How to glue 6-mil polyethylene sheeting to concrete

[Ray K]

The polyethylene sheeting I used under a Pergo floor was packaged in a roll, but folded in thirds so the roll wouldn't be 12'feet long but a more manageable 4' long. When I unfolded the sheeting, it didn't lay flat against the concrete where the folds had been. I thought the weight of the Pergo would flatten the folds with time. After two years, it still hasn't, with the result that there is noticeable springiness at some of the folds, and the edges of some of the flooring is noticeably raised.

Now I have to pick up a portion of the flooring and figure how to glue the poly to the on-grade concrete slab.

(Pergo says that seams between adjacent poly sheeting merely have to be overlapped several inches, not taped or glued. So my only concern is flattening the folds with glue.)

From googling around, I found suggestions for applying asphalt mastic with a fine-toothed trowel, waiting two hours, then pressing the poly into the mastic.

One person had success with 3M super 77 spray adhesive. Contact cement instructions don't mention either concrete or poly as acceptable surfaces.

Any other suggestions?

Thanks,

Ray

[Ed Pawlowski]

Nothing is going to work well. Glue does not stick to poly. You may get it to lay down with the heat of a hair dryer.

[ransley]

I thought pergo sheeting came in a roll, a hair dryer as EP said should work or electric paint stripper gun, just dont melt it.

[HeyBub]

6-mil poly can actuall push up an interlocked wood floor? One great sage said it best:

"I've been to one world fair, a picnic, and a rodeo, and that's the stupidest thing I ever heard come over a set of earphones."

I'd suspect a dip in the concrete. Are you sure the base floor is (gulp) level?

[DerbyDad03]

I've never done a Pergo floor, so this might seems like a stupid question:

How does a sheet of plastic that measures 6 millimeters in thickness keep a wooden floor raised off the subfloor?

Are you sure the subfloor itself isn't the issue?

[bob haller]

must be a sub floor issue, whats the sub floor made of?

sounds like concrete the plastic sheet is generally a vapor barrier.

might still be moisture issues if its concrete

[HeyBub]

Ah, good catch! The untaped (!) poly sheeting could let sufficient moisture through to ever-so-slightly warp the boards.

[EXT]

6-mil is not 6 millimeters, the short form is 6mm. 6-mil is 6 thousands of an inch, about two sheets of 20 pound (now that is another complicated scale) paper thick.

[DerbyDad03]

Other than the unit of measure error, I'm thinking it's still a valid question.

re: about two sheets of 20 pound paper thick

Actually, it's about 1.5 sheets...

20 lb. Bond thickness =3D 50 lb. Regular Offset thickness =3D 70 lb. Smooth Offset thickness =3D 80 lb. Gloss Coated Book thickness =3D 20 lb. CB Carbonless thickness=3D 0.004"

What's so complicated about that scale?

[Tegger]

DerbyDad03 wrote in news: [e-mail]:

It's pretty silly, yes. And "basis weight" is so steeped in time that no one can change it now.

Each type of paper's descriptor weight is based on a particular "basis" sheet size, that sheet size varying with the type of paper: 500 sheets of that basis size would weigh that many pounds. That's what's called the "basis weight".

I have a book at work that gives this in detail, including the basis sheet size for each paper type (we use a lot of 100# offset in our business).

And since you can compress paper fibers quite a lot or just a little, the overall thickness will be very close between the different weights. You need to get up into boxboard before thickness (8pt, 10pt, 24pt, etc) becomes the descriptor rather than basis weight.

To make things even more confusing, Europe and China use gsm (grams per square meter) as the descriptor, so it can be hard to find exact equivalents between theirs and ours unless you have a physical sample of the gsm board.

[Ray K]

This is embarrassingly stupid. Here's a look at what the problem really turned out to be.

That black thing, 1/4" thick at one end, is one of the spacers that's supposed to go at the base of the walls, to guide you so you leave enough expansion space around the perimeter. It's in the position I found it when I lifted the plank. I can't believe I missed seeing it when I originally laid the plank.

If you look closely at the top right corner, you'll see a diagonal fold of the type I originally thought caused the problem.

Thanks to all for your comments.

Dummy Ray

[Ed Pawlowski]

That makes more sense than the fold in the poly.

[hrhofmann]

And a lesson to be learned by all of us.

[aemeijers]

Chuckle. True story- 71 ford full size wagon, had a lump under the carpet on the front passenger footwell. Lived with it for over a year like that, finally one day I couldn't take it anymore. Removed enough trim to roll the carpet back, and damned if there wasn't a brand new ignition key assembly, with key, sitting there under the carpet. Some sort of production line oopsie, I guess. Wonder what they did with the next car down the line when they didn't have an ignition cylinder to match the doors?

Moral of the story- you ain't the only one to look at something and not see it, and lay floor covering over it.

-- aem sends...

[HeyBub]

Thanks for reporting the cause of the problem. Many of us can quit scratching what hair we have left.

[bob haller]

had noise in trunk, going around bends.

finally traced to wrench in gas tank,

1968 mailbu

[clare]

1972 Ambassador - noise in rear parcel shelf area - rolling on turns - rattle on bumps. A few trim screwa in a "box section" ov the bodywork

- solved with a Shutz gun of accoustic undercoating (rubberized tar) - shot a layer into the chanel and the noise went away on the next left hand turn.

Same problem and solution on a 76 Dodge? - ball bearings inside the frame section under the floor. Squirt. Brake. Quiet.

[Kate]

Don't feel bad. The same thing happened to me, and there were three other people helping me.

I just found this thread. Sorry I did not see it earlier.

Kate

[The Daring Dufas]

My late brother in law worked for a VW dealer back when they were selling the air cooled Beatles. He once told me that when they prepped the cars, they would often find German beer bottles inside door panels.

TDD

[pfoxharp]

found this thread while googling. i realize your problem turned out to be something else, but according to the 3M website, "3M? Blue 72 Spray Adhes ive" is exactly the right tool for the job. it specifically lists polyethy lene sheeting and construction vapor barriers.

(another site says double-sided pressure sensitive foam tape will work, tho ugh that would't have worked in your case.)