 PM
Ouch!!!!! Dang it, I told you I was a painter, did I not? :) I know... bidness is bidness. is one place to get it and lots of answers. David Taylor's a member of our forum.

Tom H
01-11-2004, 04:22 PM
Somehow I think that you would have been smart enough to cover the floor before spraying the paint.

Thanks Again

Tom H

01-11-2004, 06:15 PM
First, kill the painters. :mad:

I give the painter a copy of the floor plan and elevations for his bid. If it says anything other than carpet as finished floor on the plan and he paints the floor, he cleans it.

That said, I think the gypcrete people want you should seal their stuff anyway, so having some paint on the floor may not be as bad as we think, especially since I believe you really need to install a membrane to lay stone over that stuff.

But kill the painters anyway. :D

Tom H
01-11-2004, 06:55 PM
Well that is certainly an interesting concept!

The painters worked for the drywall company and none of them spoke english so I would probably have to take it out on the salesman for the drywall company..

You know, we got literally no information on the care of gypcrete except that we should not get it wet.. We will call them tomorrow to see if they have any advice. It cost us $6,800 for 3,300 sq ft of gypcrete and no directions included.. and to make matters worse it took them about 3 hours to pour it and 3 to 4 weeks for it to dry.

Quite a field to be in I would say.

I will let you all know what they say tomorrow.

Thanks Again

01-11-2004, 07:18 PM
How deep is that pour? That's $2.06/sf

3-4 weeks to dry? :rolleyes:

Tom H
01-11-2004, 07:26 PM
That's right about $2.00 per sq. We have about 3 companies locally that do it and they were all close in their price.

The radiant heat wasn't and still isn't working so the temporary furnace couldn't heat the place up enough to dry it faster.

Maybe that is why the painters were in such a hurry that they didn't cover the floors. Poor things were cold..

As Gilda used to say "If it ain't one thing it's another"

01-11-2004, 07:40 PM
Hi Tom,

Where is Waukesha are you building?
Who is you HVAC contractor and who did the gypcrete pour?

I doing a radiant heat install in Muskego although it's only around 2100 sq ft.

My installer will be leaving with me a quantity (unknown to me) of the sealer, so I can seal the gypcrete before I install Ditra on the floor.


01-11-2004, 07:45 PM
The radiant heat wasn't and still isn't working so the temporary furnace couldn't heat the place up enough to dry it faster

What was the temp in there when they poured it?

Better read these, I don't know if you have Maxxon Gypcrete or Hackers. Gypcrete has become a generic term for gypsum underlayments although it is a Maxxon brand.

Maxxon Thermal Floor


Tom H
01-11-2004, 07:46 PM
We are downtown Waukesha on W. Main Street. We bought an old 50's car dealership, tore off the roof and put down the spancrete for our loft

Rozga is our HVAC contractor and Accoustical Floors out of Hartland did the pour.

Who is doing yours? Are you pleased with the product so far?

Tom H
01-11-2004, 07:52 PM
It was about 58 degrees but probably did not have as much circulation as it should have. The large areas such as the living room and kitchen dried within a week but the bedrooms which were in the back of the house did not.

I probably did not mention that the heat was down below and the we had a huge fan blowing the heat up the stairs.

I did get that flyer from that site that you sent but I still did not expect it to take so long to dry

01-12-2004, 06:28 AM

Accoustical Floors is doing my pour with Maxxons Therma-Floor god willing next week. We just has the well drilled and need about 1000 gallons of water to do the pour. Problem is with the all the water that was pumped out during the well drilling process and the warm temps the well truck might get stuck in the mud. So they are waiting for the ground to freeze.

Once the well truck is out they can put the pump in as well as the lateral.

My heating contractor is Lake Country Heating and Cooling.

What kind of boiler are you putting in? We are having a Monitor MZ boiler installed.

Are you have with the work Accoustical Floors did? Did you have fiberglass screen placed in your gypcrete where you are going to be putting tile?

The temporary furnace in our house has been able to maintain about 60 degrees. I will be putting in a couple of dehumidifies to help get the water out as well.

If everything goes as planned we will be turning on the radiant about 3 hours after the gypcrete has hardened. Then use the heat from the radiant to help dry it out.

We will see. I need to call Maxxon and get exact details.


Tom H
01-12-2004, 02:30 PM
Hello Pete

We are having a Buderus boiler placed and no we did not go with the fiberglass screen.

I see that you are using Accoustical Floors for the gypcrete. We used them last time (14 years ago) and again last month. They are a good company, I just wished I had had better information about the drying time on the gypcrete.

It also would have helped if the HVAC guy had the heat in. It is still not in and now he is holding up the drywall and electrical in the lower level.

We are placing tile on about 2,500 sq ft so it is no small job.

Since you are so close you are welcome to come over and see our gypcrete if you are so inclined.

01-12-2004, 07:28 PM

Send me your address and I will swing by.
It's nice to find another tile/radiant type not to far away.


Tom H
01-12-2004, 08:11 PM
431 W. Main St..

