Question: We would like to know if it possible (would you recommend) hanging a second layer of Dreamscape over the top of existing Dreamscape wall, as my customer would now like to change the image. Customer does not want to take the time/labor to remove the material. Is there a concern for a moisture barrier between the two products? Any guidance you can offer is appreciated. Wallpaper over wallpaper.
This is an interesting scenario. We typically do not recommend doing this for several reasons:
1. Dreamscape products have not been tested or designed specifically for the purpose of being applied over existing vinyl
2. Dreamscape has no data to understand how the double layer effects flame and smoke requirements ( if that is even a concern for your project).
3. Dreamscape vinyl product is pretty heavy to start, adding a 2nd layer would make the combined weight 40oz, not including adhesive, to support on wall. Is the quality of the initial install sound enough to maintain another layer on top without peeling? Remember both layers are completely dependent on the bond of the original layer to the wall. So the failure could come from a weak or poor bond of the adhesive holding the first layer to the wall.
4. I'll add your concern about the moisture barrier here- although I feel this is a smaller concern. In reality all vinyl wallcoverings that have not been specially perforated to allow transfer of moisture, will already be a solid barrier so adding a second layer doesn't change anything. You already have no transfer of moisture even with a single layer of wallcovering.
Despite not recommending it - the fact is that people do, and have done exactly what you are asking. We would never suggest it - but it is nothing new really and many pro installers have been asked to do the same. The most common reason for doing this is because the client does not want to incur the added expense of having the old wallcovering removed and the wall surface repaired.
So if you are forced to do this you should minimize your risk by following these pointers:
A. Make sure your client understands the risks ( review the 4 points above).
B. Try to verify that the first wallcovering layer is adequately adhered to the wall. If seams between panels are popping, or if corners are dog eared, or if the existing wallcovering is not in good condition, you would be better off removing the old wallcovering first then preparing the wall by following the standard Dreamscape installation instructions.
C. Make sure to use a good VOV ( "vinyl over vinyl") adhesive to bond the 2nd layer of wallcovering over the first. Standard adhesives that bond to wall will NOT bond well to the vinyl surface of the first layer of wallcovering. For example: Roman PRO 555 or comparable
D. Recommend consulting a professional installer who has done this type of VOV application before.