Putting wallpaper over wallpaper is a common question for homeowners looking to refresh a room without the hassle of complete removal. The short answer is generally yes, but success depends on several critical factors including the condition of the existing layer, the type of new material, and the preparation process. Understanding these variables is essential to avoid a costly and time-consuming mistake that leads to peeling bubbles or a ruined finish.
Assessing the Current Wall Surface
The foundation of any overlay project is the integrity of the existing wallpaper. You must first determine what the current layer is made of and how securely it is adhering to the wall. Peel a small section away from the wall to inspect the substrate; if it is thick and fibrous, it might be a traditional paper that will shed fibers under new adhesive. Smooth, non-woven surfaces often provide a better grip, while vinyl-coated walls can be slippery and require special bonding agents to ensure the new layer sticks properly.
Testing for Stability and Cleanliness
Before proceeding, conduct a simple adhesion test by pressing a damp sponge against a corner to see if the surface rubs off onto the cloth. If the paper crumbles or leaves a colored residue, it is likely deteriorating and must be removed entirely rather than covered. Additionally, check for any loose edges or hollow sounds when tapping the wall, as these indicate that the old paper is separating from the plaster or drywall beneath, which will cause the new application to fail.
Material Compatibility and Selection
Not all wallpapers are created equal, and the material of the old surface dictates the type of new wallpaper you can use. If the existing layer is a heavy vinyl, attempting to stick a delicate paper on top will result in poor adherence and a wrinkled appearance. Conversely, applying a heavy material over a fragile old layer puts too much weight on the substrate, leading to sagging or tearing. Matching the weight and texture of the materials is a key strategy for a successful overlay.
Non-woven over non-woven: Generally the easiest combination for adhesion.
Vinyl over vinyl: Possible, but requires aggressive cleaning and strong bonding paste.
Paper over vinyl: Not recommended due to the slick surface and weight difference.
Fabric-backed vinyl: Can be effective for soundproofing but requires specific adhesives.
The Preparation Process
Skipping preparation is the primary reason wallpaper over wallpaper projects fail. The walls must be treated as if they are bare, even if they look clean. This involves washing the surface with a degreaser to remove dust and old paste residues, sanding down any glossy patches to create a rough texture for the new adhesive to grip, and filling any holes or seams with a high-quality spackle. If the existing paper has a subtle texture, lightly sanding it ensures the new layer lies flat without visible ridges.
Adhesive Selection and Application
Standard wallpaper paste may not be strong enough to hold a second layer, especially if the existing paper is heavy. You should opt for a premium bonding agent specifically designed for over existing wallpaper, which offers superior grab and flexibility. Apply the adhesive evenly to the old surface using a short-nap roller, ensuring full coverage without creating puddles. Some professionals recommend hanging the new paper in the opposite direction (if the old pattern has a nap) to distribute the stress across the wall.
Potential Risks and Limitations
While overlaying can save time and money, it does increase the wall's thickness, which can cause issues with electrical outlets, switches, and door frames. You may need to extend these fixtures outward slightly to ensure the doors and drawers operate smoothly. Furthermore, if the underlying paper absorbs moisture differently than the new layer, it can create shear stress that leads to cracking or seam bulging over time, particularly in high-humidity areas like bathrooms.