01-12-2004, 11:51 PM
Did you guys ever price out a portland SLC instead of using gypcrete?

01-19-2004, 06:37 AM
So Tom how is it going?

My HVAC contractor removed the temporary furnace from the basement and connected the Monitor MZ boiler. All loops are up and running with no leaks.

I am able to pretty much able to heat the house by heating the basement at full tilt. Basement temp is 78 degrees which is keeping the upstairs about 65 degrees. The zones upstairs kick in periodically.

Spent most of the weekend spraying foam insulation around all of the windows and doors and general vacuuming the house for the gypcrete pour tomorrow morning 8:30AM.

In the process of acquiring buying/borrowing 3 dehumidifiers so on the pour is complete I an start getting the water out.

Has your HVAC guy got your boiler connected yet?

I spoke with Maxxon on Friday and they figured it will take about 2 weeks of heating the slab and dehumidifiers to get most of the moisture out. I will still have to check it via a piece of plastic taped to the floor for 48 hours though.

Good luck, hop to hear from you.


Tom H
01-19-2004, 06:49 AM
Hi Peter,

We are up and running as of last week.. The Buderus is humming along just fine and we maintained about 68 degrees all weekend.

The temporary furnace is still doing its thing in the lower level (7,200 sq. ft) but the floors are toasty upstairs.

Heh, I forgot to mention that as the gypcrete dries it gives off a fuzzy covering that needs to be swept up regulary. We called Accoustical floors and they said not to worry that it was normal. We thought we had mold at first.

Did I tell you that the morning we were set to pour a water main broke on our street and the main supply of water was shut off to the building. The City guys were great though and let Accoustical hook up to a different main across the street. I thought I was going to have a stroke when I got the call at 6:00 AM.

Good Luck tomorrow
Keep us posted

01-19-2004, 07:09 AM
Tom, I am going to step in here ang give you a bit of advice as to the use of Ditra.
I have done many commercial buildings with spancrete used and gypcrete pours over this.I have also done repairs in several which were not done correctly.Anytime i have seen Gypcrete used over spancrete without the use of a membrane,I have seen straightline cracking in one way shape form or another.
Giants Ridge Golf corse and Motel complex(a several Million Dollar commercial structure) has had several instances where straightline cracks were repaired(fortunatly they have a 15 year maintenance contract with Lakehead constructors).
Americinns are built with Spancrete/Gypcrete on all above grade levels.Older applications saw many problems.Some of the Newer buildings in the Blandin(now UPM) Papermill have had similar problems .
I cannot stress enough the need for a Membrane considering the amount of S/f you will be dealing with.
Ditra Works and works well for just exactly this type situation.Do yourself a favor and eliminate the potential problem from the git go.Use Ditra(or at the very least,upgrade your homeowners insurance to cover all the future repairs!!)

Tom H
01-19-2004, 07:37 AM
Good Morning Todd,

I don't know if I mentioned it but we did pour a 3" topping over the spancrete before the gypcrete as there was quite a tamber to the spancrete and we had to even it out. We also did not want the house sitting right on the spancrete.

Are you suggesting the Ditra now before we tile? My concern of course is cost. The spancrete ran around $28,000 and the 3" topping was about $9,000.

I have not checked yet the cost of the Ditra but did check out their website. It sure looks impressive.

Thanks by the way for your comments I appreciate the input.

01-19-2004, 07:41 AM

Yeah the water thing threw me for a loop. AFW never mentioned they needed 1000 gallons of water. So I couldn't proceed until our well got put in. So now that it is finally in we can procced.

It would be nice if the contractors would spell these things out in their bid. Oh well.


I have always planned on putting Ditra down where ever I was going to be tiling. You and John as well as countless others have learned me real good.



01-19-2004, 07:59 AM
Tom, when you poured your 3" topping did you use a slip sheet between the spancrete and the topping??
Also, did you leave expansion joints in the topping??

Ditra will run you around 135-150 s/f aprox.I believe David Taylor probobly has about the best price available online that I have seen.there is a link in our store to his site
He will certainly be happy to give you a quote.

Peter, glad to hear we have been of help to you,it never hurts to hear we have been able to accomplish somewhat what we have set out to do in this forum.Thanks :)

Tom H
01-19-2004, 08:09 AM

Nope, we did neither..No one told us it was necessary. We will definietley look into the Ditra. We are about a month away from tiling so your advice was very timely.

Thanks again

01-19-2004, 02:26 PM

Just a double check. I am having 2100 sq ft of gypcrete poured tomorrow. The company the is doing the install has been doing this for 18+ years. Should there be expansion joints in the gypcrete?
The gypcrete is is being poured over an OSB subfloor which the installer will prep with a secret solution prior to pouring the gypcrete.


Tom H
01-19-2004, 05:12 PM

I think you have radiant heat tubes in that gypcrete don't you.
I don't think I would want anybody cutting expansion joints in it!!


01-19-2004, 05:15 PM
Oh! Good point. Never thought of that.