# Commercial vinyl over commercial vinyl



## Ze Paynter (Feb 20, 2015)

I need to explore this a little bit and get some feedback. 

The wallcovering came up short for a small job in a fast food restaurant. They ordered more but it's a different run and doesn't match well. So they decided they just wanted to go over top of the old with new wallcovering. 

They asked me about doing that and I immediately thought that might not be a good idea. But I have to say, many years ago I worked on a big job hanging commercial vinyl in a large building where they did just that. They primed over the old and just hung new over top. As far as I know it worked out OK but I never got to go back and check in a month or a year later to see how it went.

Commercial vinyl is pretty water proof and I'm pretty sure it took at least a month or MORE to really dry. One hanger said they once put paste on some vinyl, folded it in 2, then came back a month later, opened it up and it was still wet! So that doesn't sound good. And was there enough mildecide in the paste to keep it from getting moldy?

I did think of a way to do this though and wondered what you thought. What if I primed over it first. Then got one of those paper tiger things to perforate the surface and went over the whole area (it's not that large actually) to introduce little areas for moisture to work it's way out. Next give it a quick sanding to knock off any perforations that might be sticking up. Then hang the new vinyl. Maybe this would suffice. Any thoughts on this?


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## Brushman4 (Oct 18, 2014)

Go to any of the major hotels in the Chicago area and some of the rooms have up to four layers of 54" vinyl. Some jobs got a coat of wall prep before the next layer, but most didn't and were just hung with vinyl over vinyl paste. https://www.homedepot.com/p/ROMAN-PRO-555-5-gal-Extreme-Tack-Wallpaper-Adhesive-011905/203350732

I've worked on too many of these project to count, and hotel's do it to save money in the short term.
Eventually, all these layers will start to crack or loosen up, and that's when the hotels have to bite the bullet and sometimes have to re-rock and tape these, followed by new vinyl being hung!


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## Gwarel (May 8, 2012)

I've done it but it is against manufacturers recommendations and will void any warranties, so I make sure they know there is no guarantee whatsoever. I use R35 on the existing vinyl and make sure my paste is not heavy. It's going to cause bubbles so you have to go back over it and sweep out air, usually for a couple of days. One of the biggest problems is cutting through the existing VWC when cutting seams, which of course can cause the original to open up under your seam. I use a seam buster for this, I think I have a picture I can attach.


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## Woodco (Nov 19, 2016)

Gwarel said:


> I've done it but it is against manufacturers recommendations and will void any warranties, so I make sure they know there is no guarantee whatsoever. I use R35 on the existing vinyl and make sure my paste is not heavy. It's going to cause bubbles so you have to go back over it and sweep out air, usually for a couple of days. One of the biggest problems is cutting through the existing VWC when cutting seams, which of course can cause the original to open up under your seam. I use a seam buster for this, I think I have a picture I can attach.


I bought one of those things, and I couldnt get it to work on vinyl OR paper.


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## Brushman4 (Oct 18, 2014)

Gwarel said:


> I've done it but it is against manufacturers recommendations and will void any warranties, so I make sure they know there is no guarantee whatsoever. I use R35 on the existing vinyl and make sure my paste is not heavy. It's going to cause bubbles so you have to go back over it and sweep out air, usually for a couple of days. One of the biggest problems is cutting through the existing VWC when cutting seams, which of course can cause the original to open up under your seam. I use a seam buster for this, I think I have a picture I can attach.


I didn't say it was the best practice or that manufacturer warranties would be upheld, just that most major hotels would except this to save money every 4 or 5 years!


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## Brushman4 (Oct 18, 2014)

Woodco said:


> I bought one of those things, and I couldnt get it to work on vinyl OR paper.


Did you use the proper blades? You can usually only get 1 or 2 cuts off of each edge before having to flip the blade over.


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## chrisn (Jul 15, 2007)

You would be wise to check the fire codes. It is illegal most of the time


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## Gwarel (May 8, 2012)

Woodco said:


> I bought one of those things, and I couldnt get it to work on vinyl OR paper.


It takes a little practice. You have to start your seam for about 4" with your standard blade then insert the seam buster, then finish it manually at the floor. PITA but it works.



Brushman4 said:


> Did you use the proper blades? You can usually only get 1 or 2 cuts off of each edge before having to flip the blade over.


Right on, it's a rounded edged blade, four corners per blade.


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## Woodco (Nov 19, 2016)

Yeah, I got the right blades. I didnt start my cuts by hand first though. If I didnt throw it away, I'll try it again.


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## Gwarel (May 8, 2012)

Woodco said:


> Yeah, I got the right blades. I didnt start my cuts by hand first though. If I didnt throw it away, I'll try it again.


Just curious, and this is for whoever is reading, do you use a straight edge when cutting seams?


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## Woodco (Nov 19, 2016)

Yes. But, I also do a lot of what Jim Parodi calls "curved double cuts" especially in corners, but thats kind of a different subject.


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## Brushman4 (Oct 18, 2014)

Gwarel said:


> It takes a little practice. You have to start your seam for about 4" with your standard blade then insert the seam buster, then finish it manually at the floor. PITA but it works.
> 
> 
> 
> Right on, it's a rounded edged blade, four corners per blade.


Great point Gwarel, you must start the top of your cut with a razor blade /knife so you have room to get the seam buster in place! I assumed most would know this, which is why one should never assume anything.


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## Woodco (Nov 19, 2016)

Brushman4 said:


> Great point Gwarel, you must start the top of your cut with a razor blade /knife so you have room to get the seam buster in place! I assumed most would know this, which is why one should never assume anything.


I dont have anyone on hand to teach me these things. I've also read that they dont make the best cuts anyway, so I only tried to test in on a couple scraps. Knowing me, I probably threw it in the garbage. I use Boggess strips for my double cuts anyway.


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## Gwarel (May 8, 2012)

Woodco said:


> I dont have anyone on hand to teach me these things. I've also read that they dont make the best cuts anyway, so I only tried to test in on a couple scraps. Knowing me, I probably threw it in the garbage. I use Boggess strips for my double cuts anyway.


I think a lot has to do with the blade quality. I bought mine over 20 years ago and the guy who showed me how to use it also encouraged me to buy a box of German blades at that time. I still have some of those blades, each one individually wrapped in a paper sheath, and they work great. They reason I asked about the straight edge is that, like with any cut, the angle of the blade has everything to do with the outcome. Even though the tool holds the blade, keeping the tool square to the straight edge makes a better outcome.


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## Woodco (Nov 19, 2016)

Let me reiterate, that I only tried it on a couple test scraps, not on an actual wall, so its very possible I just had a bad angle.


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## Brushman4 (Oct 18, 2014)

Like anything else, it takes time and practice to master the seam buster.


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