backdrops

I am looking to use vinyl sheets (wall material, Menards) with one textured, one smooth surface. Cutting 4 x 8 sheet to about 3’ high for backdrop but mounting instructions call for 1/8 - 1/4" for expansion (even though its synthetic). How are others mounting sheets of whatever to get continuous backdrops (all layouts seem to have them) allowing for expansion and not exposing the wall behind?

One seam I can back-laminate a 1’ strip of material at the coner of the layout where I have a radius allowing for movement. Also wondering about adhering it directly to wall or hanging it from screws in sloted holes at cieling.

Thanks much, SM

Do the instructions recommend how to cover the seams when used on a wall? Maybe you could use the same thing. It would probably show , but you might be able to live with that.
Another thought - allowance for expansion may not needed when used as a backdrop. It’s probably recommended because of the possible expansion of whatever it’s mounted to, rather than the material itelf expanding.

No mention of method to cover seam on product instructions. May try packing tape or other on the back side and then latex caulk seam before painting… may do job and lay flat avoiding shadows.

Maybe there’s some info available at Menard’s? Printed, good luck asking anyone! [:D]
I’m visualizing a rubber or plastic strip of some kind, shaped like a “T” in cross-section, where the vertical part of the “T” slips between the two sheets and the horizontal part covers the seam. [?]
Bill K

PS: You might look into using linoleum (or whatever it’s called now days.) That way you might get around having seams altogether.

I suspect the sheets you are looking at are intended for outdoor usage with expansion rates like that. Vinyl flooring and linoleum don’t have that kind of an expansion problem. Vinyl siding does because of the great temperture differentials it sees so it is installed so it hangs from the nails and can move. The more unifrom the temperature in the area of your layout the less expansion will take place. My guess is if you use something like liquid nails at the seams with a 1"x4" and 2" of glue surface on each panel you won’t have an expansion problem at all. Might be worth making a frame of wood and mounting two panels. Then you could place it outside for awhile to see how much shrinkage or expansion does take place. Don’t know where you are but a couple of weeks at this time of year in Chicago will give you a temperature range far in excess of any indoor settings.

Bill K - the "T"s sound like a good solution to mask seam location. May be a little tricky once painted of un-painted areas start to peek out.

ndbprr - am fully aware of the temperature fluctutions, get your weather half a day later here in Milwaukee. Having a basement location with relatively constant temperature should limit expansion. Mostly a humidity issue - should have measured sheet in mid summer and again now to see if there was any change. Your point makes sense and am thinking butted panels won’t be a problem. Thanks all. Will post pics soon (?).

Well you should be able to measure the sheet width in your basement or wherever and the n just take it outside in the sun. We should be forty tonight and suppsoed to be in the seventies next week so it should approach eighty degrees in the sun for a remeasurement. Measure the longest side. Vinyl should not be affected by humidity at all. It isn’t hygroscopic (absorb water).